diff --git a/android/arm64-v8a/include/v8/libplatform/libplatform-export.h b/android/arm64-v8a/include/v8/libplatform/libplatform-export.h
new file mode 100644
index 00000000..15618434
--- /dev/null
+++ b/android/arm64-v8a/include/v8/libplatform/libplatform-export.h
@@ -0,0 +1,29 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+
+#if defined(_WIN32)
+
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllexport)
+#elif USING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllimport)
+#else
+#define V8_PLATFORM_EXPORT
+#endif  // BUILDING_V8_PLATFORM_SHARED
+
+#else  // defined(_WIN32)
+
+// Setup for Linux shared library export.
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __attribute__((visibility("default")))
+#else
+#define V8_PLATFORM_EXPORT
+#endif
+
+#endif  // defined(_WIN32)
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
diff --git a/android/arm64-v8a/include/v8/libplatform/libplatform.h b/android/arm64-v8a/include/v8/libplatform/libplatform.h
new file mode 100644
index 00000000..e9450456
--- /dev/null
+++ b/android/arm64-v8a/include/v8/libplatform/libplatform.h
@@ -0,0 +1,78 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_H_
+
+#include "libplatform/libplatform-export.h"
+#include "libplatform/v8-tracing.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+namespace platform {
+
+enum class IdleTaskSupport { kDisabled, kEnabled };
+enum class InProcessStackDumping { kDisabled, kEnabled };
+
+enum class MessageLoopBehavior : bool {
+  kDoNotWait = false,
+  kWaitForWork = true
+};
+
+/**
+ * Returns a new instance of the default v8::Platform implementation.
+ *
+ * The caller will take ownership of the returned pointer. |thread_pool_size|
+ * is the number of worker threads to allocate for background jobs. If a value
+ * of zero is passed, a suitable default based on the current number of
+ * processors online will be chosen.
+ * If |idle_task_support| is enabled then the platform will accept idle
+ * tasks (IdleTasksEnabled will return true) and will rely on the embedder
+ * calling v8::platform::RunIdleTasks to process the idle tasks.
+ */
+V8_PLATFORM_EXPORT v8::Platform* CreateDefaultPlatform(
+    int thread_pool_size = 0,
+    IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
+    InProcessStackDumping in_process_stack_dumping =
+        InProcessStackDumping::kEnabled);
+
+/**
+ * Pumps the message loop for the given isolate.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * Returns true if a task was executed, and false otherwise. Unless requested
+ * through the |behavior| parameter, this call does not block if no task is
+ * pending. The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT bool PumpMessageLoop(
+    v8::Platform* platform, v8::Isolate* isolate,
+    MessageLoopBehavior behavior = MessageLoopBehavior::kDoNotWait);
+
+V8_PLATFORM_EXPORT void EnsureEventLoopInitialized(v8::Platform* platform,
+                                                   v8::Isolate* isolate);
+
+/**
+ * Runs pending idle tasks for at most |idle_time_in_seconds| seconds.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * This call does not block if no task is pending. The |platform| has to be
+ * created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void RunIdleTasks(v8::Platform* platform,
+                                     v8::Isolate* isolate,
+                                     double idle_time_in_seconds);
+
+/**
+ * Attempts to set the tracing controller for the given platform.
+ *
+ * The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void SetTracingController(
+    v8::Platform* platform,
+    v8::platform::tracing::TracingController* tracing_controller);
+
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_H_
diff --git a/android/arm64-v8a/include/v8/libplatform/v8-tracing.h b/android/arm64-v8a/include/v8/libplatform/v8-tracing.h
new file mode 100644
index 00000000..902f8ea9
--- /dev/null
+++ b/android/arm64-v8a/include/v8/libplatform/v8-tracing.h
@@ -0,0 +1,270 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_V8_TRACING_H_
+#define V8_LIBPLATFORM_V8_TRACING_H_
+
+#include <fstream>
+#include <memory>
+#include <unordered_set>
+#include <vector>
+
+#include "libplatform/libplatform-export.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+
+namespace base {
+class Mutex;
+}  // namespace base
+
+namespace platform {
+namespace tracing {
+
+const int kTraceMaxNumArgs = 2;
+
+class V8_PLATFORM_EXPORT TraceObject {
+ public:
+  union ArgValue {
+    bool as_bool;
+    uint64_t as_uint;
+    int64_t as_int;
+    double as_double;
+    const void* as_pointer;
+    const char* as_string;
+  };
+
+  TraceObject() {}
+  ~TraceObject();
+  void Initialize(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateDuration();
+  void InitializeForTesting(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags, int pid, int tid, int64_t ts, int64_t tts,
+      uint64_t duration, uint64_t cpu_duration);
+
+  int pid() const { return pid_; }
+  int tid() const { return tid_; }
+  char phase() const { return phase_; }
+  const uint8_t* category_enabled_flag() const {
+    return category_enabled_flag_;
+  }
+  const char* name() const { return name_; }
+  const char* scope() const { return scope_; }
+  uint64_t id() const { return id_; }
+  uint64_t bind_id() const { return bind_id_; }
+  int num_args() const { return num_args_; }
+  const char** arg_names() { return arg_names_; }
+  uint8_t* arg_types() { return arg_types_; }
+  ArgValue* arg_values() { return arg_values_; }
+  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables() {
+    return arg_convertables_;
+  }
+  unsigned int flags() const { return flags_; }
+  int64_t ts() { return ts_; }
+  int64_t tts() { return tts_; }
+  uint64_t duration() { return duration_; }
+  uint64_t cpu_duration() { return cpu_duration_; }
+
+ private:
+  int pid_;
+  int tid_;
+  char phase_;
+  const char* name_;
+  const char* scope_;
+  const uint8_t* category_enabled_flag_;
+  uint64_t id_;
+  uint64_t bind_id_;
+  int num_args_ = 0;
+  const char* arg_names_[kTraceMaxNumArgs];
+  uint8_t arg_types_[kTraceMaxNumArgs];
+  ArgValue arg_values_[kTraceMaxNumArgs];
+  std::unique_ptr<v8::ConvertableToTraceFormat>
+      arg_convertables_[kTraceMaxNumArgs];
+  char* parameter_copy_storage_ = nullptr;
+  unsigned int flags_;
+  int64_t ts_;
+  int64_t tts_;
+  uint64_t duration_;
+  uint64_t cpu_duration_;
+
+  // Disallow copy and assign
+  TraceObject(const TraceObject&) = delete;
+  void operator=(const TraceObject&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceWriter {
+ public:
+  TraceWriter() {}
+  virtual ~TraceWriter() {}
+  virtual void AppendTraceEvent(TraceObject* trace_event) = 0;
+  virtual void Flush() = 0;
+
+  static TraceWriter* CreateJSONTraceWriter(std::ostream& stream);
+
+ private:
+  // Disallow copy and assign
+  TraceWriter(const TraceWriter&) = delete;
+  void operator=(const TraceWriter&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBufferChunk {
+ public:
+  explicit TraceBufferChunk(uint32_t seq);
+
+  void Reset(uint32_t new_seq);
+  bool IsFull() const { return next_free_ == kChunkSize; }
+  TraceObject* AddTraceEvent(size_t* event_index);
+  TraceObject* GetEventAt(size_t index) { return &chunk_[index]; }
+
+  uint32_t seq() const { return seq_; }
+  size_t size() const { return next_free_; }
+
+  static const size_t kChunkSize = 64;
+
+ private:
+  size_t next_free_ = 0;
+  TraceObject chunk_[kChunkSize];
+  uint32_t seq_;
+
+  // Disallow copy and assign
+  TraceBufferChunk(const TraceBufferChunk&) = delete;
+  void operator=(const TraceBufferChunk&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBuffer {
+ public:
+  TraceBuffer() {}
+  virtual ~TraceBuffer() {}
+
+  virtual TraceObject* AddTraceEvent(uint64_t* handle) = 0;
+  virtual TraceObject* GetEventByHandle(uint64_t handle) = 0;
+  virtual bool Flush() = 0;
+
+  static const size_t kRingBufferChunks = 1024;
+
+  static TraceBuffer* CreateTraceBufferRingBuffer(size_t max_chunks,
+                                                  TraceWriter* trace_writer);
+
+ private:
+  // Disallow copy and assign
+  TraceBuffer(const TraceBuffer&) = delete;
+  void operator=(const TraceBuffer&) = delete;
+};
+
+// Options determines how the trace buffer stores data.
+enum TraceRecordMode {
+  // Record until the trace buffer is full.
+  RECORD_UNTIL_FULL,
+
+  // Record until the user ends the trace. The trace buffer is a fixed size
+  // and we use it as a ring buffer during recording.
+  RECORD_CONTINUOUSLY,
+
+  // Record until the trace buffer is full, but with a huge buffer size.
+  RECORD_AS_MUCH_AS_POSSIBLE,
+
+  // Echo to console. Events are discarded.
+  ECHO_TO_CONSOLE,
+};
+
+class V8_PLATFORM_EXPORT TraceConfig {
+ public:
+  typedef std::vector<std::string> StringList;
+
+  static TraceConfig* CreateDefaultTraceConfig();
+
+  TraceConfig() : enable_systrace_(false), enable_argument_filter_(false) {}
+  TraceRecordMode GetTraceRecordMode() const { return record_mode_; }
+  bool IsSystraceEnabled() const { return enable_systrace_; }
+  bool IsArgumentFilterEnabled() const { return enable_argument_filter_; }
+
+  void SetTraceRecordMode(TraceRecordMode mode) { record_mode_ = mode; }
+  void EnableSystrace() { enable_systrace_ = true; }
+  void EnableArgumentFilter() { enable_argument_filter_ = true; }
+
+  void AddIncludedCategory(const char* included_category);
+
+  bool IsCategoryGroupEnabled(const char* category_group) const;
+
+ private:
+  TraceRecordMode record_mode_;
+  bool enable_systrace_ : 1;
+  bool enable_argument_filter_ : 1;
+  StringList included_categories_;
+
+  // Disallow copy and assign
+  TraceConfig(const TraceConfig&) = delete;
+  void operator=(const TraceConfig&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TracingController {
+ public:
+  enum Mode { DISABLED = 0, RECORDING_MODE };
+
+  // The pointer returned from GetCategoryGroupEnabledInternal() points to a
+  // value with zero or more of the following bits. Used in this class only.
+  // The TRACE_EVENT macros should only use the value as a bool.
+  // These values must be in sync with macro values in TraceEvent.h in Blink.
+  enum CategoryGroupEnabledFlags {
+    // Category group enabled for the recording mode.
+    ENABLED_FOR_RECORDING = 1 << 0,
+    // Category group enabled by SetEventCallbackEnabled().
+    ENABLED_FOR_EVENT_CALLBACK = 1 << 2,
+    // Category group enabled to export events to ETW.
+    ENABLED_FOR_ETW_EXPORT = 1 << 3
+  };
+
+  TracingController();
+  ~TracingController();
+  void Initialize(TraceBuffer* trace_buffer);
+  const uint8_t* GetCategoryGroupEnabled(const char* category_group);
+  static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
+  uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                const char* name, uint64_t handle);
+
+  void StartTracing(TraceConfig* trace_config);
+  void StopTracing();
+
+  void AddTraceStateObserver(Platform::TraceStateObserver* observer);
+  void RemoveTraceStateObserver(Platform::TraceStateObserver* observer);
+
+ private:
+  const uint8_t* GetCategoryGroupEnabledInternal(const char* category_group);
+  void UpdateCategoryGroupEnabledFlag(size_t category_index);
+  void UpdateCategoryGroupEnabledFlags();
+
+  std::unique_ptr<TraceBuffer> trace_buffer_;
+  std::unique_ptr<TraceConfig> trace_config_;
+  std::unique_ptr<base::Mutex> mutex_;
+  std::unordered_set<Platform::TraceStateObserver*> observers_;
+  Mode mode_ = DISABLED;
+
+  // Disallow copy and assign
+  TracingController(const TracingController&) = delete;
+  void operator=(const TracingController&) = delete;
+};
+
+}  // namespace tracing
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_V8_TRACING_H_
diff --git a/android/arm64-v8a/include/v8/v8-debug.h b/android/arm64-v8a/include/v8/v8-debug.h
new file mode 100644
index 00000000..54c0f216
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-debug.h
@@ -0,0 +1,255 @@
+// Copyright 2008 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_DEBUG_H_
+#define V8_V8_DEBUG_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * ATTENTION: The debugger API exposed by this file is deprecated and will be
+ *            removed by the end of 2017. Please use the V8 inspector declared
+ *            in include/v8-inspector.h instead.
+ */
+namespace v8 {
+
+// Debug events which can occur in the V8 JavaScript engine.
+enum DebugEvent {
+  Break = 1,
+  Exception = 2,
+  AfterCompile = 3,
+  CompileError = 4,
+  AsyncTaskEvent = 5,
+};
+
+class V8_EXPORT Debug {
+ public:
+  /**
+   * A client object passed to the v8 debugger whose ownership will be taken by
+   * it. v8 is always responsible for deleting the object.
+   */
+  class ClientData {
+   public:
+    virtual ~ClientData() {}
+  };
+
+
+  /**
+   * A message object passed to the debug message handler.
+   */
+  class Message {
+   public:
+    /**
+     * Check type of message.
+     */
+    virtual bool IsEvent() const = 0;
+    virtual bool IsResponse() const = 0;
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Indicate whether this is a response to a continue command which will
+     * start the VM running after this is processed.
+     */
+    virtual bool WillStartRunning() const = 0;
+
+    /**
+     * Access to execution state and event data. Don't store these cross
+     * callbacks as their content becomes invalid. These objects are from the
+     * debugger event that started the debug message loop.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the debugger protocol JSON.
+     */
+    virtual Local<String> GetJSON() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding request if any. This is the
+     * client_data data value passed into Debug::SendCommand along with the
+     * request that led to the message or NULL if the message is an event. The
+     * debugger takes ownership of the data and will delete it even if there is
+     * no message handler.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~Message() {}
+  };
+
+  /**
+   * An event details object passed to the debug event listener.
+   */
+  class EventDetails {
+   public:
+    /**
+     * Event type.
+     */
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Access to execution state and event data of the debug event. Don't store
+     * these cross callbacks as their content becomes invalid.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding callback when it was
+     * registered.
+     */
+    virtual Local<Value> GetCallbackData() const = 0;
+
+    /**
+     * This is now a dummy that returns nullptr.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~EventDetails() {}
+  };
+
+  /**
+   * Debug event callback function.
+   *
+   * \param event_details object providing information about the debug event
+   *
+   * A EventCallback does not take possession of the event data,
+   * and must not rely on the data persisting after the handler returns.
+   */
+  typedef void (*EventCallback)(const EventDetails& event_details);
+
+  /**
+   * This is now a no-op.
+   */
+  typedef void (*MessageHandler)(const Message& message);
+
+  V8_DEPRECATED("No longer supported", static bool SetDebugEventListener(
+                                           Isolate* isolate, EventCallback that,
+                                           Local<Value> data = Local<Value>()));
+
+  // Schedule a debugger break to happen when JavaScript code is run
+  // in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static void DebugBreak(Isolate* isolate));
+
+  // Remove scheduled debugger break in given isolate if it has not
+  // happened yet.
+  V8_DEPRECATED("No longer supported",
+                static void CancelDebugBreak(Isolate* isolate));
+
+  // Check if a debugger break is scheduled in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static bool CheckDebugBreak(Isolate* isolate));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SetMessageHandler(Isolate* isolate,
+                                              MessageHandler handler));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SendCommand(Isolate* isolate,
+                                        const uint16_t* command, int length,
+                                        ClientData* client_data = NULL));
+
+  /**
+   * Run a JavaScript function in the debugger.
+   * \param fun the function to call
+   * \param data passed as second argument to the function
+   * With this call the debugger is entered and the function specified is called
+   * with the execution state as the first argument. This makes it possible to
+   * get access to information otherwise not available during normal JavaScript
+   * execution e.g. details on stack frames. Receiver of the function call will
+   * be the debugger context global object, however this is a subject to change.
+   * The following example shows a JavaScript function which when passed to
+   * v8::Debug::Call will return the current line of JavaScript execution.
+   *
+   * \code
+   *   function frame_source_line(exec_state) {
+   *     return exec_state.frame(0).sourceLine();
+   *   }
+   * \endcode
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Value> Call(
+                    Local<Context> context, v8::Local<v8::Function> fun,
+                    Local<Value> data = Local<Value>()));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void ProcessDebugMessages(Isolate* isolate));
+
+  /**
+   * Debugger is running in its own context which is entered while debugger
+   * messages are being dispatched. This is an explicit getter for this
+   * debugger context. Note that the content of the debugger context is subject
+   * to change. The Context exists only when the debugger is active, i.e. at
+   * least one DebugEventListener or MessageHandler is set.
+   */
+  V8_DEPRECATED("Use v8-inspector",
+                static Local<Context> GetDebugContext(Isolate* isolate));
+
+  /**
+   * While in the debug context, this method returns the top-most non-debug
+   * context, if it exists.
+   */
+  V8_DEPRECATED(
+      "No longer supported",
+      static MaybeLocal<Context> GetDebuggedContext(Isolate* isolate));
+
+  /**
+   * Enable/disable LiveEdit functionality for the given Isolate
+   * (default Isolate if not provided). V8 will abort if LiveEdit is
+   * unexpectedly used. LiveEdit is enabled by default.
+   */
+  V8_DEPRECATED("No longer supported",
+                static void SetLiveEditEnabled(Isolate* isolate, bool enable));
+
+  /**
+   * Returns array of internal properties specific to the value type. Result has
+   * the following format: [<name>, <value>,...,<name>, <value>]. Result array
+   * will be allocated in the current context.
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Array> GetInternalProperties(
+                    Isolate* isolate, Local<Value> value));
+
+  /**
+   * Defines if the ES2015 tail call elimination feature is enabled or not.
+   * The change of this flag triggers deoptimization of all functions that
+   * contain calls at tail position.
+   */
+  V8_DEPRECATED("No longer supported",
+                static bool IsTailCallEliminationEnabled(Isolate* isolate));
+  V8_DEPRECATED("No longer supported",
+                static void SetTailCallEliminationEnabled(Isolate* isolate,
+                                                          bool enabled));
+};
+
+
+}  // namespace v8
+
+
+#undef EXPORT
+
+
+#endif  // V8_V8_DEBUG_H_
diff --git a/android/arm64-v8a/include/v8/v8-inspector-protocol.h b/android/arm64-v8a/include/v8/v8-inspector-protocol.h
new file mode 100644
index 00000000..612a2ebc
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-inspector-protocol.h
@@ -0,0 +1,13 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_PROTOCOL_H_
+#define V8_V8_INSPECTOR_PROTOCOL_H_
+
+#include "inspector/Debugger.h"  // NOLINT(build/include)
+#include "inspector/Runtime.h"   // NOLINT(build/include)
+#include "inspector/Schema.h"    // NOLINT(build/include)
+#include "v8-inspector.h"        // NOLINT(build/include)
+
+#endif  // V8_V8_INSPECTOR_PROTOCOL_H_
diff --git a/android/arm64-v8a/include/v8/v8-inspector.h b/android/arm64-v8a/include/v8/v8-inspector.h
new file mode 100644
index 00000000..43bf3b4f
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-inspector.h
@@ -0,0 +1,267 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_H_
+#define V8_V8_INSPECTOR_H_
+
+#include <stdint.h>
+#include <cctype>
+
+#include <memory>
+
+#include "v8.h"  // NOLINT(build/include)
+
+namespace v8_inspector {
+
+namespace protocol {
+namespace Debugger {
+namespace API {
+class SearchMatch;
+}
+}
+namespace Runtime {
+namespace API {
+class RemoteObject;
+class StackTrace;
+}
+}
+namespace Schema {
+namespace API {
+class Domain;
+}
+}
+}  // namespace protocol
+
+class V8_EXPORT StringView {
+ public:
+  StringView() : m_is8Bit(true), m_length(0), m_characters8(nullptr) {}
+
+  StringView(const uint8_t* characters, size_t length)
+      : m_is8Bit(true), m_length(length), m_characters8(characters) {}
+
+  StringView(const uint16_t* characters, size_t length)
+      : m_is8Bit(false), m_length(length), m_characters16(characters) {}
+
+  bool is8Bit() const { return m_is8Bit; }
+  size_t length() const { return m_length; }
+
+  // TODO(dgozman): add DCHECK(m_is8Bit) to accessors once platform can be used
+  // here.
+  const uint8_t* characters8() const { return m_characters8; }
+  const uint16_t* characters16() const { return m_characters16; }
+
+ private:
+  bool m_is8Bit;
+  size_t m_length;
+  union {
+    const uint8_t* m_characters8;
+    const uint16_t* m_characters16;
+  };
+};
+
+class V8_EXPORT StringBuffer {
+ public:
+  virtual ~StringBuffer() {}
+  virtual const StringView& string() = 0;
+  // This method copies contents.
+  static std::unique_ptr<StringBuffer> create(const StringView&);
+};
+
+class V8_EXPORT V8ContextInfo {
+ public:
+  V8ContextInfo(v8::Local<v8::Context> context, int contextGroupId,
+                const StringView& humanReadableName)
+      : context(context),
+        contextGroupId(contextGroupId),
+        humanReadableName(humanReadableName),
+        hasMemoryOnConsole(false) {}
+
+  v8::Local<v8::Context> context;
+  // Each v8::Context is a part of a group. The group id must be non-zero.
+  int contextGroupId;
+  StringView humanReadableName;
+  StringView origin;
+  StringView auxData;
+  bool hasMemoryOnConsole;
+
+  static int executionContextId(v8::Local<v8::Context> context);
+
+ private:
+  // Disallow copying and allocating this one.
+  enum NotNullTagEnum { NotNullLiteral };
+  void* operator new(size_t) = delete;
+  void* operator new(size_t, NotNullTagEnum, void*) = delete;
+  void* operator new(size_t, void*) = delete;
+  V8ContextInfo(const V8ContextInfo&) = delete;
+  V8ContextInfo& operator=(const V8ContextInfo&) = delete;
+};
+
+class V8_EXPORT V8StackTrace {
+ public:
+  virtual bool isEmpty() const = 0;
+  virtual StringView topSourceURL() const = 0;
+  virtual int topLineNumber() const = 0;
+  virtual int topColumnNumber() const = 0;
+  virtual StringView topScriptId() const = 0;
+  virtual StringView topFunctionName() const = 0;
+
+  virtual ~V8StackTrace() {}
+  virtual std::unique_ptr<protocol::Runtime::API::StackTrace>
+  buildInspectorObject() const = 0;
+  virtual std::unique_ptr<StringBuffer> toString() const = 0;
+
+  // Safe to pass between threads, drops async chain.
+  virtual std::unique_ptr<V8StackTrace> clone() = 0;
+};
+
+class V8_EXPORT V8InspectorSession {
+ public:
+  virtual ~V8InspectorSession() {}
+
+  // Cross-context inspectable values (DOM nodes in different worlds, etc.).
+  class V8_EXPORT Inspectable {
+   public:
+    virtual v8::Local<v8::Value> get(v8::Local<v8::Context>) = 0;
+    virtual ~Inspectable() {}
+  };
+  virtual void addInspectedObject(std::unique_ptr<Inspectable>) = 0;
+
+  // Dispatching protocol messages.
+  static bool canDispatchMethod(const StringView& method);
+  virtual void dispatchProtocolMessage(const StringView& message) = 0;
+  virtual std::unique_ptr<StringBuffer> stateJSON() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Schema::API::Domain>>
+  supportedDomains() = 0;
+
+  // Debugger actions.
+  virtual void schedulePauseOnNextStatement(const StringView& breakReason,
+                                            const StringView& breakDetails) = 0;
+  virtual void cancelPauseOnNextStatement() = 0;
+  virtual void breakProgram(const StringView& breakReason,
+                            const StringView& breakDetails) = 0;
+  virtual void setSkipAllPauses(bool) = 0;
+  virtual void resume() = 0;
+  virtual void stepOver() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Debugger::API::SearchMatch>>
+  searchInTextByLines(const StringView& text, const StringView& query,
+                      bool caseSensitive, bool isRegex) = 0;
+
+  // Remote objects.
+  virtual std::unique_ptr<protocol::Runtime::API::RemoteObject> wrapObject(
+      v8::Local<v8::Context>, v8::Local<v8::Value>,
+      const StringView& groupName) = 0;
+  virtual bool unwrapObject(std::unique_ptr<StringBuffer>* error,
+                            const StringView& objectId, v8::Local<v8::Value>*,
+                            v8::Local<v8::Context>*,
+                            std::unique_ptr<StringBuffer>* objectGroup) = 0;
+  virtual void releaseObjectGroup(const StringView&) = 0;
+};
+
+class V8_EXPORT V8InspectorClient {
+ public:
+  virtual ~V8InspectorClient() {}
+
+  virtual void runMessageLoopOnPause(int contextGroupId) {}
+  virtual void quitMessageLoopOnPause() {}
+  virtual void runIfWaitingForDebugger(int contextGroupId) {}
+
+  virtual void muteMetrics(int contextGroupId) {}
+  virtual void unmuteMetrics(int contextGroupId) {}
+
+  virtual void beginUserGesture() {}
+  virtual void endUserGesture() {}
+
+  virtual std::unique_ptr<StringBuffer> valueSubtype(v8::Local<v8::Value>) {
+    return nullptr;
+  }
+  virtual bool formatAccessorsAsProperties(v8::Local<v8::Value>) {
+    return false;
+  }
+  virtual bool isInspectableHeapObject(v8::Local<v8::Object>) { return true; }
+
+  virtual v8::Local<v8::Context> ensureDefaultContextInGroup(
+      int contextGroupId) {
+    return v8::Local<v8::Context>();
+  }
+  virtual void beginEnsureAllContextsInGroup(int contextGroupId) {}
+  virtual void endEnsureAllContextsInGroup(int contextGroupId) {}
+
+  virtual void installAdditionalCommandLineAPI(v8::Local<v8::Context>,
+                                               v8::Local<v8::Object>) {}
+  virtual void consoleAPIMessage(int contextGroupId,
+                                 v8::Isolate::MessageErrorLevel level,
+                                 const StringView& message,
+                                 const StringView& url, unsigned lineNumber,
+                                 unsigned columnNumber, V8StackTrace*) {}
+  virtual v8::MaybeLocal<v8::Value> memoryInfo(v8::Isolate*,
+                                               v8::Local<v8::Context>) {
+    return v8::MaybeLocal<v8::Value>();
+  }
+
+  virtual void consoleTime(const StringView& title) {}
+  virtual void consoleTimeEnd(const StringView& title) {}
+  virtual void consoleTimeStamp(const StringView& title) {}
+  virtual void consoleClear(int contextGroupId) {}
+  virtual double currentTimeMS() { return 0; }
+  typedef void (*TimerCallback)(void*);
+  virtual void startRepeatingTimer(double, TimerCallback, void* data) {}
+  virtual void cancelTimer(void* data) {}
+
+  // TODO(dgozman): this was added to support service worker shadow page. We
+  // should not connect at all.
+  virtual bool canExecuteScripts(int contextGroupId) { return true; }
+};
+
+class V8_EXPORT V8Inspector {
+ public:
+  static std::unique_ptr<V8Inspector> create(v8::Isolate*, V8InspectorClient*);
+  virtual ~V8Inspector() {}
+
+  // Contexts instrumentation.
+  virtual void contextCreated(const V8ContextInfo&) = 0;
+  virtual void contextDestroyed(v8::Local<v8::Context>) = 0;
+  virtual void resetContextGroup(int contextGroupId) = 0;
+
+  // Various instrumentation.
+  virtual void idleStarted() = 0;
+  virtual void idleFinished() = 0;
+
+  // Async stack traces instrumentation.
+  virtual void asyncTaskScheduled(const StringView& taskName, void* task,
+                                  bool recurring) = 0;
+  virtual void asyncTaskCanceled(void* task) = 0;
+  virtual void asyncTaskStarted(void* task) = 0;
+  virtual void asyncTaskFinished(void* task) = 0;
+  virtual void allAsyncTasksCanceled() = 0;
+
+  // Exceptions instrumentation.
+  virtual unsigned exceptionThrown(
+      v8::Local<v8::Context>, const StringView& message,
+      v8::Local<v8::Value> exception, const StringView& detailedMessage,
+      const StringView& url, unsigned lineNumber, unsigned columnNumber,
+      std::unique_ptr<V8StackTrace>, int scriptId) = 0;
+  virtual void exceptionRevoked(v8::Local<v8::Context>, unsigned exceptionId,
+                                const StringView& message) = 0;
+
+  // Connection.
+  class V8_EXPORT Channel {
+   public:
+    virtual ~Channel() {}
+    virtual void sendResponse(int callId,
+                              std::unique_ptr<StringBuffer> message) = 0;
+    virtual void sendNotification(std::unique_ptr<StringBuffer> message) = 0;
+    virtual void flushProtocolNotifications() = 0;
+  };
+  virtual std::unique_ptr<V8InspectorSession> connect(
+      int contextGroupId, Channel*, const StringView& state) = 0;
+
+  // API methods.
+  virtual std::unique_ptr<V8StackTrace> createStackTrace(
+      v8::Local<v8::StackTrace>) = 0;
+  virtual std::unique_ptr<V8StackTrace> captureStackTrace(bool fullStack) = 0;
+};
+
+}  // namespace v8_inspector
+
+#endif  // V8_V8_INSPECTOR_H_
diff --git a/android/arm64-v8a/include/v8/v8-platform.h b/android/arm64-v8a/include/v8/v8-platform.h
new file mode 100644
index 00000000..8f6d8042
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-platform.h
@@ -0,0 +1,227 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PLATFORM_H_
+#define V8_V8_PLATFORM_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <memory>
+#include <string>
+
+namespace v8 {
+
+class Isolate;
+
+/**
+ * A Task represents a unit of work.
+ */
+class Task {
+ public:
+  virtual ~Task() = default;
+
+  virtual void Run() = 0;
+};
+
+/**
+ * An IdleTask represents a unit of work to be performed in idle time.
+ * The Run method is invoked with an argument that specifies the deadline in
+ * seconds returned by MonotonicallyIncreasingTime().
+ * The idle task is expected to complete by this deadline.
+ */
+class IdleTask {
+ public:
+  virtual ~IdleTask() = default;
+  virtual void Run(double deadline_in_seconds) = 0;
+};
+
+/**
+ * The interface represents complex arguments to trace events.
+ */
+class ConvertableToTraceFormat {
+ public:
+  virtual ~ConvertableToTraceFormat() = default;
+
+  /**
+   * Append the class info to the provided |out| string. The appended
+   * data must be a valid JSON object. Strings must be properly quoted, and
+   * escaped. There is no processing applied to the content after it is
+   * appended.
+   */
+  virtual void AppendAsTraceFormat(std::string* out) const = 0;
+};
+
+/**
+ * V8 Platform abstraction layer.
+ *
+ * The embedder has to provide an implementation of this interface before
+ * initializing the rest of V8.
+ */
+class Platform {
+ public:
+  /**
+   * This enum is used to indicate whether a task is potentially long running,
+   * or causes a long wait. The embedder might want to use this hint to decide
+   * whether to execute the task on a dedicated thread.
+   */
+  enum ExpectedRuntime {
+    kShortRunningTask,
+    kLongRunningTask
+  };
+
+  virtual ~Platform() = default;
+
+  /**
+   * Gets the number of threads that are used to execute background tasks. Is
+   * used to estimate the number of tasks a work package should be split into.
+   * A return value of 0 means that there are no background threads available.
+   * Note that a value of 0 won't prohibit V8 from posting tasks using
+   * |CallOnBackgroundThread|.
+   */
+  virtual size_t NumberOfAvailableBackgroundThreads() { return 0; }
+
+  /**
+   * Schedules a task to be invoked on a background thread. |expected_runtime|
+   * indicates that the task will run a long time. The Platform implementation
+   * takes ownership of |task|. There is no guarantee about order of execution
+   * of tasks wrt order of scheduling, nor is there a guarantee about the
+   * thread the task will be run on.
+   */
+  virtual void CallOnBackgroundThread(Task* task,
+                                      ExpectedRuntime expected_runtime) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate|. Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallOnForegroundThread(Isolate* isolate, Task* task) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| after the given number of seconds |delay_in_seconds|.
+   * Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallDelayedOnForegroundThread(Isolate* isolate, Task* task,
+                                             double delay_in_seconds) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| when the embedder is idle.
+   * Requires that SupportsIdleTasks(isolate) is true.
+   * Idle tasks may be reordered relative to other task types and may be
+   * starved for an arbitrarily long time if no idle time is available.
+   * The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallIdleOnForegroundThread(Isolate* isolate, IdleTask* task) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+  }
+
+  /**
+   * Returns true if idle tasks are enabled for the given |isolate|.
+   */
+  virtual bool IdleTasksEnabled(Isolate* isolate) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+    return false;
+  }
+
+  /**
+   * Monotonically increasing time in seconds from an arbitrary fixed point in
+   * the past. This function is expected to return at least
+   * millisecond-precision values. For this reason,
+   * it is recommended that the fixed point be no further in the past than
+   * the epoch.
+   **/
+  virtual double MonotonicallyIncreasingTime() = 0;
+
+  /**
+   * Called by TRACE_EVENT* macros, don't call this directly.
+   * The name parameter is a category group for example:
+   * TRACE_EVENT0("v8,parse", "V8.Parse")
+   * The pointer returned points to a value with zero or more of the bits
+   * defined in CategoryGroupEnabledFlags.
+   **/
+  virtual const uint8_t* GetCategoryGroupEnabled(const char* name) {
+    static uint8_t no = 0;
+    return &no;
+  }
+
+  /**
+   * Gets the category group name of the given category_enabled_flag pointer.
+   * Usually used while serliazing TRACE_EVENTs.
+   **/
+  virtual const char* GetCategoryGroupName(
+      const uint8_t* category_enabled_flag) {
+    static const char dummy[] = "dummy";
+    return dummy;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values, unsigned int flags) {
+    return 0;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags) {
+    return AddTraceEvent(phase, category_enabled_flag, name, scope, id, bind_id,
+                         num_args, arg_names, arg_types, arg_values, flags);
+  }
+
+  /**
+   * Sets the duration field of a COMPLETE trace event. It must be called with
+   * the handle returned from AddTraceEvent().
+   **/
+  virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                        const char* name, uint64_t handle) {}
+
+  class TraceStateObserver {
+   public:
+    virtual ~TraceStateObserver() = default;
+    virtual void OnTraceEnabled() = 0;
+    virtual void OnTraceDisabled() = 0;
+  };
+
+  /** Adds tracing state change observer. */
+  virtual void AddTraceStateObserver(TraceStateObserver*) {}
+
+  /** Removes tracing state change observer. */
+  virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
+
+  typedef void (*StackTracePrinter)();
+
+  /**
+   * Returns a function pointer that print a stack trace of the current stack
+   * on invocation. Disables printing of the stack trace if nullptr.
+   */
+  virtual StackTracePrinter GetStackTracePrinter() { return nullptr; }
+};
+
+}  // namespace v8
+
+#endif  // V8_V8_PLATFORM_H_
diff --git a/android/arm64-v8a/include/v8/v8-profiler.h b/android/arm64-v8a/include/v8/v8-profiler.h
new file mode 100644
index 00000000..b60d137f
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-profiler.h
@@ -0,0 +1,912 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PROFILER_H_
+#define V8_V8_PROFILER_H_
+
+#include <unordered_set>
+#include <vector>
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Profiler support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class HeapGraphNode;
+struct HeapStatsUpdate;
+
+typedef uint32_t SnapshotObjectId;
+
+
+struct CpuProfileDeoptFrame {
+  int script_id;
+  size_t position;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptFrame>;
+#endif
+
+namespace v8 {
+
+struct V8_EXPORT CpuProfileDeoptInfo {
+  /** A pointer to a static string owned by v8. */
+  const char* deopt_reason;
+  std::vector<CpuProfileDeoptFrame> stack;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>;
+#endif
+
+namespace v8 {
+
+/**
+ * TracingCpuProfiler monitors tracing being enabled/disabled
+ * and emits CpuProfile trace events once v8.cpu_profiler tracing category
+ * is enabled. It has no overhead unless the category is enabled.
+ */
+class V8_EXPORT TracingCpuProfiler {
+ public:
+  static std::unique_ptr<TracingCpuProfiler> Create(Isolate*);
+  virtual ~TracingCpuProfiler() = default;
+
+ protected:
+  TracingCpuProfiler() = default;
+};
+
+// TickSample captures the information collected for each sample.
+struct TickSample {
+  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
+  // include the runtime function we're calling. Externally exposed tick
+  // samples don't care.
+  enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame };
+
+  TickSample()
+      : state(OTHER),
+        pc(nullptr),
+        external_callback_entry(nullptr),
+        frames_count(0),
+        has_external_callback(false),
+        update_stats(true) {}
+
+  /**
+   * Initialize a tick sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Execution state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param update_stats Whether update the sample to the aggregated stats.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   */
+  void Init(Isolate* isolate, const v8::RegisterState& state,
+            RecordCEntryFrame record_c_entry_frame, bool update_stats,
+            bool use_simulator_reg_state = true);
+  /**
+   * Get a call stack sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Register state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   * \note GetStackSample is thread and signal safe and should only be called
+   *                      when the JS thread is paused or interrupted.
+   *                      Otherwise the behavior is undefined.
+   */
+  static bool GetStackSample(Isolate* isolate, v8::RegisterState* state,
+                             RecordCEntryFrame record_c_entry_frame,
+                             void** frames, size_t frames_limit,
+                             v8::SampleInfo* sample_info,
+                             bool use_simulator_reg_state = true);
+  StateTag state;  // The state of the VM.
+  void* pc;        // Instruction pointer.
+  union {
+    void* tos;  // Top stack value (*sp).
+    void* external_callback_entry;
+  };
+  static const unsigned kMaxFramesCountLog2 = 8;
+  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
+  void* stack[kMaxFramesCount];                 // Call stack.
+  unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
+  bool has_external_callback : 1;
+  bool update_stats : 1;  // Whether the sample should update aggregated stats.
+};
+
+/**
+ * CpuProfileNode represents a node in a call graph.
+ */
+class V8_EXPORT CpuProfileNode {
+ public:
+  struct LineTick {
+    /** The 1-based number of the source line where the function originates. */
+    int line;
+
+    /** The count of samples associated with the source line. */
+    unsigned int hit_count;
+  };
+
+  /** Returns function name (empty string for anonymous functions.) */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns function name (empty string for anonymous functions.)
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetFunctionNameStr() const;
+
+  /** Returns id of the script where function is located. */
+  int GetScriptId() const;
+
+  /** Returns resource name for script from where the function originates. */
+  Local<String> GetScriptResourceName() const;
+
+  /**
+   * Returns resource name for script from where the function originates.
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetScriptResourceNameStr() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the function originates.
+   * kNoLineNumberInfo if no line number information is available.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns 1-based number of the column where the function originates.
+   * kNoColumnNumberInfo if no column number information is available.
+   */
+  int GetColumnNumber() const;
+
+  /**
+   * Returns the number of the function's source lines that collect the samples.
+   */
+  unsigned int GetHitLineCount() const;
+
+  /** Returns the set of source lines that collect the samples.
+   *  The caller allocates buffer and responsible for releasing it.
+   *  True if all available entries are copied, otherwise false.
+   *  The function copies nothing if buffer is not large enough.
+   */
+  bool GetLineTicks(LineTick* entries, unsigned int length) const;
+
+  /** Returns bailout reason for the function
+    * if the optimization was disabled for it.
+    */
+  const char* GetBailoutReason() const;
+
+  /**
+    * Returns the count of samples where the function was currently executing.
+    */
+  unsigned GetHitCount() const;
+
+  /** Returns function entry UID. */
+  V8_DEPRECATE_SOON(
+      "Use GetScriptId, GetLineNumber, and GetColumnNumber instead.",
+      unsigned GetCallUid() const);
+
+  /** Returns id of the node. The id is unique within the tree */
+  unsigned GetNodeId() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child node by index. */
+  const CpuProfileNode* GetChild(int index) const;
+
+  /** Retrieves deopt infos for the node. */
+  const std::vector<CpuProfileDeoptInfo>& GetDeoptInfos() const;
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * CpuProfile contains a CPU profile in a form of top-down call tree
+ * (from main() down to functions that do all the work).
+ */
+class V8_EXPORT CpuProfile {
+ public:
+  /** Returns CPU profile title. */
+  Local<String> GetTitle() const;
+
+  /** Returns the root node of the top down call tree. */
+  const CpuProfileNode* GetTopDownRoot() const;
+
+  /**
+   * Returns number of samples recorded. The samples are not recorded unless
+   * |record_samples| parameter of CpuProfiler::StartCpuProfiling is true.
+   */
+  int GetSamplesCount() const;
+
+  /**
+   * Returns profile node corresponding to the top frame the sample at
+   * the given index.
+   */
+  const CpuProfileNode* GetSample(int index) const;
+
+  /**
+   * Returns the timestamp of the sample. The timestamp is the number of
+   * microseconds since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetSampleTimestamp(int index) const;
+
+  /**
+   * Returns time when the profile recording was started (in microseconds)
+   * since some unspecified starting point.
+   */
+  int64_t GetStartTime() const;
+
+  /**
+   * Returns time when the profile recording was stopped (in microseconds)
+   * since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetEndTime() const;
+
+  /**
+   * Deletes the profile and removes it from CpuProfiler's list.
+   * All pointers to nodes previously returned become invalid.
+   */
+  void Delete();
+};
+
+/**
+ * Interface for controlling CPU profiling. Instance of the
+ * profiler can be created using v8::CpuProfiler::New method.
+ */
+class V8_EXPORT CpuProfiler {
+ public:
+  /**
+   * Creates a new CPU profiler for the |isolate|. The isolate must be
+   * initialized. The profiler object must be disposed after use by calling
+   * |Dispose| method.
+   */
+  static CpuProfiler* New(Isolate* isolate);
+
+  /**
+   * Disposes the CPU profiler object.
+   */
+  void Dispose();
+
+  /**
+   * Changes default CPU profiler sampling interval to the specified number
+   * of microseconds. Default interval is 1000us. This method must be called
+   * when there are no profiles being recorded.
+   */
+  void SetSamplingInterval(int us);
+
+  /**
+   * Starts collecting CPU profile. Title may be an empty string. It
+   * is allowed to have several profiles being collected at
+   * once. Attempts to start collecting several profiles with the same
+   * title are silently ignored. While collecting a profile, functions
+   * from all security contexts are included in it. The token-based
+   * filtering is only performed when querying for a profile.
+   *
+   * |record_samples| parameter controls whether individual samples should
+   * be recorded in addition to the aggregated tree.
+   */
+  void StartProfiling(Local<String> title, bool record_samples = false);
+
+  /**
+   * Stops collecting CPU profile with a given title and returns it.
+   * If the title given is empty, finishes the last profile started.
+   */
+  CpuProfile* StopProfiling(Local<String> title);
+
+  /**
+   * Force collection of a sample. Must be called on the VM thread.
+   * Recording the forced sample does not contribute to the aggregated
+   * profile statistics.
+   */
+  void CollectSample();
+
+  /**
+   * Tells the profiler whether the embedder is idle.
+   */
+  void SetIdle(bool is_idle);
+
+ private:
+  CpuProfiler();
+  ~CpuProfiler();
+  CpuProfiler(const CpuProfiler&);
+  CpuProfiler& operator=(const CpuProfiler&);
+};
+
+
+/**
+ * HeapSnapshotEdge represents a directed connection between heap
+ * graph nodes: from retainers to retained nodes.
+ */
+class V8_EXPORT HeapGraphEdge {
+ public:
+  enum Type {
+    kContextVariable = 0,  // A variable from a function context.
+    kElement = 1,          // An element of an array.
+    kProperty = 2,         // A named object property.
+    kInternal = 3,         // A link that can't be accessed from JS,
+                           // thus, its name isn't a real property name
+                           // (e.g. parts of a ConsString).
+    kHidden = 4,           // A link that is needed for proper sizes
+                           // calculation, but may be hidden from user.
+    kShortcut = 5,         // A link that must not be followed during
+                           // sizes calculation.
+    kWeak = 6              // A weak reference (ignored by the GC).
+  };
+
+  /** Returns edge type (see HeapGraphEdge::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns edge name. This can be a variable name, an element index, or
+   * a property name.
+   */
+  Local<Value> GetName() const;
+
+  /** Returns origin node. */
+  const HeapGraphNode* GetFromNode() const;
+
+  /** Returns destination node. */
+  const HeapGraphNode* GetToNode() const;
+};
+
+
+/**
+ * HeapGraphNode represents a node in a heap graph.
+ */
+class V8_EXPORT HeapGraphNode {
+ public:
+  enum Type {
+    kHidden = 0,         // Hidden node, may be filtered when shown to user.
+    kArray = 1,          // An array of elements.
+    kString = 2,         // A string.
+    kObject = 3,         // A JS object (except for arrays and strings).
+    kCode = 4,           // Compiled code.
+    kClosure = 5,        // Function closure.
+    kRegExp = 6,         // RegExp.
+    kHeapNumber = 7,     // Number stored in the heap.
+    kNative = 8,         // Native object (not from V8 heap).
+    kSynthetic = 9,      // Synthetic object, usualy used for grouping
+                         // snapshot items together.
+    kConsString = 10,    // Concatenated string. A pair of pointers to strings.
+    kSlicedString = 11,  // Sliced string. A fragment of another string.
+    kSymbol = 12         // A Symbol (ES6).
+  };
+
+  /** Returns node type (see HeapGraphNode::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns node name. Depending on node's type this can be the name
+   * of the constructor (for objects), the name of the function (for
+   * closures), string value, or an empty string (for compiled code).
+   */
+  Local<String> GetName() const;
+
+  /**
+   * Returns node id. For the same heap object, the id remains the same
+   * across all snapshots.
+   */
+  SnapshotObjectId GetId() const;
+
+  /** Returns node's own size, in bytes. */
+  size_t GetShallowSize() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child by index. */
+  const HeapGraphEdge* GetChild(int index) const;
+};
+
+
+/**
+ * An interface for exporting data from V8, using "push" model.
+ */
+class V8_EXPORT OutputStream {  // NOLINT
+ public:
+  enum WriteResult {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~OutputStream() {}
+  /** Notify about the end of stream. */
+  virtual void EndOfStream() = 0;
+  /** Get preferred output chunk size. Called only once. */
+  virtual int GetChunkSize() { return 1024; }
+  /**
+   * Writes the next chunk of snapshot data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteAsciiChunk(char* data, int size) = 0;
+  /**
+   * Writes the next chunk of heap stats data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate* data, int count) {
+    return kAbort;
+  }
+};
+
+
+/**
+ * HeapSnapshots record the state of the JS heap at some moment.
+ */
+class V8_EXPORT HeapSnapshot {
+ public:
+  enum SerializationFormat {
+    kJSON = 0  // See format description near 'Serialize' method.
+  };
+
+  /** Returns the root node of the heap graph. */
+  const HeapGraphNode* GetRoot() const;
+
+  /** Returns a node by its id. */
+  const HeapGraphNode* GetNodeById(SnapshotObjectId id) const;
+
+  /** Returns total nodes count in the snapshot. */
+  int GetNodesCount() const;
+
+  /** Returns a node by index. */
+  const HeapGraphNode* GetNode(int index) const;
+
+  /** Returns a max seen JS object Id. */
+  SnapshotObjectId GetMaxSnapshotJSObjectId() const;
+
+  /**
+   * Deletes the snapshot and removes it from HeapProfiler's list.
+   * All pointers to nodes, edges and paths previously returned become
+   * invalid.
+   */
+  void Delete();
+
+  /**
+   * Prepare a serialized representation of the snapshot. The result
+   * is written into the stream provided in chunks of specified size.
+   * The total length of the serialized snapshot is unknown in
+   * advance, it can be roughly equal to JS heap size (that means,
+   * it can be really big - tens of megabytes).
+   *
+   * For the JSON format, heap contents are represented as an object
+   * with the following structure:
+   *
+   *  {
+   *    snapshot: {
+   *      title: "...",
+   *      uid: nnn,
+   *      meta: { meta-info },
+   *      node_count: nnn,
+   *      edge_count: nnn
+   *    },
+   *    nodes: [nodes array],
+   *    edges: [edges array],
+   *    strings: [strings array]
+   *  }
+   *
+   * Nodes reference strings, other nodes, and edges by their indexes
+   * in corresponding arrays.
+   */
+  void Serialize(OutputStream* stream,
+                 SerializationFormat format = kJSON) const;
+};
+
+
+/**
+ * An interface for reporting progress and controlling long-running
+ * activities.
+ */
+class V8_EXPORT ActivityControl {  // NOLINT
+ public:
+  enum ControlOption {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~ActivityControl() {}
+  /**
+   * Notify about current progress. The activity can be stopped by
+   * returning kAbort as the callback result.
+   */
+  virtual ControlOption ReportProgressValue(int done, int total) = 0;
+};
+
+
+/**
+ * AllocationProfile is a sampled profile of allocations done by the program.
+ * This is structured as a call-graph.
+ */
+class V8_EXPORT AllocationProfile {
+ public:
+  struct Allocation {
+    /**
+     * Size of the sampled allocation object.
+     */
+    size_t size;
+
+    /**
+     * The number of objects of such size that were sampled.
+     */
+    unsigned int count;
+  };
+
+  /**
+   * Represents a node in the call-graph.
+   */
+  struct Node {
+    /**
+     * Name of the function. May be empty for anonymous functions or if the
+     * script corresponding to this function has been unloaded.
+     */
+    Local<String> name;
+
+    /**
+     * Name of the script containing the function. May be empty if the script
+     * name is not available, or if the script has been unloaded.
+     */
+    Local<String> script_name;
+
+    /**
+     * id of the script where the function is located. May be equal to
+     * v8::UnboundScript::kNoScriptId in cases where the script doesn't exist.
+     */
+    int script_id;
+
+    /**
+     * Start position of the function in the script.
+     */
+    int start_position;
+
+    /**
+     * 1-indexed line number where the function starts. May be
+     * kNoLineNumberInfo if no line number information is available.
+     */
+    int line_number;
+
+    /**
+     * 1-indexed column number where the function starts. May be
+     * kNoColumnNumberInfo if no line number information is available.
+     */
+    int column_number;
+
+    /**
+     * List of callees called from this node for which we have sampled
+     * allocations. The lifetime of the children is scoped to the containing
+     * AllocationProfile.
+     */
+    std::vector<Node*> children;
+
+    /**
+     * List of self allocations done by this node in the call-graph.
+     */
+    std::vector<Allocation> allocations;
+  };
+
+  /**
+   * Returns the root node of the call-graph. The root node corresponds to an
+   * empty JS call-stack. The lifetime of the returned Node* is scoped to the
+   * containing AllocationProfile.
+   */
+  virtual Node* GetRootNode() = 0;
+
+  virtual ~AllocationProfile() {}
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * Interface for controlling heap profiling. Instance of the
+ * profiler can be retrieved using v8::Isolate::GetHeapProfiler.
+ */
+class V8_EXPORT HeapProfiler {
+ public:
+  enum SamplingFlags {
+    kSamplingNoFlags = 0,
+    kSamplingForceGC = 1 << 0,
+  };
+
+  typedef std::unordered_set<const v8::PersistentBase<v8::Value>*>
+      RetainerChildren;
+  typedef std::vector<std::pair<v8::RetainedObjectInfo*, RetainerChildren>>
+      RetainerGroups;
+  typedef std::vector<std::pair<const v8::PersistentBase<v8::Value>*,
+                                const v8::PersistentBase<v8::Value>*>>
+      RetainerEdges;
+
+  struct RetainerInfos {
+    RetainerGroups groups;
+    RetainerEdges edges;
+  };
+
+  /**
+   * Callback function invoked to retrieve all RetainerInfos from the embedder.
+   */
+  typedef RetainerInfos (*GetRetainerInfosCallback)(v8::Isolate* isolate);
+
+  /**
+   * Callback function invoked for obtaining RetainedObjectInfo for
+   * the given JavaScript wrapper object. It is prohibited to enter V8
+   * while the callback is running: only getters on the handle and
+   * GetPointerFromInternalField on the objects are allowed.
+   */
+  typedef RetainedObjectInfo* (*WrapperInfoCallback)(uint16_t class_id,
+                                                     Local<Value> wrapper);
+
+  /** Returns the number of snapshots taken. */
+  int GetSnapshotCount();
+
+  /** Returns a snapshot by index. */
+  const HeapSnapshot* GetHeapSnapshot(int index);
+
+  /**
+   * Returns SnapshotObjectId for a heap object referenced by |value| if
+   * it has been seen by the heap profiler, kUnknownObjectId otherwise.
+   */
+  SnapshotObjectId GetObjectId(Local<Value> value);
+
+  /**
+   * Returns heap object with given SnapshotObjectId if the object is alive,
+   * otherwise empty handle is returned.
+   */
+  Local<Value> FindObjectById(SnapshotObjectId id);
+
+  /**
+   * Clears internal map from SnapshotObjectId to heap object. The new objects
+   * will not be added into it unless a heap snapshot is taken or heap object
+   * tracking is kicked off.
+   */
+  void ClearObjectIds();
+
+  /**
+   * A constant for invalid SnapshotObjectId. GetSnapshotObjectId will return
+   * it in case heap profiler cannot find id  for the object passed as
+   * parameter. HeapSnapshot::GetNodeById will always return NULL for such id.
+   */
+  static const SnapshotObjectId kUnknownObjectId = 0;
+
+  /**
+   * Callback interface for retrieving user friendly names of global objects.
+   */
+  class ObjectNameResolver {
+   public:
+    /**
+     * Returns name to be used in the heap snapshot for given node. Returned
+     * string must stay alive until snapshot collection is completed.
+     */
+    virtual const char* GetName(Local<Object> object) = 0;
+
+   protected:
+    virtual ~ObjectNameResolver() {}
+  };
+
+  /**
+   * Takes a heap snapshot and returns it.
+   */
+  const HeapSnapshot* TakeHeapSnapshot(
+      ActivityControl* control = NULL,
+      ObjectNameResolver* global_object_name_resolver = NULL);
+
+  /**
+   * Starts tracking of heap objects population statistics. After calling
+   * this method, all heap objects relocations done by the garbage collector
+   * are being registered.
+   *
+   * |track_allocations| parameter controls whether stack trace of each
+   * allocation in the heap will be recorded and reported as part of
+   * HeapSnapshot.
+   */
+  void StartTrackingHeapObjects(bool track_allocations = false);
+
+  /**
+   * Adds a new time interval entry to the aggregated statistics array. The
+   * time interval entry contains information on the current heap objects
+   * population size. The method also updates aggregated statistics and
+   * reports updates for all previous time intervals via the OutputStream
+   * object. Updates on each time interval are provided as a stream of the
+   * HeapStatsUpdate structure instances.
+   * If |timestamp_us| is supplied, timestamp of the new entry will be written
+   * into it. The return value of the function is the last seen heap object Id.
+   *
+   * StartTrackingHeapObjects must be called before the first call to this
+   * method.
+   */
+  SnapshotObjectId GetHeapStats(OutputStream* stream,
+                                int64_t* timestamp_us = NULL);
+
+  /**
+   * Stops tracking of heap objects population statistics, cleans up all
+   * collected data. StartHeapObjectsTracking must be called again prior to
+   * calling GetHeapStats next time.
+   */
+  void StopTrackingHeapObjects();
+
+  /**
+   * Starts gathering a sampling heap profile. A sampling heap profile is
+   * similar to tcmalloc's heap profiler and Go's mprof. It samples object
+   * allocations and builds an online 'sampling' heap profile. At any point in
+   * time, this profile is expected to be a representative sample of objects
+   * currently live in the system. Each sampled allocation includes the stack
+   * trace at the time of allocation, which makes this really useful for memory
+   * leak detection.
+   *
+   * This mechanism is intended to be cheap enough that it can be used in
+   * production with minimal performance overhead.
+   *
+   * Allocations are sampled using a randomized Poisson process. On average, one
+   * allocation will be sampled every |sample_interval| bytes allocated. The
+   * |stack_depth| parameter controls the maximum number of stack frames to be
+   * captured on each allocation.
+   *
+   * NOTE: This is a proof-of-concept at this point. Right now we only sample
+   * newspace allocations. Support for paged space allocation (e.g. pre-tenured
+   * objects, large objects, code objects, etc.) and native allocations
+   * doesn't exist yet, but is anticipated in the future.
+   *
+   * Objects allocated before the sampling is started will not be included in
+   * the profile.
+   *
+   * Returns false if a sampling heap profiler is already running.
+   */
+  bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024,
+                                 int stack_depth = 16,
+                                 SamplingFlags flags = kSamplingNoFlags);
+
+  /**
+   * Stops the sampling heap profile and discards the current profile.
+   */
+  void StopSamplingHeapProfiler();
+
+  /**
+   * Returns the sampled profile of allocations allocated (and still live) since
+   * StartSamplingHeapProfiler was called. The ownership of the pointer is
+   * transfered to the caller. Returns nullptr if sampling heap profiler is not
+   * active.
+   */
+  AllocationProfile* GetAllocationProfile();
+
+  /**
+   * Deletes all snapshots taken. All previously returned pointers to
+   * snapshots and their contents become invalid after this call.
+   */
+  void DeleteAllHeapSnapshots();
+
+  /** Binds a callback to embedder's class ID. */
+  void SetWrapperClassInfoProvider(
+      uint16_t class_id,
+      WrapperInfoCallback callback);
+
+  void SetGetRetainerInfosCallback(GetRetainerInfosCallback callback);
+
+  /**
+   * Default value of persistent handle class ID. Must not be used to
+   * define a class. Can be used to reset a class of a persistent
+   * handle.
+   */
+  static const uint16_t kPersistentHandleNoClassId = 0;
+
+  /** Returns memory used for profiler internal data and snapshots. */
+  size_t GetProfilerMemorySize();
+
+ private:
+  HeapProfiler();
+  ~HeapProfiler();
+  HeapProfiler(const HeapProfiler&);
+  HeapProfiler& operator=(const HeapProfiler&);
+};
+
+/**
+ * Interface for providing information about embedder's objects
+ * held by global handles. This information is reported in two ways:
+ *
+ *  1. When calling AddObjectGroup, an embedder may pass
+ *     RetainedObjectInfo instance describing the group.  To collect
+ *     this information while taking a heap snapshot, V8 calls GC
+ *     prologue and epilogue callbacks.
+ *
+ *  2. When a heap snapshot is collected, V8 additionally
+ *     requests RetainedObjectInfos for persistent handles that
+ *     were not previously reported via AddObjectGroup.
+ *
+ * Thus, if an embedder wants to provide information about native
+ * objects for heap snapshots, it can do it in a GC prologue
+ * handler, and / or by assigning wrapper class ids in the following way:
+ *
+ *  1. Bind a callback to class id by calling SetWrapperClassInfoProvider.
+ *  2. Call SetWrapperClassId on certain persistent handles.
+ *
+ * V8 takes ownership of RetainedObjectInfo instances passed to it and
+ * keeps them alive only during snapshot collection. Afterwards, they
+ * are freed by calling the Dispose class function.
+ */
+class V8_EXPORT RetainedObjectInfo {  // NOLINT
+ public:
+  /** Called by V8 when it no longer needs an instance. */
+  virtual void Dispose() = 0;
+
+  /** Returns whether two instances are equivalent. */
+  virtual bool IsEquivalent(RetainedObjectInfo* other) = 0;
+
+  /**
+   * Returns hash value for the instance. Equivalent instances
+   * must have the same hash value.
+   */
+  virtual intptr_t GetHash() = 0;
+
+  /**
+   * Returns human-readable label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetLabel.
+   */
+  virtual const char* GetLabel() = 0;
+
+  /**
+   * Returns human-readable group label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetGroupLabel.
+   * Heap snapshot generator will collect all the group names, create
+   * top level entries with these names and attach the objects to the
+   * corresponding top level group objects. There is a default
+   * implementation which is required because embedders don't have their
+   * own implementation yet.
+   */
+  virtual const char* GetGroupLabel() { return GetLabel(); }
+
+  /**
+   * Returns element count in case if a global handle retains
+   * a subgraph by holding one of its nodes.
+   */
+  virtual intptr_t GetElementCount() { return -1; }
+
+  /** Returns embedder's object size in bytes. */
+  virtual intptr_t GetSizeInBytes() { return -1; }
+
+ protected:
+  RetainedObjectInfo() {}
+  virtual ~RetainedObjectInfo() {}
+
+ private:
+  RetainedObjectInfo(const RetainedObjectInfo&);
+  RetainedObjectInfo& operator=(const RetainedObjectInfo&);
+};
+
+
+/**
+ * A struct for exporting HeapStats data from V8, using "push" model.
+ * See HeapProfiler::GetHeapStats.
+ */
+struct HeapStatsUpdate {
+  HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size)
+    : index(index), count(count), size(size) { }
+  uint32_t index;  // Index of the time interval that was changed.
+  uint32_t count;  // New value of count field for the interval with this index.
+  uint32_t size;  // New value of size field for the interval with this index.
+};
+
+
+}  // namespace v8
+
+
+#endif  // V8_V8_PROFILER_H_
diff --git a/android/arm64-v8a/include/v8/v8-testing.h b/android/arm64-v8a/include/v8/v8-testing.h
new file mode 100644
index 00000000..f67bf253
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-testing.h
@@ -0,0 +1,48 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_TEST_H_
+#define V8_V8_TEST_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Testing support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class V8_EXPORT Testing {
+ public:
+  enum StressType {
+    kStressTypeOpt,
+    kStressTypeDeopt
+  };
+
+  /**
+   * Set the type of stressing to do. The default if not set is kStressTypeOpt.
+   */
+  static void SetStressRunType(StressType type);
+
+  /**
+   * Get the number of runs of a given test that is required to get the full
+   * stress coverage.
+   */
+  static int GetStressRuns();
+
+  /**
+   * Indicate the number of the run which is about to start. The value of run
+   * should be between 0 and one less than the result from GetStressRuns()
+   */
+  static void PrepareStressRun(int run);
+
+  /**
+   * Force deoptimization of all functions.
+   */
+  static void DeoptimizeAll(Isolate* isolate);
+};
+
+
+}  // namespace v8
+
+#endif  // V8_V8_TEST_H_
diff --git a/android/arm64-v8a/include/v8/v8-util.h b/android/arm64-v8a/include/v8/v8-util.h
new file mode 100644
index 00000000..a04a5e84
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-util.h
@@ -0,0 +1,655 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_UTIL_H_
+#define V8_UTIL_H_
+
+#include "v8.h"  // NOLINT(build/include)
+#include <assert.h>
+#include <map>
+#include <vector>
+
+/**
+ * Support for Persistent containers.
+ *
+ * C++11 embedders can use STL containers with Global values,
+ * but pre-C++11 does not support the required move semantic and hence
+ * may want these container classes.
+ */
+namespace v8 {
+
+typedef uintptr_t PersistentContainerValue;
+static const uintptr_t kPersistentContainerNotFound = 0;
+enum PersistentContainerCallbackType {
+  kNotWeak,
+  // These correspond to v8::WeakCallbackType
+  kWeakWithParameter,
+  kWeakWithInternalFields,
+  kWeak = kWeakWithParameter  // For backwards compatibility.  Deprecate.
+};
+
+
+/**
+ * A default trait implemenation for PersistentValueMap which uses std::map
+ * as a backing map.
+ *
+ * Users will have to implement their own weak callbacks & dispose traits.
+ */
+template<typename K, typename V>
+class StdMapTraits {
+ public:
+  // STL map & related:
+  typedef std::map<K, PersistentContainerValue> Impl;
+  typedef typename Impl::iterator Iterator;
+
+  static bool Empty(Impl* impl) { return impl->empty(); }
+  static size_t Size(Impl* impl) { return impl->size(); }
+  static void Swap(Impl& a, Impl& b) { std::swap(a, b); }  // NOLINT
+  static Iterator Begin(Impl* impl) { return impl->begin(); }
+  static Iterator End(Impl* impl) { return impl->end(); }
+  static K Key(Iterator it) { return it->first; }
+  static PersistentContainerValue Value(Iterator it) { return it->second; }
+  static PersistentContainerValue Set(Impl* impl, K key,
+      PersistentContainerValue value) {
+    std::pair<Iterator, bool> res = impl->insert(std::make_pair(key, value));
+    PersistentContainerValue old_value = kPersistentContainerNotFound;
+    if (!res.second) {
+      old_value = res.first->second;
+      res.first->second = value;
+    }
+    return old_value;
+  }
+  static PersistentContainerValue Get(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    return it->second;
+  }
+  static PersistentContainerValue Remove(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    PersistentContainerValue value = it->second;
+    impl->erase(it);
+    return value;
+  }
+};
+
+
+/**
+ * A default trait implementation for PersistentValueMap, which inherits
+ * a std:map backing map from StdMapTraits and holds non-weak persistent
+ * objects and has no special Dispose handling.
+ *
+ * You should not derive from this class, since MapType depends on the
+ * surrounding class, and hence a subclass cannot simply inherit the methods.
+ */
+template<typename K, typename V>
+class DefaultPersistentValueMapTraits : public StdMapTraits<K, V> {
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef PersistentValueMap<K, V, DefaultPersistentValueMapTraits<K, V> >
+      MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(
+      MapType* map, const K& key, Local<V> value) {
+    return NULL;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return NULL;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) { }
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+};
+
+
+template <typename K, typename V>
+class DefaultGlobalMapTraits : public StdMapTraits<K, V> {
+ private:
+  template <typename T>
+  struct RemovePointer;
+
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef GlobalValueMap<K, V, DefaultGlobalMapTraits<K, V> > MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(MapType* map, const K& key,
+                                                     Local<V> value) {
+    return nullptr;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return nullptr;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) {}
+  static void OnWeakCallback(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+  // This is a second pass callback, so SetSecondPassCallback cannot be called.
+  static void DisposeWeak(const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+
+ private:
+  template <typename T>
+  struct RemovePointer<T*> {
+    typedef T Type;
+  };
+};
+
+
+/**
+ * A map wrapper that allows using Global as a mapped value.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * The map relies on a backing map, whose type and accessors are described
+ * by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template <typename K, typename V, typename Traits>
+class PersistentValueMapBase {
+ public:
+  Isolate* GetIsolate() { return isolate_; }
+
+  /**
+   * Return size of the map.
+   */
+  size_t Size() { return Traits::Size(&impl_); }
+
+  /**
+   * Return whether the map holds weak persistents.
+   */
+  bool IsWeak() { return Traits::kCallbackType != kNotWeak; }
+
+  /**
+   * Get value stored in map.
+   */
+  Local<V> Get(const K& key) {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, key)));
+  }
+
+  /**
+   * Check whether a value is contained in the map.
+   */
+  bool Contains(const K& key) {
+    return Traits::Get(&impl_, key) != kPersistentContainerNotFound;
+  }
+
+  /**
+   * Get value stored in map and set it in returnValue.
+   * Return true if a value was found.
+   */
+  bool SetReturnValue(const K& key,
+      ReturnValue<Value> returnValue) {
+    return SetReturnValueFromVal(&returnValue, Traits::Get(&impl_, key));
+  }
+
+  /**
+   * Call Isolate::SetReference with the given parent and the map value.
+   */
+  void SetReference(const K& key,
+      const Persistent<Object>& parent) {
+    GetIsolate()->SetReference(
+      reinterpret_cast<internal::Object**>(parent.val_),
+      reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))));
+  }
+
+  /**
+   * Call V8::RegisterExternallyReferencedObject with the map value for given
+   * key.
+   */
+  void RegisterExternallyReferencedObject(K& key) {
+    assert(Contains(key));
+    V8::RegisterExternallyReferencedObject(
+        reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))),
+        reinterpret_cast<internal::Isolate*>(GetIsolate()));
+  }
+
+  /**
+   * Return value for key and remove it from the map.
+   */
+  Global<V> Remove(const K& key) {
+    return Release(Traits::Remove(&impl_, key)).Pass();
+  }
+
+  /**
+  * Traverses the map repeatedly,
+  * in case side effects of disposal cause insertions.
+  **/
+  void Clear() {
+    typedef typename Traits::Iterator It;
+    HandleScope handle_scope(isolate_);
+    // TODO(dcarney): figure out if this swap and loop is necessary.
+    while (!Traits::Empty(&impl_)) {
+      typename Traits::Impl impl;
+      Traits::Swap(impl_, impl);
+      for (It i = Traits::Begin(&impl); i != Traits::End(&impl); ++i) {
+        Traits::Dispose(isolate_, Release(Traits::Value(i)).Pass(),
+                        Traits::Key(i));
+      }
+    }
+  }
+
+  /**
+   * Helper class for GetReference/SetWithReference. Do not use outside
+   * that context.
+   */
+  class PersistentValueReference {
+   public:
+    PersistentValueReference() : value_(kPersistentContainerNotFound) { }
+    PersistentValueReference(const PersistentValueReference& other)
+        : value_(other.value_) { }
+
+    Local<V> NewLocal(Isolate* isolate) const {
+      return Local<V>::New(isolate, FromVal(value_));
+    }
+    bool IsEmpty() const {
+      return value_ == kPersistentContainerNotFound;
+    }
+    template<typename T>
+    bool SetReturnValue(ReturnValue<T> returnValue) {
+      return SetReturnValueFromVal(&returnValue, value_);
+    }
+    void Reset() {
+      value_ = kPersistentContainerNotFound;
+    }
+    void operator=(const PersistentValueReference& other) {
+      value_ = other.value_;
+    }
+
+   private:
+    friend class PersistentValueMapBase;
+    friend class PersistentValueMap<K, V, Traits>;
+    friend class GlobalValueMap<K, V, Traits>;
+
+    explicit PersistentValueReference(PersistentContainerValue value)
+        : value_(value) { }
+
+    void operator=(PersistentContainerValue value) {
+      value_ = value;
+    }
+
+    PersistentContainerValue value_;
+  };
+
+  /**
+   * Get a reference to a map value. This enables fast, repeated access
+   * to a value stored in the map while the map remains unchanged.
+   *
+   * Careful: This is potentially unsafe, so please use with care.
+   * The value will become invalid if the value for this key changes
+   * in the underlying map, as a result of Set or Remove for the same
+   * key; as a result of the weak callback for the same key; or as a
+   * result of calling Clear() or destruction of the map.
+   */
+  PersistentValueReference GetReference(const K& key) {
+    return PersistentValueReference(Traits::Get(&impl_, key));
+  }
+
+ protected:
+  explicit PersistentValueMapBase(Isolate* isolate) : isolate_(isolate) {}
+
+  ~PersistentValueMapBase() { Clear(); }
+
+  Isolate* isolate() { return isolate_; }
+  typename Traits::Impl* impl() { return &impl_; }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static PersistentContainerValue Leak(Global<V>* persistent) {
+    return reinterpret_cast<PersistentContainerValue>(persistent->val_);
+  }
+
+  /**
+   * Return a container value as Global and make sure the weak
+   * callback is properly disposed of. All remove functionality should go
+   * through this.
+   */
+  static Global<V> Release(PersistentContainerValue v) {
+    Global<V> p;
+    p.val_ = FromVal(v);
+    if (Traits::kCallbackType != kNotWeak && p.IsWeak()) {
+      Traits::DisposeCallbackData(
+          p.template ClearWeak<typename Traits::WeakCallbackDataType>());
+    }
+    return p.Pass();
+  }
+
+  void RemoveWeak(const K& key) {
+    Global<V> p;
+    p.val_ = FromVal(Traits::Remove(&impl_, key));
+    p.Reset();
+  }
+
+ private:
+  PersistentValueMapBase(PersistentValueMapBase&);
+  void operator=(PersistentValueMapBase&);
+
+  static bool SetReturnValueFromVal(ReturnValue<Value>* returnValue,
+                                    PersistentContainerValue value) {
+    bool hasValue = value != kPersistentContainerNotFound;
+    if (hasValue) {
+      returnValue->SetInternal(
+          *reinterpret_cast<internal::Object**>(FromVal(value)));
+    }
+    return hasValue;
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+
+template <typename K, typename V, typename Traits>
+class PersistentValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit PersistentValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+        Traits::WeakCallbackParameter(this, key, value), WeakCallback);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void WeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      PersistentValueMap<K, V, Traits>* persistentValueMap =
+          Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      Traits::Dispose(data.GetIsolate(),
+                      persistentValueMap->Remove(key).Pass(), key);
+      Traits::DisposeCallbackData(data.GetParameter());
+    }
+  }
+};
+
+
+template <typename K, typename V, typename Traits>
+class GlobalValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit GlobalValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      WeakCallbackType callback_type =
+          Traits::kCallbackType == kWeakWithInternalFields
+              ? WeakCallbackType::kInternalFields
+              : WeakCallbackType::kParameter;
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+          Traits::WeakCallbackParameter(this, key, value), OnWeakCallback,
+          callback_type);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void OnWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      auto map = Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      map->RemoveWeak(key);
+      Traits::OnWeakCallback(data);
+      data.SetSecondPassCallback(SecondWeakCallback);
+    }
+  }
+
+  static void SecondWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    Traits::DisposeWeak(data);
+  }
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Persistents are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template<typename K, typename V,
+    typename Traits = DefaultPersistentValueMapTraits<K, V> >
+class StdPersistentValueMap : public PersistentValueMap<K, V, Traits> {
+ public:
+  explicit StdPersistentValueMap(Isolate* isolate)
+      : PersistentValueMap<K, V, Traits>(isolate) {}
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Globals are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template <typename K, typename V,
+          typename Traits = DefaultGlobalMapTraits<K, V> >
+class StdGlobalValueMap : public GlobalValueMap<K, V, Traits> {
+ public:
+  explicit StdGlobalValueMap(Isolate* isolate)
+      : GlobalValueMap<K, V, Traits>(isolate) {}
+};
+
+
+class DefaultPersistentValueVectorTraits {
+ public:
+  typedef std::vector<PersistentContainerValue> Impl;
+
+  static void Append(Impl* impl, PersistentContainerValue value) {
+    impl->push_back(value);
+  }
+  static bool IsEmpty(const Impl* impl) {
+    return impl->empty();
+  }
+  static size_t Size(const Impl* impl) {
+    return impl->size();
+  }
+  static PersistentContainerValue Get(const Impl* impl, size_t i) {
+    return (i < impl->size()) ? impl->at(i) : kPersistentContainerNotFound;
+  }
+  static void ReserveCapacity(Impl* impl, size_t capacity) {
+    impl->reserve(capacity);
+  }
+  static void Clear(Impl* impl) {
+    impl->clear();
+  }
+};
+
+
+/**
+ * A vector wrapper that safely stores Global values.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * This class relies on a backing vector implementation, whose type and methods
+ * are described by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template<typename V, typename Traits = DefaultPersistentValueVectorTraits>
+class PersistentValueVector {
+ public:
+  explicit PersistentValueVector(Isolate* isolate) : isolate_(isolate) { }
+
+  ~PersistentValueVector() {
+    Clear();
+  }
+
+  /**
+   * Append a value to the vector.
+   */
+  void Append(Local<V> value) {
+    Global<V> persistent(isolate_, value);
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Append a persistent's value to the vector.
+   */
+  void Append(Global<V> persistent) {
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Are there any values in the vector?
+   */
+  bool IsEmpty() const {
+    return Traits::IsEmpty(&impl_);
+  }
+
+  /**
+   * How many elements are in the vector?
+   */
+  size_t Size() const {
+    return Traits::Size(&impl_);
+  }
+
+  /**
+   * Retrieve the i-th value in the vector.
+   */
+  Local<V> Get(size_t index) const {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, index)));
+  }
+
+  /**
+   * Remove all elements from the vector.
+   */
+  void Clear() {
+    size_t length = Traits::Size(&impl_);
+    for (size_t i = 0; i < length; i++) {
+      Global<V> p;
+      p.val_ = FromVal(Traits::Get(&impl_, i));
+    }
+    Traits::Clear(&impl_);
+  }
+
+  /**
+   * Reserve capacity in the vector.
+   * (Efficiency gains depend on the backing implementation.)
+   */
+  void ReserveCapacity(size_t capacity) {
+    Traits::ReserveCapacity(&impl_, capacity);
+  }
+
+ private:
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+}  // namespace v8
+
+#endif  // V8_UTIL_H
diff --git a/android/arm64-v8a/include/v8/v8-value-serializer-version.h b/android/arm64-v8a/include/v8/v8-value-serializer-version.h
new file mode 100644
index 00000000..c72911c6
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-value-serializer-version.h
@@ -0,0 +1,24 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Compile-time constants.
+ *
+ * This header provides access to information about the value serializer at
+ * compile time, without declaring or defining any symbols that require linking
+ * to V8.
+ */
+
+#ifndef INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+#define INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+
+#include <stdint.h>
+
+namespace v8 {
+
+constexpr uint32_t CurrentValueSerializerFormatVersion() { return 13; }
+
+}  // namespace v8
+
+#endif  // INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
diff --git a/android/arm64-v8a/include/v8/v8-version-string.h b/android/arm64-v8a/include/v8/v8-version-string.h
new file mode 100644
index 00000000..075282de
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-version-string.h
@@ -0,0 +1,33 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_VERSION_STRING_H_
+#define V8_VERSION_STRING_H_
+
+#include "v8-version.h"  // NOLINT(build/include)
+
+// This is here rather than v8-version.h to keep that file simple and
+// machine-processable.
+
+#if V8_IS_CANDIDATE_VERSION
+#define V8_CANDIDATE_STRING " (candidate)"
+#else
+#define V8_CANDIDATE_STRING ""
+#endif
+
+#define V8_SX(x) #x
+#define V8_S(x) V8_SX(x)
+
+#if V8_PATCH_LEVEL > 0
+#define V8_VERSION_STRING                                        \
+  V8_S(V8_MAJOR_VERSION)                                         \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) "." V8_S( \
+      V8_PATCH_LEVEL) V8_CANDIDATE_STRING
+#else
+#define V8_VERSION_STRING \
+  V8_S(V8_MAJOR_VERSION)  \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) V8_CANDIDATE_STRING
+#endif
+
+#endif  // V8_VERSION_STRING_H_
diff --git a/android/arm64-v8a/include/v8/v8-version.h b/android/arm64-v8a/include/v8/v8-version.h
new file mode 100644
index 00000000..0889459c
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8-version.h
@@ -0,0 +1,20 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INCLUDE_VERSION_H_  // V8_VERSION_H_ conflicts with src/version.h
+#define V8_INCLUDE_VERSION_H_
+
+// These macros define the version number for the current version.
+// NOTE these macros are used by some of the tool scripts and the build
+// system so their names cannot be changed without changing the scripts.
+#define V8_MAJOR_VERSION 6
+#define V8_MINOR_VERSION 0
+#define V8_BUILD_NUMBER 286
+#define V8_PATCH_LEVEL 52
+
+// Use 1 for candidates and 0 otherwise.
+// (Boolean macro values are not supported by all preprocessors.)
+#define V8_IS_CANDIDATE_VERSION 0
+
+#endif  // V8_INCLUDE_VERSION_H_
diff --git a/android/arm64-v8a/include/v8/v8.h b/android/arm64-v8a/include/v8/v8.h
new file mode 100644
index 00000000..da3cdfdc
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8.h
@@ -0,0 +1,10155 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/** \mainpage V8 API Reference Guide
+ *
+ * V8 is Google's open source JavaScript engine.
+ *
+ * This set of documents provides reference material generated from the
+ * V8 header file, include/v8.h.
+ *
+ * For other documentation see http://code.google.com/apis/v8/
+ */
+
+#ifndef INCLUDE_V8_H_
+#define INCLUDE_V8_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "v8-version.h"  // NOLINT(build/include)
+#include "v8config.h"    // NOLINT(build/include)
+
+// We reserve the V8_* prefix for macros defined in V8 public API and
+// assume there are no name conflicts with the embedder's code.
+
+#ifdef V8_OS_WIN
+
+// Setup for Windows DLL export/import. When building the V8 DLL the
+// BUILDING_V8_SHARED needs to be defined. When building a program which uses
+// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
+// static library or building a program which uses the V8 static library neither
+// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
+#ifdef BUILDING_V8_SHARED
+# define V8_EXPORT __declspec(dllexport)
+#elif USING_V8_SHARED
+# define V8_EXPORT __declspec(dllimport)
+#else
+# define V8_EXPORT
+#endif  // BUILDING_V8_SHARED
+
+#else  // V8_OS_WIN
+
+// Setup for Linux shared library export.
+#if V8_HAS_ATTRIBUTE_VISIBILITY
+# ifdef BUILDING_V8_SHARED
+#  define V8_EXPORT __attribute__ ((visibility("default")))
+# else
+#  define V8_EXPORT
+# endif
+#else
+# define V8_EXPORT
+#endif
+
+#endif  // V8_OS_WIN
+
+/**
+ * The v8 JavaScript engine.
+ */
+namespace v8 {
+
+class AccessorSignature;
+class Array;
+class ArrayBuffer;
+class Boolean;
+class BooleanObject;
+class Context;
+class CpuProfiler;
+class Data;
+class Date;
+class External;
+class Function;
+class FunctionTemplate;
+class HeapProfiler;
+class ImplementationUtilities;
+class Int32;
+class Integer;
+class Isolate;
+template <class T>
+class Maybe;
+class Name;
+class Number;
+class NumberObject;
+class Object;
+class ObjectOperationDescriptor;
+class ObjectTemplate;
+class Platform;
+class Primitive;
+class Promise;
+class PropertyDescriptor;
+class Proxy;
+class RawOperationDescriptor;
+class Script;
+class SharedArrayBuffer;
+class Signature;
+class StartupData;
+class StackFrame;
+class StackTrace;
+class String;
+class StringObject;
+class Symbol;
+class SymbolObject;
+class Private;
+class Uint32;
+class Utils;
+class Value;
+class WasmCompiledModule;
+template <class T> class Local;
+template <class T>
+class MaybeLocal;
+template <class T> class Eternal;
+template<class T> class NonCopyablePersistentTraits;
+template<class T> class PersistentBase;
+template <class T, class M = NonCopyablePersistentTraits<T> >
+class Persistent;
+template <class T>
+class Global;
+template<class K, class V, class T> class PersistentValueMap;
+template <class K, class V, class T>
+class PersistentValueMapBase;
+template <class K, class V, class T>
+class GlobalValueMap;
+template<class V, class T> class PersistentValueVector;
+template<class T, class P> class WeakCallbackObject;
+class FunctionTemplate;
+class ObjectTemplate;
+template<typename T> class FunctionCallbackInfo;
+template<typename T> class PropertyCallbackInfo;
+class StackTrace;
+class StackFrame;
+class Isolate;
+class CallHandlerHelper;
+class EscapableHandleScope;
+template<typename T> class ReturnValue;
+
+namespace internal {
+class Arguments;
+class Heap;
+class HeapObject;
+class Isolate;
+class Object;
+struct StreamedSource;
+template<typename T> class CustomArguments;
+class PropertyCallbackArguments;
+class FunctionCallbackArguments;
+class GlobalHandles;
+}  // namespace internal
+
+namespace debug {
+class ConsoleCallArguments;
+}  // namespace debug
+
+// --- Handles ---
+
+#define TYPE_CHECK(T, S)                                       \
+  while (false) {                                              \
+    *(static_cast<T* volatile*>(0)) = static_cast<S*>(0);      \
+  }
+
+/**
+ * An object reference managed by the v8 garbage collector.
+ *
+ * All objects returned from v8 have to be tracked by the garbage
+ * collector so that it knows that the objects are still alive.  Also,
+ * because the garbage collector may move objects, it is unsafe to
+ * point directly to an object.  Instead, all objects are stored in
+ * handles which are known by the garbage collector and updated
+ * whenever an object moves.  Handles should always be passed by value
+ * (except in cases like out-parameters) and they should never be
+ * allocated on the heap.
+ *
+ * There are two types of handles: local and persistent handles.
+ *
+ * Local handles are light-weight and transient and typically used in
+ * local operations.  They are managed by HandleScopes. That means that a
+ * HandleScope must exist on the stack when they are created and that they are
+ * only valid inside of the HandleScope active during their creation.
+ * For passing a local handle to an outer HandleScope, an EscapableHandleScope
+ * and its Escape() method must be used.
+ *
+ * Persistent handles can be used when storing objects across several
+ * independent operations and have to be explicitly deallocated when they're no
+ * longer used.
+ *
+ * It is safe to extract the object stored in the handle by
+ * dereferencing the handle (for instance, to extract the Object* from
+ * a Local<Object>); the value will still be governed by a handle
+ * behind the scenes and the same rules apply to these values as to
+ * their handles.
+ */
+template <class T>
+class Local {
+ public:
+  V8_INLINE Local() : val_(0) {}
+  template <class S>
+  V8_INLINE Local(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    /**
+     * This check fails when trying to convert between incompatible
+     * handles. For example, converting from a Local<String> to a
+     * Local<Number>.
+     */
+    TYPE_CHECK(T, S);
+  }
+
+  /**
+   * Returns true if the handle is empty.
+   */
+  V8_INLINE bool IsEmpty() const { return val_ == 0; }
+
+  /**
+   * Sets the handle to be empty. IsEmpty() will then return true.
+   */
+  V8_INLINE void Clear() { val_ = 0; }
+
+  V8_INLINE T* operator->() const { return val_; }
+
+  V8_INLINE T* operator*() const { return val_; }
+
+  /**
+   * Checks whether two handles are the same.
+   * Returns true if both are empty, or if the objects
+   * to which they refer are identical.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  template <class S> V8_INLINE bool operator==(
+      const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  /**
+   * Checks whether two handles are different.
+   * Returns true if only one of the handles is empty, or if
+   * the objects to which they refer are different.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S> V8_INLINE bool operator!=(
+      const Persistent<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   * Cast a handle to a subclass, e.g. Local<Value> to Local<Object>.
+   * This is only valid if the handle actually refers to a value of the
+   * target type.
+   */
+  template <class S> V8_INLINE static Local<T> Cast(Local<S> that) {
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (that.IsEmpty()) return Local<T>();
+#endif
+    return Local<T>(T::Cast(*that));
+  }
+
+  /**
+   * Calling this is equivalent to Local<S>::Cast().
+   * In particular, this is only valid if the handle actually refers to a value
+   * of the target type.
+   */
+  template <class S>
+  V8_INLINE Local<S> As() const {
+    return Local<S>::Cast(*this);
+  }
+
+  /**
+   * Create a local handle for the content of another handle.
+   * The referee is kept alive by the local handle even when
+   * the original handle is destroyed/disposed.
+   */
+  V8_INLINE static Local<T> New(Isolate* isolate, Local<T> that);
+  V8_INLINE static Local<T> New(Isolate* isolate,
+                                const PersistentBase<T>& that);
+
+ private:
+  friend class Utils;
+  template<class F> friend class Eternal;
+  template<class F> friend class PersistentBase;
+  template<class F, class M> friend class Persistent;
+  template<class F> friend class Local;
+  template <class F>
+  friend class MaybeLocal;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  friend class String;
+  friend class Object;
+  friend class Context;
+  friend class Private;
+  template<class F> friend class internal::CustomArguments;
+  friend Local<Primitive> Undefined(Isolate* isolate);
+  friend Local<Primitive> Null(Isolate* isolate);
+  friend Local<Boolean> True(Isolate* isolate);
+  friend Local<Boolean> False(Isolate* isolate);
+  friend class HandleScope;
+  friend class EscapableHandleScope;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  template <class F>
+  friend class ReturnValue;
+
+  explicit V8_INLINE Local(T* that) : val_(that) {}
+  V8_INLINE static Local<T> New(Isolate* isolate, T* that);
+  T* val_;
+};
+
+
+#if !defined(V8_IMMINENT_DEPRECATION_WARNINGS)
+// Handle is an alias for Local for historical reasons.
+template <class T>
+using Handle = Local<T>;
+#endif
+
+
+/**
+ * A MaybeLocal<> is a wrapper around Local<> that enforces a check whether
+ * the Local<> is empty before it can be used.
+ *
+ * If an API method returns a MaybeLocal<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, an
+ * empty MaybeLocal is returned.
+ */
+template <class T>
+class MaybeLocal {
+ public:
+  V8_INLINE MaybeLocal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE MaybeLocal(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    TYPE_CHECK(T, S);
+  }
+
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * |false| is returned and |out| is left untouched.
+   */
+  template <class S>
+  V8_WARN_UNUSED_RESULT V8_INLINE bool ToLocal(Local<S>* out) const {
+    out->val_ = IsEmpty() ? nullptr : this->val_;
+    return !IsEmpty();
+  }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * V8 will crash the process.
+   */
+  V8_INLINE Local<T> ToLocalChecked();
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>, using a default value if this
+   * MaybeLocal<> is empty.
+   */
+  template <class S>
+  V8_INLINE Local<S> FromMaybe(Local<S> default_value) const {
+    return IsEmpty() ? default_value : Local<S>(val_);
+  }
+
+ private:
+  T* val_;
+};
+
+/**
+ * Eternal handles are set-once handles that live for the lifetime of the
+ * isolate.
+ */
+template <class T> class Eternal {
+ public:
+  V8_INLINE Eternal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE Eternal(Isolate* isolate, Local<S> handle) : val_(nullptr) {
+    Set(isolate, handle);
+  }
+  // Can only be safely called if already set.
+  V8_INLINE Local<T> Get(Isolate* isolate) const;
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+  template<class S> V8_INLINE void Set(Isolate* isolate, Local<S> handle);
+
+ private:
+  T* val_;
+};
+
+
+static const int kInternalFieldsInWeakCallback = 2;
+static const int kEmbedderFieldsInWeakCallback = 2;
+
+template <typename T>
+class WeakCallbackInfo {
+ public:
+  typedef void (*Callback)(const WeakCallbackInfo<T>& data);
+
+  WeakCallbackInfo(Isolate* isolate, T* parameter,
+                   void* embedder_fields[kEmbedderFieldsInWeakCallback],
+                   Callback* callback)
+      : isolate_(isolate), parameter_(parameter), callback_(callback) {
+    for (int i = 0; i < kEmbedderFieldsInWeakCallback; ++i) {
+      embedder_fields_[i] = embedder_fields[i];
+    }
+  }
+
+  V8_INLINE Isolate* GetIsolate() const { return isolate_; }
+  V8_INLINE T* GetParameter() const { return parameter_; }
+  V8_INLINE void* GetInternalField(int index) const;
+
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField1() const) {
+    return embedder_fields_[0];
+  }
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField2() const) {
+    return embedder_fields_[1];
+  }
+
+  V8_DEPRECATED("Not realiable once SetSecondPassCallback() was used.",
+                bool IsFirstPass() const) {
+    return callback_ != nullptr;
+  }
+
+  // When first called, the embedder MUST Reset() the Global which triggered the
+  // callback. The Global itself is unusable for anything else. No v8 other api
+  // calls may be called in the first callback. Should additional work be
+  // required, the embedder must set a second pass callback, which will be
+  // called after all the initial callbacks are processed.
+  // Calling SetSecondPassCallback on the second pass will immediately crash.
+  void SetSecondPassCallback(Callback callback) const { *callback_ = callback; }
+
+ private:
+  Isolate* isolate_;
+  T* parameter_;
+  Callback* callback_;
+  void* embedder_fields_[kEmbedderFieldsInWeakCallback];
+};
+
+
+// kParameter will pass a void* parameter back to the callback, kInternalFields
+// will pass the first two internal fields back to the callback, kFinalizer
+// will pass a void* parameter back, but is invoked before the object is
+// actually collected, so it can be resurrected. In the last case, it is not
+// possible to request a second pass callback.
+enum class WeakCallbackType { kParameter, kInternalFields, kFinalizer };
+
+/**
+ * An object reference that is independent of any handle scope.  Where
+ * a Local handle only lives as long as the HandleScope in which it was
+ * allocated, a PersistentBase handle remains valid until it is explicitly
+ * disposed using Reset().
+ *
+ * A persistent handle contains a reference to a storage cell within
+ * the V8 engine which holds an object value and which is updated by
+ * the garbage collector whenever the object is moved.  A new storage
+ * cell can be created using the constructor or PersistentBase::Reset and
+ * existing handles can be disposed using PersistentBase::Reset.
+ *
+ */
+template <class T> class PersistentBase {
+ public:
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * IsEmpty() will return true after this call.
+   */
+  V8_INLINE void Reset();
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const Local<S>& other);
+
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const PersistentBase<S>& other);
+
+  V8_INLINE bool IsEmpty() const { return val_ == NULL; }
+  V8_INLINE void Empty() { val_ = 0; }
+
+  V8_INLINE Local<T> Get(Isolate* isolate) const {
+    return Local<T>::New(isolate, *this);
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const PersistentBase<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   *  Install a finalization callback on this object.
+   *  NOTE: There is no guarantee as to *when* or even *if* the callback is
+   *  invoked. The invocation is performed solely on a best effort basis.
+   *  As always, GC-based finalization should *not* be relied upon for any
+   *  critical form of resource management!
+   */
+  template <typename P>
+  V8_INLINE void SetWeak(P* parameter,
+                         typename WeakCallbackInfo<P>::Callback callback,
+                         WeakCallbackType type);
+
+  /**
+   * Turns this handle into a weak phantom handle without finalization callback.
+   * The handle will be reset automatically when the garbage collector detects
+   * that the object is no longer reachable.
+   * A related function Isolate::NumberOfPhantomHandleResetsSinceLastCall
+   * returns how many phantom handles were reset by the garbage collector.
+   */
+  V8_INLINE void SetWeak();
+
+  template<typename P>
+  V8_INLINE P* ClearWeak();
+
+  // TODO(dcarney): remove this.
+  V8_INLINE void ClearWeak() { ClearWeak<void>(); }
+
+  /**
+   * Allows the embedder to tell the v8 garbage collector that a certain object
+   * is alive. Only allowed when the embedder is asked to trace its heap by
+   * EmbedderHeapTracer.
+   */
+  V8_INLINE void RegisterExternalReference(Isolate* isolate) const;
+
+  /**
+   * Marks the reference to this object independent. Garbage collector is free
+   * to ignore any object groups containing this object. Weak callback for an
+   * independent handle should not assume that it will be preceded by a global
+   * GC prologue callback or followed by a global GC epilogue callback.
+   */
+  V8_INLINE void MarkIndependent();
+
+  /**
+   * Marks the reference to this object as active. The scavenge garbage
+   * collection should not reclaim the objects marked as active.
+   * This bit is cleared after the each garbage collection pass.
+   */
+  V8_INLINE void MarkActive();
+
+  V8_INLINE bool IsIndependent() const;
+
+  /** Checks if the handle holds the only reference to an object. */
+  V8_INLINE bool IsNearDeath() const;
+
+  /** Returns true if the handle's reference is weak.  */
+  V8_INLINE bool IsWeak() const;
+
+  /**
+   * Assigns a wrapper class ID to the handle. See RetainedObjectInfo interface
+   * description in v8-profiler.h for details.
+   */
+  V8_INLINE void SetWrapperClassId(uint16_t class_id);
+
+  /**
+   * Returns the class ID previously assigned to this handle or 0 if no class ID
+   * was previously assigned.
+   */
+  V8_INLINE uint16_t WrapperClassId() const;
+
+  PersistentBase(const PersistentBase& other) = delete;  // NOLINT
+  void operator=(const PersistentBase&) = delete;
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template <class F>
+  friend class Global;
+  template<class F> friend class PersistentBase;
+  template<class F> friend class ReturnValue;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  friend class Object;
+
+  explicit V8_INLINE PersistentBase(T* val) : val_(val) {}
+  V8_INLINE static T* New(Isolate* isolate, T* that);
+
+  T* val_;
+};
+
+
+/**
+ * Default traits for Persistent. This class does not allow
+ * use of the copy constructor or assignment operator.
+ * At present kResetInDestructor is not set, but that will change in a future
+ * version.
+ */
+template<class T>
+class NonCopyablePersistentTraits {
+ public:
+  typedef Persistent<T, NonCopyablePersistentTraits<T> > NonCopyablePersistent;
+  static const bool kResetInDestructor = false;
+  template<class S, class M>
+  V8_INLINE static void Copy(const Persistent<S, M>& source,
+                             NonCopyablePersistent* dest) {
+    Uncompilable<Object>();
+  }
+  // TODO(dcarney): come up with a good compile error here.
+  template<class O> V8_INLINE static void Uncompilable() {
+    TYPE_CHECK(O, Primitive);
+  }
+};
+
+
+/**
+ * Helper class traits to allow copying and assignment of Persistent.
+ * This will clone the contents of storage cell, but not any of the flags, etc.
+ */
+template<class T>
+struct CopyablePersistentTraits {
+  typedef Persistent<T, CopyablePersistentTraits<T> > CopyablePersistent;
+  static const bool kResetInDestructor = true;
+  template<class S, class M>
+  static V8_INLINE void Copy(const Persistent<S, M>& source,
+                             CopyablePersistent* dest) {
+    // do nothing, just allow copy
+  }
+};
+
+
+/**
+ * A PersistentBase which allows copy and assignment.
+ *
+ * Copy, assignment and destructor behavior is controlled by the traits
+ * class M.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T, class M> class Persistent : public PersistentBase<T> {
+ public:
+  /**
+   * A Persistent with no storage cell.
+   */
+  V8_INLINE Persistent() : PersistentBase<T>(0) { }
+  /**
+   * Construct a Persistent from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Persistent(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Persistent from a Persistent.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S, class M2>
+  V8_INLINE Persistent(Isolate* isolate, const Persistent<S, M2>& that)
+    : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * The copy constructors and assignment operator create a Persistent
+   * exactly as the Persistent constructor, but the Copy function from the
+   * traits class is called, allowing the setting of flags based on the
+   * copied Persistent.
+   */
+  V8_INLINE Persistent(const Persistent& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent(const Persistent<S, M2>& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  V8_INLINE Persistent& operator=(const Persistent& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent& operator=(const Persistent<S, M2>& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  /**
+   * The destructor will dispose the Persistent based on the
+   * kResetInDestructor flags in the traits class.  Since not calling dispose
+   * can result in a memory leak, it is recommended to always set this flag.
+   */
+  V8_INLINE ~Persistent() {
+    if (M::kResetInDestructor) this->Reset();
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE static Persistent<T>& Cast(const Persistent<S>& that) {  // NOLINT
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (!that.IsEmpty()) T::Cast(*that);
+#endif
+    return reinterpret_cast<Persistent<T>&>(const_cast<Persistent<S>&>(that));
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE Persistent<S>& As() const {  // NOLINT
+    return Persistent<S>::Cast(*this);
+  }
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template<class F> friend class ReturnValue;
+
+  explicit V8_INLINE Persistent(T* that) : PersistentBase<T>(that) {}
+  V8_INLINE T* operator*() const { return this->val_; }
+  template<class S, class M2>
+  V8_INLINE void Copy(const Persistent<S, M2>& that);
+};
+
+
+/**
+ * A PersistentBase which has move semantics.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T>
+class Global : public PersistentBase<T> {
+ public:
+  /**
+   * A Global with no storage cell.
+   */
+  V8_INLINE Global() : PersistentBase<T>(nullptr) {}
+  /**
+   * Construct a Global from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Global from a PersistentBase.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, const PersistentBase<S>& that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, that.val_)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Move constructor.
+   */
+  V8_INLINE Global(Global&& other) : PersistentBase<T>(other.val_) {  // NOLINT
+    other.val_ = nullptr;
+  }
+  V8_INLINE ~Global() { this->Reset(); }
+  /**
+   * Move via assignment.
+   */
+  template <class S>
+  V8_INLINE Global& operator=(Global<S>&& rhs) {  // NOLINT
+    TYPE_CHECK(T, S);
+    if (this != &rhs) {
+      this->Reset();
+      this->val_ = rhs.val_;
+      rhs.val_ = nullptr;
+    }
+    return *this;
+  }
+  /**
+   * Pass allows returning uniques from functions, etc.
+   */
+  Global Pass() { return static_cast<Global&&>(*this); }  // NOLINT
+
+  /*
+   * For compatibility with Chromium's base::Bind (base::Passed).
+   */
+  typedef void MoveOnlyTypeForCPP03;
+
+  Global(const Global&) = delete;
+  void operator=(const Global&) = delete;
+
+ private:
+  template <class F>
+  friend class ReturnValue;
+  V8_INLINE T* operator*() const { return this->val_; }
+};
+
+
+// UniquePersistent is an alias for Global for historical reason.
+template <class T>
+using UniquePersistent = Global<T>;
+
+
+ /**
+ * A stack-allocated class that governs a number of local handles.
+ * After a handle scope has been created, all local handles will be
+ * allocated within that handle scope until either the handle scope is
+ * deleted or another handle scope is created.  If there is already a
+ * handle scope and a new one is created, all allocations will take
+ * place in the new handle scope until it is deleted.  After that,
+ * new handles will again be allocated in the original handle scope.
+ *
+ * After the handle scope of a local handle has been deleted the
+ * garbage collector will no longer track the object stored in the
+ * handle and may deallocate it.  The behavior of accessing a handle
+ * for which the handle scope has been deleted is undefined.
+ */
+class V8_EXPORT HandleScope {
+ public:
+  explicit HandleScope(Isolate* isolate);
+
+  ~HandleScope();
+
+  /**
+   * Counts the number of allocated handles.
+   */
+  static int NumberOfHandles(Isolate* isolate);
+
+  V8_INLINE Isolate* GetIsolate() const {
+    return reinterpret_cast<Isolate*>(isolate_);
+  }
+
+  HandleScope(const HandleScope&) = delete;
+  void operator=(const HandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ protected:
+  V8_INLINE HandleScope() {}
+
+  void Initialize(Isolate* isolate);
+
+  static internal::Object** CreateHandle(internal::Isolate* isolate,
+                                         internal::Object* value);
+
+ private:
+  // Uses heap_object to obtain the current Isolate.
+  static internal::Object** CreateHandle(internal::HeapObject* heap_object,
+                                         internal::Object* value);
+
+  internal::Isolate* isolate_;
+  internal::Object** prev_next_;
+  internal::Object** prev_limit_;
+
+  // Local::New uses CreateHandle with an Isolate* parameter.
+  template<class F> friend class Local;
+
+  // Object::GetInternalField and Context::GetEmbedderData use CreateHandle with
+  // a HeapObject* in their shortcuts.
+  friend class Object;
+  friend class Context;
+};
+
+
+/**
+ * A HandleScope which first allocates a handle in the current scope
+ * which will be later filled with the escape value.
+ */
+class V8_EXPORT EscapableHandleScope : public HandleScope {
+ public:
+  explicit EscapableHandleScope(Isolate* isolate);
+  V8_INLINE ~EscapableHandleScope() {}
+
+  /**
+   * Pushes the value into the previous scope and returns a handle to it.
+   * Cannot be called twice.
+   */
+  template <class T>
+  V8_INLINE Local<T> Escape(Local<T> value) {
+    internal::Object** slot =
+        Escape(reinterpret_cast<internal::Object**>(*value));
+    return Local<T>(reinterpret_cast<T*>(slot));
+  }
+
+  EscapableHandleScope(const EscapableHandleScope&) = delete;
+  void operator=(const EscapableHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Object** Escape(internal::Object** escape_value);
+  internal::Object** escape_slot_;
+};
+
+/**
+ * A SealHandleScope acts like a handle scope in which no handle allocations
+ * are allowed. It can be useful for debugging handle leaks.
+ * Handles can be allocated within inner normal HandleScopes.
+ */
+class V8_EXPORT SealHandleScope {
+ public:
+  SealHandleScope(Isolate* isolate);
+  ~SealHandleScope();
+
+  SealHandleScope(const SealHandleScope&) = delete;
+  void operator=(const SealHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Isolate* const isolate_;
+  internal::Object** prev_limit_;
+  int prev_sealed_level_;
+};
+
+
+// --- Special objects ---
+
+
+/**
+ * The superclass of values and API object templates.
+ */
+class V8_EXPORT Data {
+ private:
+  Data();
+};
+
+
+/**
+ * The optional attributes of ScriptOrigin.
+ */
+class ScriptOriginOptions {
+ public:
+  V8_INLINE ScriptOriginOptions(bool is_shared_cross_origin = false,
+                                bool is_opaque = false, bool is_wasm = false,
+                                bool is_module = false)
+      : flags_((is_shared_cross_origin ? kIsSharedCrossOrigin : 0) |
+               (is_wasm ? kIsWasm : 0) | (is_opaque ? kIsOpaque : 0) |
+               (is_module ? kIsModule : 0)) {}
+  V8_INLINE ScriptOriginOptions(int flags)
+      : flags_(flags &
+               (kIsSharedCrossOrigin | kIsOpaque | kIsWasm | kIsModule)) {}
+
+  bool IsSharedCrossOrigin() const {
+    return (flags_ & kIsSharedCrossOrigin) != 0;
+  }
+  bool IsOpaque() const { return (flags_ & kIsOpaque) != 0; }
+  bool IsWasm() const { return (flags_ & kIsWasm) != 0; }
+  bool IsModule() const { return (flags_ & kIsModule) != 0; }
+
+  int Flags() const { return flags_; }
+
+ private:
+  enum {
+    kIsSharedCrossOrigin = 1,
+    kIsOpaque = 1 << 1,
+    kIsWasm = 1 << 2,
+    kIsModule = 1 << 3
+  };
+  const int flags_;
+};
+
+/**
+ * The origin, within a file, of a script.
+ */
+class ScriptOrigin {
+ public:
+  V8_INLINE ScriptOrigin(
+      Local<Value> resource_name,
+      Local<Integer> resource_line_offset = Local<Integer>(),
+      Local<Integer> resource_column_offset = Local<Integer>(),
+      Local<Boolean> resource_is_shared_cross_origin = Local<Boolean>(),
+      Local<Integer> script_id = Local<Integer>(),
+      Local<Value> source_map_url = Local<Value>(),
+      Local<Boolean> resource_is_opaque = Local<Boolean>(),
+      Local<Boolean> is_wasm = Local<Boolean>(),
+      Local<Boolean> is_module = Local<Boolean>());
+
+  V8_INLINE Local<Value> ResourceName() const;
+  V8_INLINE Local<Integer> ResourceLineOffset() const;
+  V8_INLINE Local<Integer> ResourceColumnOffset() const;
+  /**
+    * Returns true for embedder's debugger scripts
+    */
+  V8_INLINE Local<Integer> ScriptID() const;
+  V8_INLINE Local<Value> SourceMapUrl() const;
+  V8_INLINE ScriptOriginOptions Options() const { return options_; }
+
+ private:
+  Local<Value> resource_name_;
+  Local<Integer> resource_line_offset_;
+  Local<Integer> resource_column_offset_;
+  ScriptOriginOptions options_;
+  Local<Integer> script_id_;
+  Local<Value> source_map_url_;
+};
+
+
+/**
+ * A compiled JavaScript script, not yet tied to a Context.
+ */
+class V8_EXPORT UnboundScript {
+ public:
+  /**
+   * Binds the script to the currently entered context.
+   */
+  Local<Script> BindToCurrentContext();
+
+  int GetId();
+  Local<Value> GetScriptName();
+
+  /**
+   * Data read from magic sourceURL comments.
+   */
+  Local<Value> GetSourceURL();
+  /**
+   * Data read from magic sourceMappingURL comments.
+   */
+  Local<Value> GetSourceMappingURL();
+
+  /**
+   * Returns zero based line number of the code_pos location in the script.
+   * -1 will be returned if no information available.
+   */
+  int GetLineNumber(int code_pos);
+
+  static const int kNoScriptId = 0;
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT Module {
+ public:
+  /**
+   * Returns the number of modules requested by this module.
+   */
+  int GetModuleRequestsLength() const;
+
+  /**
+   * Returns the ith module specifier in this module.
+   * i must be < GetModuleRequestsLength() and >= 0.
+   */
+  Local<String> GetModuleRequest(int i) const;
+
+  /**
+   * Returns the identity hash for this object.
+   */
+  int GetIdentityHash() const;
+
+  typedef MaybeLocal<Module> (*ResolveCallback)(Local<Context> context,
+                                                Local<String> specifier,
+                                                Local<Module> referrer);
+
+  /**
+   * ModuleDeclarationInstantiation
+   *
+   * Returns false if an exception occurred during instantiation. (In the case
+   * where the callback throws an exception, that exception is propagated.)
+   */
+  V8_WARN_UNUSED_RESULT bool Instantiate(Local<Context> context,
+                                         ResolveCallback callback);
+
+  /**
+   * ModuleEvaluation
+   *
+   * Returns the completion value.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Evaluate(Local<Context> context);
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT DynamicImportResult {
+ public:
+  /**
+   * Resolves the promise with the namespace object of the given
+   * module.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportSuccess(Local<Context> context,
+                                                        Local<Module> module);
+
+  /**
+   * Rejects the promise with the given exception.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportFailure(Local<Context> context,
+                                                        Local<Value> exception);
+};
+
+/**
+ * A compiled JavaScript script, tied to a Context which was active when the
+ * script was compiled.
+ */
+class V8_EXPORT Script {
+ public:
+  /**
+   * A shorthand for ScriptCompiler::Compile().
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Script> Compile(Local<String> source,
+                            ScriptOrigin* origin = nullptr));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Local<String> source,
+      ScriptOrigin* origin = nullptr);
+
+  static Local<Script> V8_DEPRECATE_SOON("Use maybe version",
+                                         Compile(Local<String> source,
+                                                 Local<String> file_name));
+
+  /**
+   * Runs the script returning the resulting value. It will be run in the
+   * context in which it was created (ScriptCompiler::CompileBound or
+   * UnboundScript::BindToCurrentContext()).
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Run());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Run(Local<Context> context);
+
+  /**
+   * Returns the corresponding context-unbound script.
+   */
+  Local<UnboundScript> GetUnboundScript();
+};
+
+
+/**
+ * For compiling scripts.
+ */
+class V8_EXPORT ScriptCompiler {
+ public:
+  /**
+   * Compilation data that the embedder can cache and pass back to speed up
+   * future compilations. The data is produced if the CompilerOptions passed to
+   * the compilation functions in ScriptCompiler contains produce_data_to_cache
+   * = true. The data to cache can then can be retrieved from
+   * UnboundScript.
+   */
+  struct V8_EXPORT CachedData {
+    enum BufferPolicy {
+      BufferNotOwned,
+      BufferOwned
+    };
+
+    CachedData()
+        : data(NULL),
+          length(0),
+          rejected(false),
+          buffer_policy(BufferNotOwned) {}
+
+    // If buffer_policy is BufferNotOwned, the caller keeps the ownership of
+    // data and guarantees that it stays alive until the CachedData object is
+    // destroyed. If the policy is BufferOwned, the given data will be deleted
+    // (with delete[]) when the CachedData object is destroyed.
+    CachedData(const uint8_t* data, int length,
+               BufferPolicy buffer_policy = BufferNotOwned);
+    ~CachedData();
+    // TODO(marja): Async compilation; add constructors which take a callback
+    // which will be called when V8 no longer needs the data.
+    const uint8_t* data;
+    int length;
+    bool rejected;
+    BufferPolicy buffer_policy;
+
+    // Prevent copying.
+    CachedData(const CachedData&) = delete;
+    CachedData& operator=(const CachedData&) = delete;
+  };
+
+  /**
+   * Source code which can be then compiled to a UnboundScript or Script.
+   */
+  class Source {
+   public:
+    // Source takes ownership of CachedData.
+    V8_INLINE Source(Local<String> source_string, const ScriptOrigin& origin,
+           CachedData* cached_data = NULL);
+    V8_INLINE Source(Local<String> source_string,
+                     CachedData* cached_data = NULL);
+    V8_INLINE ~Source();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the Source object is
+    // alive.
+    V8_INLINE const CachedData* GetCachedData() const;
+
+    V8_INLINE const ScriptOriginOptions& GetResourceOptions() const;
+
+    // Prevent copying.
+    Source(const Source&) = delete;
+    Source& operator=(const Source&) = delete;
+
+   private:
+    friend class ScriptCompiler;
+
+    Local<String> source_string;
+
+    // Origin information
+    Local<Value> resource_name;
+    Local<Integer> resource_line_offset;
+    Local<Integer> resource_column_offset;
+    ScriptOriginOptions resource_options;
+    Local<Value> source_map_url;
+
+    // Cached data from previous compilation (if a kConsume*Cache flag is
+    // set), or hold newly generated cache data (kProduce*Cache flags) are
+    // set when calling a compile method.
+    CachedData* cached_data;
+  };
+
+  /**
+   * For streaming incomplete script data to V8. The embedder should implement a
+   * subclass of this class.
+   */
+  class V8_EXPORT ExternalSourceStream {
+   public:
+    virtual ~ExternalSourceStream() {}
+
+    /**
+     * V8 calls this to request the next chunk of data from the embedder. This
+     * function will be called on a background thread, so it's OK to block and
+     * wait for the data, if the embedder doesn't have data yet. Returns the
+     * length of the data returned. When the data ends, GetMoreData should
+     * return 0. Caller takes ownership of the data.
+     *
+     * When streaming UTF-8 data, V8 handles multi-byte characters split between
+     * two data chunks, but doesn't handle multi-byte characters split between
+     * more than two data chunks. The embedder can avoid this problem by always
+     * returning at least 2 bytes of data.
+     *
+     * If the embedder wants to cancel the streaming, they should make the next
+     * GetMoreData call return 0. V8 will interpret it as end of data (and most
+     * probably, parsing will fail). The streaming task will return as soon as
+     * V8 has parsed the data it received so far.
+     */
+    virtual size_t GetMoreData(const uint8_t** src) = 0;
+
+    /**
+     * V8 calls this method to set a 'bookmark' at the current position in
+     * the source stream, for the purpose of (maybe) later calling
+     * ResetToBookmark. If ResetToBookmark is called later, then subsequent
+     * calls to GetMoreData should return the same data as they did when
+     * SetBookmark was called earlier.
+     *
+     * The embedder may return 'false' to indicate it cannot provide this
+     * functionality.
+     */
+    virtual bool SetBookmark();
+
+    /**
+     * V8 calls this to return to a previously set bookmark.
+     */
+    virtual void ResetToBookmark();
+  };
+
+
+  /**
+   * Source code which can be streamed into V8 in pieces. It will be parsed
+   * while streaming. It can be compiled after the streaming is complete.
+   * StreamedSource must be kept alive while the streaming task is ran (see
+   * ScriptStreamingTask below).
+   */
+  class V8_EXPORT StreamedSource {
+   public:
+    enum Encoding { ONE_BYTE, TWO_BYTE, UTF8 };
+
+    StreamedSource(ExternalSourceStream* source_stream, Encoding encoding);
+    ~StreamedSource();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the StreamedSource
+    // object is alive.
+    const CachedData* GetCachedData() const;
+
+    internal::StreamedSource* impl() const { return impl_; }
+
+    // Prevent copying.
+    StreamedSource(const StreamedSource&) = delete;
+    StreamedSource& operator=(const StreamedSource&) = delete;
+
+   private:
+    internal::StreamedSource* impl_;
+  };
+
+  /**
+   * A streaming task which the embedder must run on a background thread to
+   * stream scripts into V8. Returned by ScriptCompiler::StartStreamingScript.
+   */
+  class ScriptStreamingTask {
+   public:
+    virtual ~ScriptStreamingTask() {}
+    virtual void Run() = 0;
+  };
+
+  enum CompileOptions {
+    kNoCompileOptions = 0,
+    kProduceParserCache,
+    kConsumeParserCache,
+    kProduceCodeCache,
+    kConsumeCodeCache
+  };
+
+  /**
+   * Compiles the specified script (context-independent).
+   * Cached data as part of the source object can be optionally produced to be
+   * consumed later to speed up compilation of identical source scripts.
+   *
+   * Note that when producing cached data, the source must point to NULL for
+   * cached data. When consuming cached data, the cached data must have been
+   * produced by the same version of V8.
+   *
+   * \param source Script source code.
+   * \return Compiled script object (context independent; for running it must be
+   *   bound to a context).
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<UnboundScript> CompileUnbound(
+                           Isolate* isolate, Source* source,
+                           CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundScript(
+      Isolate* isolate, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles the specified script (bound to current context).
+   *
+   * \param source Script source code.
+   * \param pre_data Pre-parsing data, as obtained by ScriptData::PreCompile()
+   *   using pre_data speeds compilation if it's done multiple times.
+   *   Owned by caller, no references are kept when this function returns.
+   * \return Compiled script object, bound to the context that was active
+   *   when this function was called. When run it will always use this
+   *   context.
+   */
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<Script> Compile(Isolate* isolate, Source* source,
+                            CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Returns a task which streams script data into V8, or NULL if the script
+   * cannot be streamed. The user is responsible for running the task on a
+   * background thread and deleting it. When ran, the task starts parsing the
+   * script, and it will request data from the StreamedSource as needed. When
+   * ScriptStreamingTask::Run exits, all data has been streamed and the script
+   * can be compiled (see Compile below).
+   *
+   * This API allows to start the streaming with as little data as possible, and
+   * the remaining data (for example, the ScriptOrigin) is passed to Compile.
+   */
+  static ScriptStreamingTask* StartStreamingScript(
+      Isolate* isolate, StreamedSource* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles a streamed script (bound to current context).
+   *
+   * This can only be called after the streaming has finished
+   * (ScriptStreamingTask has been run). V8 doesn't construct the source string
+   * during streaming, so the embedder needs to pass the full source here.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<Script> Compile(Isolate* isolate,
+                                             StreamedSource* source,
+                                             Local<String> full_source_string,
+                                             const ScriptOrigin& origin));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, StreamedSource* source,
+      Local<String> full_source_string, const ScriptOrigin& origin);
+
+  /**
+   * Return a version tag for CachedData for the current V8 version & flags.
+   *
+   * This value is meant only for determining whether a previously generated
+   * CachedData instance is still valid; the tag has no other meaing.
+   *
+   * Background: The data carried by CachedData may depend on the exact
+   *   V8 version number or current compiler flags. This means that when
+   *   persisting CachedData, the embedder must take care to not pass in
+   *   data from another V8 version, or the same version with different
+   *   features enabled.
+   *
+   *   The easiest way to do so is to clear the embedder's cache on any
+   *   such change.
+   *
+   *   Alternatively, this tag can be stored alongside the cached data and
+   *   compared when it is being used.
+   */
+  static uint32_t CachedDataVersionTag();
+
+  /**
+   * This is an unfinished experimental feature, and is only exposed
+   * here for internal testing purposes. DO NOT USE.
+   *
+   * Compile an ES module, returning a Module that encapsulates
+   * the compiled code.
+   *
+   * Corresponds to the ParseModule abstract operation in the
+   * ECMAScript specification.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Module> CompileModule(
+      Isolate* isolate, Source* source);
+
+  /**
+   * Compile a function for a given context. This is equivalent to running
+   *
+   * with (obj) {
+   *   return function(args) { ... }
+   * }
+   *
+   * It is possible to specify multiple context extensions (obj in the above
+   * example).
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Function> CompileFunctionInContext(
+                               Isolate* isolate, Source* source,
+                               Local<Context> context, size_t arguments_count,
+                               Local<String> arguments[],
+                               size_t context_extension_count,
+                               Local<Object> context_extensions[]));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Function> CompileFunctionInContext(
+      Local<Context> context, Source* source, size_t arguments_count,
+      Local<String> arguments[], size_t context_extension_count,
+      Local<Object> context_extensions[]);
+
+ private:
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundInternal(
+      Isolate* isolate, Source* source, CompileOptions options);
+};
+
+
+/**
+ * An error message.
+ */
+class V8_EXPORT Message {
+ public:
+  Local<String> Get() const;
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<String> GetSourceLine() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> GetSourceLine(
+      Local<Context> context) const;
+
+  /**
+   * Returns the origin for the script from where the function causing the
+   * error originates.
+   */
+  ScriptOrigin GetScriptOrigin() const;
+
+  /**
+   * Returns the resource name for the script from where the function causing
+   * the error originates.
+   */
+  Local<Value> GetScriptResourceName() const;
+
+  /**
+   * Exception stack trace. By default stack traces are not captured for
+   * uncaught exceptions. SetCaptureStackTraceForUncaughtExceptions allows
+   * to change this option.
+   */
+  Local<StackTrace> GetStackTrace() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetLineNumber() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetLineNumber(Local<Context> context) const;
+
+  /**
+   * Returns the index within the script of the first character where
+   * the error occurred.
+   */
+  int GetStartPosition() const;
+
+  /**
+   * Returns the index within the script of the last character where
+   * the error occurred.
+   */
+  int GetEndPosition() const;
+
+  /**
+   * Returns the error level of the message.
+   */
+  int ErrorLevel() const;
+
+  /**
+   * Returns the index within the line of the first character where
+   * the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetStartColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetStartColumn(Local<Context> context) const;
+
+  /**
+   * Returns the index within the line of the last character where
+   * the error occurred.
+   */
+  V8_DEPRECATED("Use maybe version", int GetEndColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetEndColumn(Local<Context> context) const;
+
+  /**
+   * Passes on the value set by the embedder when it fed the script from which
+   * this Message was generated to V8.
+   */
+  bool IsSharedCrossOrigin() const;
+  bool IsOpaque() const;
+
+  // TODO(1245381): Print to a string instead of on a FILE.
+  static void PrintCurrentStackTrace(Isolate* isolate, FILE* out);
+
+  static const int kNoLineNumberInfo = 0;
+  static const int kNoColumnInfo = 0;
+  static const int kNoScriptIdInfo = 0;
+};
+
+
+/**
+ * Representation of a JavaScript stack trace. The information collected is a
+ * snapshot of the execution stack and the information remains valid after
+ * execution continues.
+ */
+class V8_EXPORT StackTrace {
+ public:
+  /**
+   * Flags that determine what information is placed captured for each
+   * StackFrame when grabbing the current stack trace.
+   * Note: these options are deprecated and we always collect all available
+   * information (kDetailed).
+   */
+  enum StackTraceOptions {
+    kLineNumber = 1,
+    kColumnOffset = 1 << 1 | kLineNumber,
+    kScriptName = 1 << 2,
+    kFunctionName = 1 << 3,
+    kIsEval = 1 << 4,
+    kIsConstructor = 1 << 5,
+    kScriptNameOrSourceURL = 1 << 6,
+    kScriptId = 1 << 7,
+    kExposeFramesAcrossSecurityOrigins = 1 << 8,
+    kOverview = kLineNumber | kColumnOffset | kScriptName | kFunctionName,
+    kDetailed = kOverview | kIsEval | kIsConstructor | kScriptNameOrSourceURL
+  };
+
+  /**
+   * Returns a StackFrame at a particular index.
+   */
+  Local<StackFrame> GetFrame(uint32_t index) const;
+
+  /**
+   * Returns the number of StackFrames.
+   */
+  int GetFrameCount() const;
+
+  /**
+   * Returns StackTrace as a v8::Array that contains StackFrame objects.
+   */
+  V8_DEPRECATED("Use native API instead", Local<Array> AsArray());
+
+  /**
+   * Grab a snapshot of the current JavaScript execution stack.
+   *
+   * \param frame_limit The maximum number of stack frames we want to capture.
+   * \param options Enumerates the set of things we will capture for each
+   *   StackFrame.
+   */
+  static Local<StackTrace> CurrentStackTrace(
+      Isolate* isolate, int frame_limit, StackTraceOptions options = kDetailed);
+};
+
+
+/**
+ * A single JavaScript stack frame.
+ */
+class V8_EXPORT StackFrame {
+ public:
+  /**
+   * Returns the number, 1-based, of the line for the associate function call.
+   * This method will return Message::kNoLineNumberInfo if it is unable to
+   * retrieve the line number, or if kLineNumber was not passed as an option
+   * when capturing the StackTrace.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns the 1-based column offset on the line for the associated function
+   * call.
+   * This method will return Message::kNoColumnInfo if it is unable to retrieve
+   * the column number, or if kColumnOffset was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetColumn() const;
+
+  /**
+   * Returns the id of the script for the function for this StackFrame.
+   * This method will return Message::kNoScriptIdInfo if it is unable to
+   * retrieve the script id, or if kScriptId was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetScriptId() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame.
+   */
+  Local<String> GetScriptName() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame or sourceURL value if the script name
+   * is undefined and its source ends with //# sourceURL=... string or
+   * deprecated //@ sourceURL=... string.
+   */
+  Local<String> GetScriptNameOrSourceURL() const;
+
+  /**
+   * Returns the name of the function associated with this stack frame.
+   */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns whether or not the associated function is compiled via a call to
+   * eval().
+   */
+  bool IsEval() const;
+
+  /**
+   * Returns whether or not the associated function is called as a
+   * constructor via "new".
+   */
+  bool IsConstructor() const;
+
+  /**
+   * Returns whether or not the associated functions is defined in wasm.
+   */
+  bool IsWasm() const;
+};
+
+
+// A StateTag represents a possible state of the VM.
+enum StateTag { JS, GC, COMPILER, OTHER, EXTERNAL, IDLE };
+
+// A RegisterState represents the current state of registers used
+// by the sampling profiler API.
+struct RegisterState {
+  RegisterState() : pc(nullptr), sp(nullptr), fp(nullptr) {}
+  void* pc;  // Instruction pointer.
+  void* sp;  // Stack pointer.
+  void* fp;  // Frame pointer.
+};
+
+// The output structure filled up by GetStackSample API function.
+struct SampleInfo {
+  size_t frames_count;            // Number of frames collected.
+  StateTag vm_state;              // Current VM state.
+  void* external_callback_entry;  // External callback address if VM is
+                                  // executing an external callback.
+};
+
+/**
+ * A JSON Parser and Stringifier.
+ */
+class V8_EXPORT JSON {
+ public:
+  /**
+   * Tries to parse the string |json_string| and returns it as value if
+   * successful.
+   *
+   * \param json_string The string to parse.
+   * \return The corresponding value if successfully parsed.
+   */
+  static V8_DEPRECATED("Use the maybe version taking context",
+                       Local<Value> Parse(Local<String> json_string));
+  static V8_DEPRECATE_SOON("Use the maybe version taking context",
+                           MaybeLocal<Value> Parse(Isolate* isolate,
+                                                   Local<String> json_string));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> Parse(
+      Local<Context> context, Local<String> json_string);
+
+  /**
+   * Tries to stringify the JSON-serializable object |json_object| and returns
+   * it as string if successful.
+   *
+   * \param json_object The JSON-serializable object to stringify.
+   * \return The corresponding string if successfully stringified.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> Stringify(
+      Local<Context> context, Local<Object> json_object,
+      Local<String> gap = Local<String>());
+};
+
+/**
+ * Value serialization compatible with the HTML structured clone algorithm.
+ * The format is backward-compatible (i.e. safe to store to disk).
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueSerializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * Handles the case where a DataCloneError would be thrown in the structured
+     * clone spec. Other V8 embedders may throw some other appropriate exception
+     * type.
+     */
+    virtual void ThrowDataCloneError(Local<String> message) = 0;
+
+    /**
+     * The embedder overrides this method to write some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * Nothing<bool>() returned.
+     */
+    virtual Maybe<bool> WriteHostObject(Isolate* isolate, Local<Object> object);
+
+    /**
+     * Called when the ValueSerializer is going to serialize a
+     * SharedArrayBuffer object. The embedder must return an ID for the
+     * object, using the same ID if this SharedArrayBuffer has already been
+     * serialized in this buffer. When deserializing, this ID will be passed to
+     * ValueDeserializer::TransferSharedArrayBuffer as |transfer_id|.
+     *
+     * If the object cannot be serialized, an
+     * exception should be thrown and Nothing<uint32_t>() returned.
+     */
+    virtual Maybe<uint32_t> GetSharedArrayBufferId(
+        Isolate* isolate, Local<SharedArrayBuffer> shared_array_buffer);
+
+    virtual Maybe<uint32_t> GetWasmModuleTransferId(
+        Isolate* isolate, Local<WasmCompiledModule> module);
+    /**
+     * Allocates memory for the buffer of at least the size provided. The actual
+     * size (which may be greater or equal) is written to |actual_size|. If no
+     * buffer has been allocated yet, nullptr will be provided.
+     *
+     * If the memory cannot be allocated, nullptr should be returned.
+     * |actual_size| will be ignored. It is assumed that |old_buffer| is still
+     * valid in this case and has not been modified.
+     */
+    virtual void* ReallocateBufferMemory(void* old_buffer, size_t size,
+                                         size_t* actual_size);
+
+    /**
+     * Frees a buffer allocated with |ReallocateBufferMemory|.
+     */
+    virtual void FreeBufferMemory(void* buffer);
+  };
+
+  explicit ValueSerializer(Isolate* isolate);
+  ValueSerializer(Isolate* isolate, Delegate* delegate);
+  ~ValueSerializer();
+
+  /**
+   * Writes out a header, which includes the format version.
+   */
+  void WriteHeader();
+
+  /**
+   * Serializes a JavaScript value into the buffer.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> WriteValue(Local<Context> context,
+                                               Local<Value> value);
+
+  /**
+   * Returns the stored data. This serializer should not be used once the buffer
+   * is released. The contents are undefined if a previous write has failed.
+   */
+  V8_DEPRECATE_SOON("Use Release()", std::vector<uint8_t> ReleaseBuffer());
+
+  /**
+   * Returns the stored data (allocated using the delegate's
+   * AllocateBufferMemory) and its size. This serializer should not be used once
+   * the buffer is released. The contents are undefined if a previous write has
+   * failed.
+   */
+  V8_WARN_UNUSED_RESULT std::pair<uint8_t*, size_t> Release();
+
+  /**
+   * Marks an ArrayBuffer as havings its contents transferred out of band.
+   * Pass the corresponding ArrayBuffer in the deserializing context to
+   * ValueDeserializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   */
+  V8_DEPRECATE_SOON("Use Delegate::GetSharedArrayBufferId",
+                    void TransferSharedArrayBuffer(
+                        uint32_t transfer_id,
+                        Local<SharedArrayBuffer> shared_array_buffer));
+
+  /**
+   * Indicate whether to treat ArrayBufferView objects as host objects,
+   * i.e. pass them to Delegate::WriteHostObject. This should not be
+   * called when no Delegate was passed.
+   *
+   * The default is not to treat ArrayBufferViews as host objects.
+   */
+  void SetTreatArrayBufferViewsAsHostObjects(bool mode);
+
+  /**
+   * Write raw data in various common formats to the buffer.
+   * Note that integer types are written in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::WriteHostObject.
+   */
+  void WriteUint32(uint32_t value);
+  void WriteUint64(uint64_t value);
+  void WriteDouble(double value);
+  void WriteRawBytes(const void* source, size_t length);
+
+ private:
+  ValueSerializer(const ValueSerializer&) = delete;
+  void operator=(const ValueSerializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * Deserializes values from data written with ValueSerializer, or a compatible
+ * implementation.
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueDeserializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * The embedder overrides this method to read some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * MaybeLocal<Object>() returned.
+     */
+    virtual MaybeLocal<Object> ReadHostObject(Isolate* isolate);
+
+    /**
+     * Get a WasmCompiledModule given a transfer_id previously provided
+     * by ValueSerializer::GetWasmModuleTransferId
+     */
+    virtual MaybeLocal<WasmCompiledModule> GetWasmModuleFromId(
+        Isolate* isolate, uint32_t transfer_id);
+  };
+
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size);
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size,
+                    Delegate* delegate);
+  ~ValueDeserializer();
+
+  /**
+   * Reads and validates a header (including the format version).
+   * May, for example, reject an invalid or unsupported wire format.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> ReadHeader(Local<Context> context);
+
+  /**
+   * Deserializes a JavaScript value from the buffer.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> ReadValue(Local<Context> context);
+
+  /**
+   * Accepts the array buffer corresponding to the one passed previously to
+   * ValueSerializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   * The id is not necessarily in the same namespace as unshared ArrayBuffer
+   * objects.
+   */
+  void TransferSharedArrayBuffer(uint32_t id,
+                                 Local<SharedArrayBuffer> shared_array_buffer);
+
+  /**
+   * Must be called before ReadHeader to enable support for reading the legacy
+   * wire format (i.e., which predates this being shipped).
+   *
+   * Don't use this unless you need to read data written by previous versions of
+   * blink::ScriptValueSerializer.
+   */
+  void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);
+
+  /**
+   * Expect inline wasm in the data stream (rather than in-memory transfer)
+   */
+  void SetExpectInlineWasm(bool allow_inline_wasm);
+
+  /**
+   * Reads the underlying wire format version. Likely mostly to be useful to
+   * legacy code reading old wire format versions. Must be called after
+   * ReadHeader.
+   */
+  uint32_t GetWireFormatVersion() const;
+
+  /**
+   * Reads raw data in various common formats to the buffer.
+   * Note that integer types are read in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::ReadHostObject.
+   */
+  V8_WARN_UNUSED_RESULT bool ReadUint32(uint32_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadUint64(uint64_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadDouble(double* value);
+  V8_WARN_UNUSED_RESULT bool ReadRawBytes(size_t length, const void** data);
+
+ private:
+  ValueDeserializer(const ValueDeserializer&) = delete;
+  void operator=(const ValueDeserializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * A map whose keys are referenced weakly. It is similar to JavaScript WeakMap
+ * but can be created without entering a v8::Context and hence shouldn't
+ * escape to JavaScript.
+ */
+class V8_EXPORT NativeWeakMap : public Data {
+ public:
+  static Local<NativeWeakMap> New(Isolate* isolate);
+  void Set(Local<Value> key, Local<Value> value);
+  Local<Value> Get(Local<Value> key) const;
+  bool Has(Local<Value> key);
+  bool Delete(Local<Value> key);
+};
+
+
+// --- Value ---
+
+
+/**
+ * The superclass of all JavaScript values and objects.
+ */
+class V8_EXPORT Value : public Data {
+ public:
+  /**
+   * Returns true if this value is the undefined value.  See ECMA-262
+   * 4.3.10.
+   */
+  V8_INLINE bool IsUndefined() const;
+
+  /**
+   * Returns true if this value is the null value.  See ECMA-262
+   * 4.3.11.
+   */
+  V8_INLINE bool IsNull() const;
+
+  /**
+   * Returns true if this value is either the null or the undefined value.
+   * See ECMA-262
+   * 4.3.11. and 4.3.12
+   */
+  V8_INLINE bool IsNullOrUndefined() const;
+
+  /**
+  * Returns true if this value is true.
+  */
+  bool IsTrue() const;
+
+  /**
+   * Returns true if this value is false.
+   */
+  bool IsFalse() const;
+
+  /**
+   * Returns true if this value is a symbol or a string.
+   */
+  bool IsName() const;
+
+  /**
+   * Returns true if this value is an instance of the String type.
+   * See ECMA-262 8.4.
+   */
+  V8_INLINE bool IsString() const;
+
+  /**
+   * Returns true if this value is a symbol.
+   */
+  bool IsSymbol() const;
+
+  /**
+   * Returns true if this value is a function.
+   */
+  bool IsFunction() const;
+
+  /**
+   * Returns true if this value is an array. Note that it will return false for
+   * an Proxy for an array.
+   */
+  bool IsArray() const;
+
+  /**
+   * Returns true if this value is an object.
+   */
+  bool IsObject() const;
+
+  /**
+   * Returns true if this value is boolean.
+   */
+  bool IsBoolean() const;
+
+  /**
+   * Returns true if this value is a number.
+   */
+  bool IsNumber() const;
+
+  /**
+   * Returns true if this value is external.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this value is a 32-bit signed integer.
+   */
+  bool IsInt32() const;
+
+  /**
+   * Returns true if this value is a 32-bit unsigned integer.
+   */
+  bool IsUint32() const;
+
+  /**
+   * Returns true if this value is a Date.
+   */
+  bool IsDate() const;
+
+  /**
+   * Returns true if this value is an Arguments object.
+   */
+  bool IsArgumentsObject() const;
+
+  /**
+   * Returns true if this value is a Boolean object.
+   */
+  bool IsBooleanObject() const;
+
+  /**
+   * Returns true if this value is a Number object.
+   */
+  bool IsNumberObject() const;
+
+  /**
+   * Returns true if this value is a String object.
+   */
+  bool IsStringObject() const;
+
+  /**
+   * Returns true if this value is a Symbol object.
+   */
+  bool IsSymbolObject() const;
+
+  /**
+   * Returns true if this value is a NativeError.
+   */
+  bool IsNativeError() const;
+
+  /**
+   * Returns true if this value is a RegExp.
+   */
+  bool IsRegExp() const;
+
+  /**
+   * Returns true if this value is an async function.
+   */
+  bool IsAsyncFunction() const;
+
+  /**
+   * Returns true if this value is a Generator function.
+   */
+  bool IsGeneratorFunction() const;
+
+  /**
+   * Returns true if this value is a Generator object (iterator).
+   */
+  bool IsGeneratorObject() const;
+
+  /**
+   * Returns true if this value is a Promise.
+   */
+  bool IsPromise() const;
+
+  /**
+   * Returns true if this value is a Map.
+   */
+  bool IsMap() const;
+
+  /**
+   * Returns true if this value is a Set.
+   */
+  bool IsSet() const;
+
+  /**
+   * Returns true if this value is a Map Iterator.
+   */
+  bool IsMapIterator() const;
+
+  /**
+   * Returns true if this value is a Set Iterator.
+   */
+  bool IsSetIterator() const;
+
+  /**
+   * Returns true if this value is a WeakMap.
+   */
+  bool IsWeakMap() const;
+
+  /**
+   * Returns true if this value is a WeakSet.
+   */
+  bool IsWeakSet() const;
+
+  /**
+   * Returns true if this value is an ArrayBuffer.
+   */
+  bool IsArrayBuffer() const;
+
+  /**
+   * Returns true if this value is an ArrayBufferView.
+   */
+  bool IsArrayBufferView() const;
+
+  /**
+   * Returns true if this value is one of TypedArrays.
+   */
+  bool IsTypedArray() const;
+
+  /**
+   * Returns true if this value is an Uint8Array.
+   */
+  bool IsUint8Array() const;
+
+  /**
+   * Returns true if this value is an Uint8ClampedArray.
+   */
+  bool IsUint8ClampedArray() const;
+
+  /**
+   * Returns true if this value is an Int8Array.
+   */
+  bool IsInt8Array() const;
+
+  /**
+   * Returns true if this value is an Uint16Array.
+   */
+  bool IsUint16Array() const;
+
+  /**
+   * Returns true if this value is an Int16Array.
+   */
+  bool IsInt16Array() const;
+
+  /**
+   * Returns true if this value is an Uint32Array.
+   */
+  bool IsUint32Array() const;
+
+  /**
+   * Returns true if this value is an Int32Array.
+   */
+  bool IsInt32Array() const;
+
+  /**
+   * Returns true if this value is a Float32Array.
+   */
+  bool IsFloat32Array() const;
+
+  /**
+   * Returns true if this value is a Float64Array.
+   */
+  bool IsFloat64Array() const;
+
+  /**
+   * Returns true if this value is a DataView.
+   */
+  bool IsDataView() const;
+
+  /**
+   * Returns true if this value is a SharedArrayBuffer.
+   * This is an experimental feature.
+   */
+  bool IsSharedArrayBuffer() const;
+
+  /**
+   * Returns true if this value is a JavaScript Proxy.
+   */
+  bool IsProxy() const;
+
+  bool IsWebAssemblyCompiledModule() const;
+
+  V8_WARN_UNUSED_RESULT MaybeLocal<Boolean> ToBoolean(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToDetailString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> ToObject(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Integer> ToInteger(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToUint32(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Int32> ToInt32(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Boolean> ToBoolean(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Number> ToNumber(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<String> ToString(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<String> ToDetailString(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Object> ToObject(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Integer> ToInteger(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<Uint32> ToUint32(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Int32> ToInt32(Isolate* isolate) const);
+
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Boolean> ToBoolean() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Number> ToNumber() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<String> ToString() const);
+  inline V8_DEPRECATED("Use maybe version",
+                       Local<String> ToDetailString() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<Object> ToObject() const);
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Integer> ToInteger() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Uint32> ToUint32() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Int32> ToInt32() const);
+
+  /**
+   * Attempts to convert a string to an array index.
+   * Returns an empty handle if the conversion fails.
+   */
+  V8_DEPRECATED("Use maybe version", Local<Uint32> ToArrayIndex() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToArrayIndex(
+      Local<Context> context) const;
+
+  V8_WARN_UNUSED_RESULT Maybe<bool> BooleanValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<double> NumberValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int64_t> IntegerValue(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<uint32_t> Uint32Value(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int32_t> Int32Value(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version", bool BooleanValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", double NumberValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", int64_t IntegerValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", uint32_t Uint32Value() const);
+  V8_DEPRECATE_SOON("Use maybe version", int32_t Int32Value() const);
+
+  /** JS == */
+  V8_DEPRECATE_SOON("Use maybe version", bool Equals(Local<Value> that) const);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Equals(Local<Context> context,
+                                           Local<Value> that) const;
+  bool StrictEquals(Local<Value> that) const;
+  bool SameValue(Local<Value> that) const;
+
+  template <class T> V8_INLINE static Value* Cast(T* value);
+
+  Local<String> TypeOf(Isolate*);
+
+  Maybe<bool> InstanceOf(Local<Context> context, Local<Object> object);
+
+ private:
+  V8_INLINE bool QuickIsUndefined() const;
+  V8_INLINE bool QuickIsNull() const;
+  V8_INLINE bool QuickIsNullOrUndefined() const;
+  V8_INLINE bool QuickIsString() const;
+  bool FullIsUndefined() const;
+  bool FullIsNull() const;
+  bool FullIsString() const;
+};
+
+
+/**
+ * The superclass of primitive values.  See ECMA-262 4.3.2.
+ */
+class V8_EXPORT Primitive : public Value { };
+
+
+/**
+ * A primitive boolean value (ECMA-262, 4.3.14).  Either the true
+ * or false value.
+ */
+class V8_EXPORT Boolean : public Primitive {
+ public:
+  bool Value() const;
+  V8_INLINE static Boolean* Cast(v8::Value* obj);
+  V8_INLINE static Local<Boolean> New(Isolate* isolate, bool value);
+
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A superclass for symbols and strings.
+ */
+class V8_EXPORT Name : public Primitive {
+ public:
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses an inline property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  V8_INLINE static Name* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * A flag describing different modes of string creation.
+ *
+ * Aside from performance implications there are no differences between the two
+ * creation modes.
+ */
+enum class NewStringType {
+  /**
+   * Create a new string, always allocating new storage memory.
+   */
+  kNormal,
+
+  /**
+   * Acts as a hint that the string should be created in the
+   * old generation heap space and be deduplicated if an identical string
+   * already exists.
+   */
+  kInternalized
+};
+
+/**
+ * A JavaScript string value (ECMA-262, 4.3.17).
+ */
+class V8_EXPORT String : public Name {
+ public:
+  static const int kMaxLength = (1 << 28) - 16;
+
+  enum Encoding {
+    UNKNOWN_ENCODING = 0x1,
+    TWO_BYTE_ENCODING = 0x0,
+    ONE_BYTE_ENCODING = 0x8
+  };
+  /**
+   * Returns the number of characters (UTF-16 code units) in this string.
+   */
+  int Length() const;
+
+  /**
+   * Returns the number of bytes in the UTF-8 encoded
+   * representation of this string.
+   */
+  int Utf8Length() const;
+
+  /**
+   * Returns whether this string is known to contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Does not read the string.
+   * False negatives are possible.
+   */
+  bool IsOneByte() const;
+
+  /**
+   * Returns whether this string contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Will read the entire string in some cases.
+   */
+  bool ContainsOnlyOneByte() const;
+
+  /**
+   * Write the contents of the string to an external buffer.
+   * If no arguments are given, expects the buffer to be large
+   * enough to hold the entire string and NULL terminator. Copies
+   * the contents of the string and the NULL terminator into the
+   * buffer.
+   *
+   * WriteUtf8 will not write partial UTF-8 sequences, preferring to stop
+   * before the end of the buffer.
+   *
+   * Copies up to length characters into the output buffer.
+   * Only null-terminates if there is enough space in the buffer.
+   *
+   * \param buffer The buffer into which the string will be copied.
+   * \param start The starting position within the string at which
+   * copying begins.
+   * \param length The number of characters to copy from the string.  For
+   *    WriteUtf8 the number of bytes in the buffer.
+   * \param nchars_ref The number of characters written, can be NULL.
+   * \param options Various options that might affect performance of this or
+   *    subsequent operations.
+   * \return The number of characters copied to the buffer excluding the null
+   *    terminator.  For WriteUtf8: The number of bytes copied to the buffer
+   *    including the null terminator (if written).
+   */
+  enum WriteOptions {
+    NO_OPTIONS = 0,
+    HINT_MANY_WRITES_EXPECTED = 1,
+    NO_NULL_TERMINATION = 2,
+    PRESERVE_ONE_BYTE_NULL = 4,
+    // Used by WriteUtf8 to replace orphan surrogate code units with the
+    // unicode replacement character. Needs to be set to guarantee valid UTF-8
+    // output.
+    REPLACE_INVALID_UTF8 = 8
+  };
+
+  // 16-bit character codes.
+  int Write(uint16_t* buffer,
+            int start = 0,
+            int length = -1,
+            int options = NO_OPTIONS) const;
+  // One byte characters.
+  int WriteOneByte(uint8_t* buffer,
+                   int start = 0,
+                   int length = -1,
+                   int options = NO_OPTIONS) const;
+  // UTF-8 encoded characters.
+  int WriteUtf8(char* buffer,
+                int length = -1,
+                int* nchars_ref = NULL,
+                int options = NO_OPTIONS) const;
+
+  /**
+   * A zero length string.
+   */
+  V8_INLINE static Local<String> Empty(Isolate* isolate);
+
+  /**
+   * Returns true if the string is external
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if the string is both external and one-byte.
+   */
+  bool IsExternalOneByte() const;
+
+  class V8_EXPORT ExternalStringResourceBase {  // NOLINT
+   public:
+    virtual ~ExternalStringResourceBase() {}
+
+    virtual bool IsCompressible() const { return false; }
+
+   protected:
+    ExternalStringResourceBase() {}
+
+    /**
+     * Internally V8 will call this Dispose method when the external string
+     * resource is no longer needed. The default implementation will use the
+     * delete operator. This method can be overridden in subclasses to
+     * control how allocated external string resources are disposed.
+     */
+    virtual void Dispose() { delete this; }
+
+    // Disallow copying and assigning.
+    ExternalStringResourceBase(const ExternalStringResourceBase&) = delete;
+    void operator=(const ExternalStringResourceBase&) = delete;
+
+   private:
+    friend class internal::Heap;
+    friend class v8::String;
+  };
+
+  /**
+   * An ExternalStringResource is a wrapper around a two-byte string
+   * buffer that resides outside V8's heap. Implement an
+   * ExternalStringResource to manage the life cycle of the underlying
+   * buffer.  Note that the string data must be immutable.
+   */
+  class V8_EXPORT ExternalStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalStringResource() {}
+
+    /**
+     * The string data from the underlying buffer.
+     */
+    virtual const uint16_t* data() const = 0;
+
+    /**
+     * The length of the string. That is, the number of two-byte characters.
+     */
+    virtual size_t length() const = 0;
+
+   protected:
+    ExternalStringResource() {}
+  };
+
+  /**
+   * An ExternalOneByteStringResource is a wrapper around an one-byte
+   * string buffer that resides outside V8's heap. Implement an
+   * ExternalOneByteStringResource to manage the life cycle of the
+   * underlying buffer.  Note that the string data must be immutable
+   * and that the data must be Latin-1 and not UTF-8, which would require
+   * special treatment internally in the engine and do not allow efficient
+   * indexing.  Use String::New or convert to 16 bit data for non-Latin1.
+   */
+
+  class V8_EXPORT ExternalOneByteStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalOneByteStringResource() {}
+    /** The string data from the underlying buffer.*/
+    virtual const char* data() const = 0;
+    /** The number of Latin-1 characters in the string.*/
+    virtual size_t length() const = 0;
+   protected:
+    ExternalOneByteStringResource() {}
+  };
+
+  /**
+   * If the string is an external string, return the ExternalStringResourceBase
+   * regardless of the encoding, otherwise return NULL.  The encoding of the
+   * string is returned in encoding_out.
+   */
+  V8_INLINE ExternalStringResourceBase* GetExternalStringResourceBase(
+      Encoding* encoding_out) const;
+
+  /**
+   * Get the ExternalStringResource for an external string.  Returns
+   * NULL if IsExternal() doesn't return true.
+   */
+  V8_INLINE ExternalStringResource* GetExternalStringResource() const;
+
+  /**
+   * Get the ExternalOneByteStringResource for an external one-byte string.
+   * Returns NULL if IsExternalOneByte() doesn't return true.
+   */
+  const ExternalOneByteStringResource* GetExternalOneByteStringResource() const;
+
+  V8_INLINE static String* Cast(v8::Value* obj);
+
+  // TODO(dcarney): remove with deprecation of New functions.
+  enum NewStringType {
+    kNormalString = static_cast<int>(v8::NewStringType::kNormal),
+    kInternalizedString = static_cast<int>(v8::NewStringType::kInternalized)
+  };
+
+  /** Allocates a new string from UTF-8 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromUtf8(Isolate* isolate, const char* data,
+                                NewStringType type = kNormalString,
+                                int length = -1));
+
+  /** Allocates a new string from UTF-8 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromUtf8(
+      Isolate* isolate, const char* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from Latin-1 data.*/
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<String> NewFromOneByte(Isolate* isolate, const uint8_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from Latin-1 data.  Only returns an empty value
+   * when length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromOneByte(
+      Isolate* isolate, const uint8_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from UTF-16 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromTwoByte(Isolate* isolate, const uint16_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from UTF-16 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromTwoByte(
+      Isolate* isolate, const uint16_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /**
+   * Creates a new string by concatenating the left and the right strings
+   * passed in as parameters.
+   */
+  static Local<String> Concat(Local<String> left, Local<String> right);
+
+  /**
+   * Creates a new external string using the data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<String> NewExternal(
+                           Isolate* isolate, ExternalStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalTwoByte(
+      Isolate* isolate, ExternalStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalStringResource* resource);
+
+  /**
+   * Creates a new external string using the one-byte data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewExternal(Isolate* isolate,
+                                ExternalOneByteStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalOneByte(
+      Isolate* isolate, ExternalOneByteStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalOneByteStringResource* resource);
+
+  /**
+   * Returns true if this string can be made external.
+   */
+  bool CanMakeExternal();
+
+  /**
+   * Converts an object to a UTF-8-encoded character array.  Useful if
+   * you want to print the object.  If conversion to a string fails
+   * (e.g. due to an exception in the toString() method of the object)
+   * then the length() method returns 0 and the * operator returns
+   * NULL.
+   */
+  class V8_EXPORT Utf8Value {
+   public:
+    explicit Utf8Value(Local<v8::Value> obj);
+    ~Utf8Value();
+    char* operator*() { return str_; }
+    const char* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Utf8Value(const Utf8Value&) = delete;
+    void operator=(const Utf8Value&) = delete;
+
+   private:
+    char* str_;
+    int length_;
+  };
+
+  /**
+   * Converts an object to a two-byte (UTF-16-encoded) string.
+   * If conversion to a string fails (eg. due to an exception in the toString()
+   * method of the object) then the length() method returns 0 and the * operator
+   * returns NULL.
+   */
+  class V8_EXPORT Value {
+   public:
+    explicit Value(Local<v8::Value> obj);
+    ~Value();
+    uint16_t* operator*() { return str_; }
+    const uint16_t* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Value(const Value&) = delete;
+    void operator=(const Value&) = delete;
+
+   private:
+    uint16_t* str_;
+    int length_;
+  };
+
+ private:
+  void VerifyExternalStringResourceBase(ExternalStringResourceBase* v,
+                                        Encoding encoding) const;
+  void VerifyExternalStringResource(ExternalStringResource* val) const;
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript symbol (ECMA-262 edition 6)
+ */
+class V8_EXPORT Symbol : public Name {
+ public:
+  /**
+   * Returns the print name string of the symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a symbol. If name is not empty, it will be used as the description.
+   */
+  static Local<Symbol> New(Isolate* isolate,
+                           Local<String> name = Local<String>());
+
+  /**
+   * Access global symbol registry.
+   * Note that symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys.
+   */
+  static Local<Symbol> For(Isolate *isolate, Local<String> name);
+
+  /**
+   * Retrieve a global symbol. Similar to |For|, but using a separate
+   * registry that is not accessible by (and cannot clash with) JavaScript code.
+   */
+  static Local<Symbol> ForApi(Isolate *isolate, Local<String> name);
+
+  // Well-known symbols
+  static Local<Symbol> GetHasInstance(Isolate* isolate);
+  static Local<Symbol> GetIsConcatSpreadable(Isolate* isolate);
+  static Local<Symbol> GetIterator(Isolate* isolate);
+  static Local<Symbol> GetMatch(Isolate* isolate);
+  static Local<Symbol> GetReplace(Isolate* isolate);
+  static Local<Symbol> GetSearch(Isolate* isolate);
+  static Local<Symbol> GetSplit(Isolate* isolate);
+  static Local<Symbol> GetToPrimitive(Isolate* isolate);
+  static Local<Symbol> GetToStringTag(Isolate* isolate);
+  static Local<Symbol> GetUnscopables(Isolate* isolate);
+
+  V8_INLINE static Symbol* Cast(Value* obj);
+
+ private:
+  Symbol();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A private symbol
+ *
+ * This is an experimental feature. Use at your own risk.
+ */
+class V8_EXPORT Private : public Data {
+ public:
+  /**
+   * Returns the print name string of the private symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a private symbol. If name is not empty, it will be the description.
+   */
+  static Local<Private> New(Isolate* isolate,
+                            Local<String> name = Local<String>());
+
+  /**
+   * Retrieve a global private symbol. If a symbol with this name has not
+   * been retrieved in the same isolate before, it is created.
+   * Note that private symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys,
+   * e.g., "Class#property".
+   */
+  static Local<Private> ForApi(Isolate* isolate, Local<String> name);
+
+ private:
+  Private();
+};
+
+
+/**
+ * A JavaScript number value (ECMA-262, 4.3.20)
+ */
+class V8_EXPORT Number : public Primitive {
+ public:
+  double Value() const;
+  static Local<Number> New(Isolate* isolate, double value);
+  V8_INLINE static Number* Cast(v8::Value* obj);
+ private:
+  Number();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a signed integer.
+ */
+class V8_EXPORT Integer : public Number {
+ public:
+  static Local<Integer> New(Isolate* isolate, int32_t value);
+  static Local<Integer> NewFromUnsigned(Isolate* isolate, uint32_t value);
+  int64_t Value() const;
+  V8_INLINE static Integer* Cast(v8::Value* obj);
+ private:
+  Integer();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit signed integer.
+ */
+class V8_EXPORT Int32 : public Integer {
+ public:
+  int32_t Value() const;
+  V8_INLINE static Int32* Cast(v8::Value* obj);
+
+ private:
+  Int32();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit unsigned integer.
+ */
+class V8_EXPORT Uint32 : public Integer {
+ public:
+  uint32_t Value() const;
+  V8_INLINE static Uint32* Cast(v8::Value* obj);
+
+ private:
+  Uint32();
+  static void CheckCast(v8::Value* obj);
+};
+
+/**
+ * PropertyAttribute.
+ */
+enum PropertyAttribute {
+  /** None. **/
+  None = 0,
+  /** ReadOnly, i.e., not writable. **/
+  ReadOnly = 1 << 0,
+  /** DontEnum, i.e., not enumerable. **/
+  DontEnum = 1 << 1,
+  /** DontDelete, i.e., not configurable. **/
+  DontDelete = 1 << 2
+};
+
+/**
+ * Accessor[Getter|Setter] are used as callback functions when
+ * setting|getting a particular property. See Object and ObjectTemplate's
+ * method SetAccessor.
+ */
+typedef void (*AccessorGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+typedef void (*AccessorNameGetterCallback)(
+    Local<Name> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+typedef void (*AccessorSetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+typedef void (*AccessorNameSetterCallback)(
+    Local<Name> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+
+
+/**
+ * Access control specifications.
+ *
+ * Some accessors should be accessible across contexts.  These
+ * accessors have an explicit access control parameter which specifies
+ * the kind of cross-context access that should be allowed.
+ *
+ * TODO(dcarney): Remove PROHIBITS_OVERWRITING as it is now unused.
+ */
+enum AccessControl {
+  DEFAULT               = 0,
+  ALL_CAN_READ          = 1,
+  ALL_CAN_WRITE         = 1 << 1,
+  PROHIBITS_OVERWRITING = 1 << 2
+};
+
+/**
+ * Property filter bits. They can be or'ed to build a composite filter.
+ */
+enum PropertyFilter {
+  ALL_PROPERTIES = 0,
+  ONLY_WRITABLE = 1,
+  ONLY_ENUMERABLE = 2,
+  ONLY_CONFIGURABLE = 4,
+  SKIP_STRINGS = 8,
+  SKIP_SYMBOLS = 16
+};
+
+/**
+ * Keys/Properties filter enums:
+ *
+ * KeyCollectionMode limits the range of collected properties. kOwnOnly limits
+ * the collected properties to the given Object only. kIncludesPrototypes will
+ * include all keys of the objects's prototype chain as well.
+ */
+enum class KeyCollectionMode { kOwnOnly, kIncludePrototypes };
+
+/**
+ * kIncludesIndices allows for integer indices to be collected, while
+ * kSkipIndices will exclude integer indicies from being collected.
+ */
+enum class IndexFilter { kIncludeIndices, kSkipIndices };
+
+/**
+ * Integrity level for objects.
+ */
+enum class IntegrityLevel { kFrozen, kSealed };
+
+/**
+ * A JavaScript object (ECMA-262, 4.3.3)
+ */
+class V8_EXPORT Object : public Value {
+ public:
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(Local<Value> key, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context,
+                                        Local<Value> key, Local<Value> value);
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(uint32_t index, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index,
+                                        Local<Value> value);
+
+  // Implements CreateDataProperty (ECMA-262, 7.3.4).
+  //
+  // Defines a configurable, writable, enumerable property with the given value
+  // on the object unless the property already exists and is not configurable
+  // or the object is not extensible.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       Local<Name> key,
+                                                       Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       uint32_t index,
+                                                       Local<Value> value);
+
+  // Implements DefineOwnProperty.
+  //
+  // In general, CreateDataProperty will be faster, however, does not allow
+  // for specifying attributes.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineOwnProperty(
+      Local<Context> context, Local<Name> key, Local<Value> value,
+      PropertyAttribute attributes = None);
+
+  // Implements Object.DefineProperty(O, P, Attributes), see Ecma-262 19.1.2.4.
+  //
+  // The defineProperty function is used to add an own property or
+  // update the attributes of an existing own property of an object.
+  //
+  // Both data and accessor descriptors can be used.
+  //
+  // In general, CreateDataProperty is faster, however, does not allow
+  // for specifying attributes or an accessor descriptor.
+  //
+  // The PropertyDescriptor can change when redefining a property.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineProperty(
+      Local<Context> context, Local<Name> key, PropertyDescriptor& descriptor);
+
+  // Sets an own property on this object bypassing interceptors and
+  // overriding accessors or read-only properties.
+  //
+  // Note that if the object has an interceptor the property will be set
+  // locally, but since the interceptor takes precedence the local property
+  // will only be returned if the interceptor doesn't return a value.
+  //
+  // Note also that this only works for named properties.
+  V8_DEPRECATED("Use CreateDataProperty / DefineOwnProperty",
+                bool ForceSet(Local<Value> key, Local<Value> value,
+                              PropertyAttribute attribs = None));
+  V8_DEPRECATE_SOON("Use CreateDataProperty / DefineOwnProperty",
+                    Maybe<bool> ForceSet(Local<Context> context,
+                                         Local<Value> key, Local<Value> value,
+                                         PropertyAttribute attribs = None));
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(Local<Value> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(uint32_t index));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              uint32_t index);
+
+  /**
+   * Gets the property attributes of a property which can be None or
+   * any combination of ReadOnly, DontEnum and DontDelete. Returns
+   * None when the property doesn't exist.
+   */
+  V8_DEPRECATED("Use maybe version",
+                PropertyAttribute GetPropertyAttributes(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetPropertyAttributes(
+      Local<Context> context, Local<Value> key);
+
+  /**
+   * Returns Object.getOwnPropertyDescriptor as per ES2016 section 19.1.2.6.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetOwnPropertyDescriptor(Local<Name> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetOwnPropertyDescriptor(
+      Local<Context> context, Local<Name> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Has(Local<Value> key));
+  /**
+   * Object::Has() calls the abstract operation HasProperty(O, P) described
+   * in ECMA-262, 7.3.10. Has() returns
+   * true, if the object has the property, either own or on the prototype chain.
+   * Interceptors, i.e., PropertyQueryCallbacks, are called if present.
+   *
+   * Has() has the same side effects as JavaScript's `variable in object`.
+   * For example, calling Has() on a revoked proxy will throw an exception.
+   *
+   * \note Has() converts the key to a name, which possibly calls back into
+   * JavaScript.
+   *
+   * See also v8::Object::HasOwnProperty() and
+   * v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Delete(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  V8_DEPRECATED("Use maybe version", bool Has(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        uint32_t index);
+
+  V8_DEPRECATED("Use maybe version", bool Delete(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           uint32_t index);
+
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<String> name,
+                                 AccessorGetterCallback getter,
+                                 AccessorSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<Name> name,
+                                 AccessorNameGetterCallback getter,
+                                 AccessorNameSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetAccessor(Local<Context> context,
+                          Local<Name> name,
+                          AccessorNameGetterCallback getter,
+                          AccessorNameSetterCallback setter = 0,
+                          MaybeLocal<Value> data = MaybeLocal<Value>(),
+                          AccessControl settings = DEFAULT,
+                          PropertyAttribute attribute = None);
+
+  void SetAccessorProperty(Local<Name> name, Local<Function> getter,
+                           Local<Function> setter = Local<Function>(),
+                           PropertyAttribute attribute = None,
+                           AccessControl settings = DEFAULT);
+
+  /**
+   * Sets a native data property like Template::SetNativeDataProperty, but
+   * this method sets on this object directly.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetNativeDataProperty(
+      Local<Context> context, Local<Name> name,
+      AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = nullptr,
+      Local<Value> data = Local<Value>(), PropertyAttribute attributes = None);
+
+  /**
+   * Functionality for private properties.
+   * This is an experimental feature, use at your own risk.
+   * Note: Private properties are not inherited. Do not rely on this, since it
+   * may change.
+   */
+  Maybe<bool> HasPrivate(Local<Context> context, Local<Private> key);
+  Maybe<bool> SetPrivate(Local<Context> context, Local<Private> key,
+                         Local<Value> value);
+  Maybe<bool> DeletePrivate(Local<Context> context, Local<Private> key);
+  MaybeLocal<Value> GetPrivate(Local<Context> context, Local<Private> key);
+
+  /**
+   * Returns an array containing the names of the enumerable properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context, KeyCollectionMode mode,
+      PropertyFilter property_filter, IndexFilter index_filter);
+
+  /**
+   * This function has the same functionality as GetPropertyNames but
+   * the returned array doesn't contain the names of properties from
+   * prototype objects.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetOwnPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context);
+
+  /**
+   * Returns an array containing the names of the filtered properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context, PropertyFilter filter);
+
+  /**
+   * Get the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  Local<Value> GetPrototype();
+
+  /**
+   * Set the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  V8_DEPRECATED("Use maybe version", bool SetPrototype(Local<Value> prototype));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetPrototype(Local<Context> context,
+                                                 Local<Value> prototype);
+
+  /**
+   * Finds an instance of the given function template in the prototype
+   * chain.
+   */
+  Local<Object> FindInstanceInPrototypeChain(Local<FunctionTemplate> tmpl);
+
+  /**
+   * Call builtin Object.prototype.toString on this object.
+   * This is different from Value::ToString() that may call
+   * user-defined toString function. This one does not.
+   */
+  V8_DEPRECATED("Use maybe version", Local<String> ObjectProtoToString());
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ObjectProtoToString(
+      Local<Context> context);
+
+  /**
+   * Returns the name of the function invoked as a constructor for this object.
+   */
+  Local<String> GetConstructorName();
+
+  /**
+   * Sets the integrity level of the object.
+   */
+  Maybe<bool> SetIntegrityLevel(Local<Context> context, IntegrityLevel level);
+
+  /** Gets the number of internal fields for this Object. */
+  int InternalFieldCount();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static int InternalFieldCount(
+      const PersistentBase<Object>& object) {
+    return object.val_->InternalFieldCount();
+  }
+
+  /** Gets the value from an internal field. */
+  V8_INLINE Local<Value> GetInternalField(int index);
+
+  /** Sets the value in an internal field. */
+  void SetInternalField(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from an internal field. This field
+   * must have been set by SetAlignedPointerInInternalField, everything else
+   * leads to undefined behavior.
+   */
+  V8_INLINE void* GetAlignedPointerFromInternalField(int index);
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static void* GetAlignedPointerFromInternalField(
+      const PersistentBase<Object>& object, int index) {
+    return object.val_->GetAlignedPointerFromInternalField(index);
+  }
+
+  /**
+   * Sets a 2-byte-aligned native pointer in an internal field. To retrieve such
+   * a field, GetAlignedPointerFromInternalField must be used, everything else
+   * leads to undefined behavior.
+   */
+  void SetAlignedPointerInInternalField(int index, void* value);
+  void SetAlignedPointerInInternalFields(int argc, int indices[],
+                                         void* values[]);
+
+  // Testers for local properties.
+  V8_DEPRECATED("Use maybe version", bool HasOwnProperty(Local<String> key));
+
+  /**
+   * HasOwnProperty() is like JavaScript's Object.prototype.hasOwnProperty().
+   *
+   * See also v8::Object::Has() and v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   Local<Name> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedProperty(Local<String> key));
+  /**
+   * Use HasRealNamedProperty() if you want to check if an object has an own
+   * property without causing side effects, i.e., without calling interceptors.
+   *
+   * This function is similar to v8::Object::HasOwnProperty(), but it does not
+   * call interceptors.
+   *
+   * \note Consider using non-masking interceptors, i.e., the interceptors are
+   * not called if the receiver has the real named property. See
+   * `v8::PropertyHandlerFlags::kNonMasking`.
+   *
+   * See also v8::Object::Has().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedProperty(Local<Context> context,
+                                                         Local<Name> key);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealIndexedProperty(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealIndexedProperty(
+      Local<Context> context, uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedCallbackProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedCallbackProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Local<Value> GetRealNamedPropertyInPrototypeChain(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedPropertyInPrototypeChain(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property in the prototype chain,
+   * which can be None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Maybe<PropertyAttribute> GetRealNamedPropertyAttributesInPrototypeChain(
+          Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute>
+  GetRealNamedPropertyAttributesInPrototypeChain(Local<Context> context,
+                                                 Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located on the object or
+   * in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetRealNamedProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property which can be
+   * None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+                    Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+      Local<Context> context, Local<Name> key);
+
+  /** Tests for a named lookup interceptor.*/
+  bool HasNamedLookupInterceptor();
+
+  /** Tests for an index lookup interceptor.*/
+  bool HasIndexedLookupInterceptor();
+
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses a hidden property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  /**
+   * Clone this object with a fast but shallow copy.  Values will point
+   * to the same values as the original object.
+   */
+  // TODO(dcarney): take an isolate and optionally bail out?
+  Local<Object> Clone();
+
+  /**
+   * Returns the context in which the object was created.
+   */
+  Local<Context> CreationContext();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static Local<Context> CreationContext(
+      const PersistentBase<Object>& object) {
+    return object.val_->CreationContext();
+  }
+
+  /**
+   * Checks whether a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * When an Object is callable this method returns true.
+   */
+  bool IsCallable();
+
+  /**
+   * True if this object is a constructor.
+   */
+  bool IsConstructor();
+
+  /**
+   * Call an Object as a function if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsFunction(Local<Value> recv, int argc,
+                                            Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsFunction(Local<Context> context,
+                                                         Local<Value> recv,
+                                                         int argc,
+                                                         Local<Value> argv[]);
+
+  /**
+   * Call an Object as a constructor if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * Note: This method behaves like the Function::NewInstance method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsConstructor(int argc, Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsConstructor(
+      Local<Context> context, int argc, Local<Value> argv[]);
+
+  /**
+   * Return the isolate to which the Object belongs to.
+   */
+  V8_DEPRECATE_SOON("Keep track of isolate correctly", Isolate* GetIsolate());
+
+  static Local<Object> New(Isolate* isolate);
+
+  V8_INLINE static Object* Cast(Value* obj);
+
+ private:
+  Object();
+  static void CheckCast(Value* obj);
+  Local<Value> SlowGetInternalField(int index);
+  void* SlowGetAlignedPointerFromInternalField(int index);
+};
+
+
+/**
+ * An instance of the built-in array constructor (ECMA-262, 15.4.2).
+ */
+class V8_EXPORT Array : public Object {
+ public:
+  uint32_t Length() const;
+
+  /**
+   * Clones an element at index |index|.  Returns an empty
+   * handle if cloning fails (for any reason).
+   */
+  V8_DEPRECATED("Cloning is not supported.",
+                Local<Object> CloneElementAt(uint32_t index));
+  V8_DEPRECATED("Cloning is not supported.",
+                MaybeLocal<Object> CloneElementAt(Local<Context> context,
+                                                  uint32_t index));
+
+  /**
+   * Creates a JavaScript array with the given length. If the length
+   * is negative the returned array will have length 0.
+   */
+  static Local<Array> New(Isolate* isolate, int length = 0);
+
+  V8_INLINE static Array* Cast(Value* obj);
+ private:
+  Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Map constructor (ECMA-262, 6th Edition, 23.1.1).
+ */
+class V8_EXPORT Map : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Map> Set(Local<Context> context,
+                                            Local<Value> key,
+                                            Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of length Size() * 2, where index N is the Nth key and
+   * index N + 1 is the Nth value.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Map.
+   */
+  static Local<Map> New(Isolate* isolate);
+
+  V8_INLINE static Map* Cast(Value* obj);
+
+ private:
+  Map();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Set constructor (ECMA-262, 6th Edition, 23.2.1).
+ */
+class V8_EXPORT Set : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Set> Add(Local<Context> context,
+                                            Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of the keys in this Set.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Set.
+   */
+  static Local<Set> New(Isolate* isolate);
+
+  V8_INLINE static Set* Cast(Value* obj);
+
+ private:
+  Set();
+  static void CheckCast(Value* obj);
+};
+
+
+template<typename T>
+class ReturnValue {
+ public:
+  template <class S> V8_INLINE ReturnValue(const ReturnValue<S>& that)
+      : value_(that.value_) {
+    TYPE_CHECK(T, S);
+  }
+  // Local setters
+  template <typename S>
+  V8_INLINE V8_DEPRECATE_SOON("Use Global<> instead",
+                              void Set(const Persistent<S>& handle));
+  template <typename S>
+  V8_INLINE void Set(const Global<S>& handle);
+  template <typename S>
+  V8_INLINE void Set(const Local<S> handle);
+  // Fast primitive setters
+  V8_INLINE void Set(bool value);
+  V8_INLINE void Set(double i);
+  V8_INLINE void Set(int32_t i);
+  V8_INLINE void Set(uint32_t i);
+  // Fast JS primitive setters
+  V8_INLINE void SetNull();
+  V8_INLINE void SetUndefined();
+  V8_INLINE void SetEmptyString();
+  // Convenience getter for Isolate
+  V8_INLINE Isolate* GetIsolate() const;
+
+  // Pointer setter: Uncompilable to prevent inadvertent misuse.
+  template <typename S>
+  V8_INLINE void Set(S* whatever);
+
+  // Getter. Creates a new Local<> so it comes with a certain performance
+  // hit. If the ReturnValue was not yet set, this will return the undefined
+  // value.
+  V8_INLINE Local<Value> Get() const;
+
+ private:
+  template<class F> friend class ReturnValue;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  template <class F, class G, class H>
+  friend class PersistentValueMapBase;
+  V8_INLINE void SetInternal(internal::Object* value) { *value_ = value; }
+  V8_INLINE internal::Object* GetDefaultValue();
+  V8_INLINE explicit ReturnValue(internal::Object** slot);
+  internal::Object** value_;
+};
+
+
+/**
+ * The argument information given to function call callbacks.  This
+ * class provides access to information about the context of the call,
+ * including the receiver, the number and values of arguments, and
+ * the holder of the function.
+ */
+template<typename T>
+class FunctionCallbackInfo {
+ public:
+  /** The number of available arguments. */
+  V8_INLINE int Length() const;
+  /** Accessor for the available arguments. */
+  V8_INLINE Local<Value> operator[](int i) const;
+  V8_INLINE V8_DEPRECATED("Use Data() to explicitly pass Callee instead",
+                          Local<Function> Callee() const);
+  /** Returns the receiver. This corresponds to the "this" value. */
+  V8_INLINE Local<Object> This() const;
+  /**
+   * If the callback was created without a Signature, this is the same
+   * value as This(). If there is a signature, and the signature didn't match
+   * This() but one of its hidden prototypes, this will be the respective
+   * hidden prototype.
+   *
+   * Note that this is not the prototype of This() on which the accessor
+   * referencing this callback was found (which in V8 internally is often
+   * referred to as holder [sic]).
+   */
+  V8_INLINE Local<Object> Holder() const;
+  /** For construct calls, this returns the "new.target" value. */
+  V8_INLINE Local<Value> NewTarget() const;
+  /** Indicates whether this is a regular call or a construct call. */
+  V8_INLINE bool IsConstructCall() const;
+  /** The data argument specified when creating the callback. */
+  V8_INLINE Local<Value> Data() const;
+  /** The current Isolate. */
+  V8_INLINE Isolate* GetIsolate() const;
+  /** The ReturnValue for the call. */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 8;
+
+ protected:
+  friend class internal::FunctionCallbackArguments;
+  friend class internal::CustomArguments<FunctionCallbackInfo>;
+  friend class debug::ConsoleCallArguments;
+  static const int kHolderIndex = 0;
+  static const int kIsolateIndex = 1;
+  static const int kReturnValueDefaultValueIndex = 2;
+  static const int kReturnValueIndex = 3;
+  static const int kDataIndex = 4;
+  static const int kCalleeIndex = 5;
+  static const int kContextSaveIndex = 6;
+  static const int kNewTargetIndex = 7;
+
+  V8_INLINE FunctionCallbackInfo(internal::Object** implicit_args,
+                                 internal::Object** values, int length);
+  internal::Object** implicit_args_;
+  internal::Object** values_;
+  int length_;
+};
+
+
+/**
+ * The information passed to a property callback about the context
+ * of the property access.
+ */
+template<typename T>
+class PropertyCallbackInfo {
+ public:
+  /**
+   * \return The isolate of the property access.
+   */
+  V8_INLINE Isolate* GetIsolate() const;
+
+  /**
+   * \return The data set in the configuration, i.e., in
+   * `NamedPropertyHandlerConfiguration` or
+   * `IndexedPropertyHandlerConfiguration.`
+   */
+  V8_INLINE Local<Value> Data() const;
+
+  /**
+   * \return The receiver. In many cases, this is the object on which the
+   * property access was intercepted. When using
+   * `Reflect.get`, `Function.prototype.call`, or similar functions, it is the
+   * object passed in as receiver or thisArg.
+   *
+   * \code
+   *  void GetterCallback(Local<Name> name,
+   *                      const v8::PropertyCallbackInfo<v8::Value>& info) {
+   *     auto context = info.GetIsolate()->GetCurrentContext();
+   *
+   *     v8::Local<v8::Value> a_this =
+   *         info.This()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *     v8::Local<v8::Value> a_holder =
+   *         info.Holder()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *
+   *    CHECK(v8_str("r")->Equals(context, a_this).FromJust());
+   *    CHECK(v8_str("obj")->Equals(context, a_holder).FromJust());
+   *
+   *    info.GetReturnValue().Set(name);
+   *  }
+   *
+   *  v8::Local<v8::FunctionTemplate> templ =
+   *  v8::FunctionTemplate::New(isolate);
+   *  templ->InstanceTemplate()->SetHandler(
+   *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+   *  LocalContext env;
+   *  env->Global()
+   *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+   *                                           .ToLocalChecked()
+   *                                           ->NewInstance(env.local())
+   *                                           .ToLocalChecked())
+   *      .FromJust();
+   *
+   *  CompileRun("obj.a = 'obj'; var r = {a: 'r'}; Reflect.get(obj, 'x', r)");
+   * \endcode
+   */
+  V8_INLINE Local<Object> This() const;
+
+  /**
+   * \return The object in the prototype chain of the receiver that has the
+   * interceptor. Suppose you have `x` and its prototype is `y`, and `y`
+   * has an interceptor. Then `info.This()` is `x` and `info.Holder()` is `y`.
+   * The Holder() could be a hidden object (the global object, rather
+   * than the global proxy).
+   *
+   * \note For security reasons, do not pass the object back into the runtime.
+   */
+  V8_INLINE Local<Object> Holder() const;
+
+  /**
+   * \return The return value of the callback.
+   * Can be changed by calling Set().
+   * \code
+   * info.GetReturnValue().Set(...)
+   * \endcode
+   *
+   */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+
+  /**
+   * \return True if the intercepted function should throw if an error occurs.
+   * Usually, `true` corresponds to `'use strict'`.
+   *
+   * \note Always `false` when intercepting `Reflect.set()`
+   * independent of the language mode.
+   */
+  V8_INLINE bool ShouldThrowOnError() const;
+
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 7;
+
+ protected:
+  friend class MacroAssembler;
+  friend class internal::PropertyCallbackArguments;
+  friend class internal::CustomArguments<PropertyCallbackInfo>;
+  static const int kShouldThrowOnErrorIndex = 0;
+  static const int kHolderIndex = 1;
+  static const int kIsolateIndex = 2;
+  static const int kReturnValueDefaultValueIndex = 3;
+  static const int kReturnValueIndex = 4;
+  static const int kDataIndex = 5;
+  static const int kThisIndex = 6;
+
+  V8_INLINE PropertyCallbackInfo(internal::Object** args) : args_(args) {}
+  internal::Object** args_;
+};
+
+
+typedef void (*FunctionCallback)(const FunctionCallbackInfo<Value>& info);
+
+enum class ConstructorBehavior { kThrow, kAllow };
+
+/**
+ * A JavaScript function object (ECMA-262, 15.3).
+ */
+class V8_EXPORT Function : public Object {
+ public:
+  /**
+   * Create a function in the current execution context
+   * for a given FunctionCallback.
+   */
+  static MaybeLocal<Function> New(
+      Local<Context> context, FunctionCallback callback,
+      Local<Value> data = Local<Value>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Function> New(Isolate* isolate, FunctionCallback callback,
+                          Local<Value> data = Local<Value>(), int length = 0));
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Object> NewInstance(int argc, Local<Value> argv[]) const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context, int argc, Local<Value> argv[]) const;
+
+  V8_DEPRECATED("Use maybe version", Local<Object> NewInstance() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context) const {
+    return NewInstance(context, 0, nullptr);
+  }
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Value> Call(Local<Value> recv, int argc,
+                                      Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Call(Local<Context> context,
+                                               Local<Value> recv, int argc,
+                                               Local<Value> argv[]);
+
+  void SetName(Local<String> name);
+  Local<Value> GetName() const;
+
+  /**
+   * Name inferred from variable or property assignment of this function.
+   * Used to facilitate debugging and profiling of JavaScript code written
+   * in an OO style, where many functions are anonymous but are assigned
+   * to object properties.
+   */
+  Local<Value> GetInferredName() const;
+
+  /**
+   * displayName if it is set, otherwise name if it is configured, otherwise
+   * function name, otherwise inferred name.
+   */
+  Local<Value> GetDebugName() const;
+
+  /**
+   * User-defined name assigned to the "displayName" property of this function.
+   * Used to facilitate debugging and profiling of JavaScript code.
+   */
+  Local<Value> GetDisplayName() const;
+
+  /**
+   * Returns zero based line number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptLineNumber() const;
+  /**
+   * Returns zero based column number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptColumnNumber() const;
+
+  /**
+   * Tells whether this function is builtin.
+   */
+  V8_DEPRECATED("this should no longer be used.", bool IsBuiltin() const);
+
+  /**
+   * Returns scriptId.
+   */
+  int ScriptId() const;
+
+  /**
+   * Returns the original function if this function is bound, else returns
+   * v8::Undefined.
+   */
+  Local<Value> GetBoundFunction() const;
+
+  ScriptOrigin GetScriptOrigin() const;
+  V8_INLINE static Function* Cast(Value* obj);
+  static const int kLineOffsetNotFound;
+
+ private:
+  Function();
+  static void CheckCast(Value* obj);
+};
+
+#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
+#endif
+
+/**
+ * An instance of the built-in Promise constructor (ES6 draft).
+ */
+class V8_EXPORT Promise : public Object {
+ public:
+  /**
+   * State of the promise. Each value corresponds to one of the possible values
+   * of the [[PromiseState]] field.
+   */
+  enum PromiseState { kPending, kFulfilled, kRejected };
+
+  class V8_EXPORT Resolver : public Object {
+   public:
+    /**
+     * Create a new resolver, along with an associated promise in pending state.
+     */
+    static V8_DEPRECATE_SOON("Use maybe version",
+                             Local<Resolver> New(Isolate* isolate));
+    static V8_WARN_UNUSED_RESULT MaybeLocal<Resolver> New(
+        Local<Context> context);
+
+    /**
+     * Extract the associated promise.
+     */
+    Local<Promise> GetPromise();
+
+    /**
+     * Resolve/reject the associated promise with a given value.
+     * Ignored if the promise is no longer pending.
+     */
+    V8_DEPRECATE_SOON("Use maybe version", void Resolve(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Resolve(Local<Context> context,
+                                              Local<Value> value);
+
+    V8_DEPRECATE_SOON("Use maybe version", void Reject(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Reject(Local<Context> context,
+                                             Local<Value> value);
+
+    V8_INLINE static Resolver* Cast(Value* obj);
+
+   private:
+    Resolver();
+    static void CheckCast(Value* obj);
+  };
+
+  /**
+   * Register a resolution/rejection handler with a promise.
+   * The handler is given the respective resolution/rejection value as
+   * an argument. If the promise is already resolved/rejected, the handler is
+   * invoked at the end of turn.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Catch(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Catch(Local<Context> context,
+                                                  Local<Function> handler);
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Then(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
+                                                 Local<Function> handler);
+
+  /**
+   * Returns true if the promise has at least one derived promise, and
+   * therefore resolve/reject handlers (including default handler).
+   */
+  bool HasHandler();
+
+  /**
+   * Returns the content of the [[PromiseResult]] field. The Promise must not
+   * be pending.
+   */
+  Local<Value> Result();
+
+  /**
+   * Returns the value of the [[PromiseState]] field.
+   */
+  PromiseState State();
+
+  V8_INLINE static Promise* Cast(Value* obj);
+
+  static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
+
+ private:
+  Promise();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of a Property Descriptor, see Ecma-262 6.2.4.
+ *
+ * Properties in a descriptor are present or absent. If you do not set
+ * `enumerable`, `configurable`, and `writable`, they are absent. If `value`,
+ * `get`, or `set` are absent, but you must specify them in the constructor, use
+ * empty handles.
+ *
+ * Accessors `get` and `set` must be callable or undefined if they are present.
+ *
+ * \note Only query properties if they are present, i.e., call `x()` only if
+ * `has_x()` returns true.
+ *
+ * \code
+ * // var desc = {writable: false}
+ * v8::PropertyDescriptor d(Local<Value>()), false);
+ * d.value(); // error, value not set
+ * if (d.has_writable()) {
+ *   d.writable(); // false
+ * }
+ *
+ * // var desc = {value: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate));
+ *
+ * // var desc = {get: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate), Local<Value>()));
+ * \endcode
+ */
+class V8_EXPORT PropertyDescriptor {
+ public:
+  // GenericDescriptor
+  PropertyDescriptor();
+
+  // DataDescriptor
+  PropertyDescriptor(Local<Value> value);
+
+  // DataDescriptor with writable property
+  PropertyDescriptor(Local<Value> value, bool writable);
+
+  // AccessorDescriptor
+  PropertyDescriptor(Local<Value> get, Local<Value> set);
+
+  ~PropertyDescriptor();
+
+  Local<Value> value() const;
+  bool has_value() const;
+
+  Local<Value> get() const;
+  bool has_get() const;
+  Local<Value> set() const;
+  bool has_set() const;
+
+  void set_enumerable(bool enumerable);
+  bool enumerable() const;
+  bool has_enumerable() const;
+
+  void set_configurable(bool configurable);
+  bool configurable() const;
+  bool has_configurable() const;
+
+  bool writable() const;
+  bool has_writable() const;
+
+  struct PrivateData;
+  PrivateData* get_private() const { return private_; }
+
+  PropertyDescriptor(const PropertyDescriptor&) = delete;
+  void operator=(const PropertyDescriptor&) = delete;
+
+ private:
+  PrivateData* private_;
+};
+
+/**
+ * An instance of the built-in Proxy constructor (ECMA-262, 6th Edition,
+ * 26.2.1).
+ */
+class V8_EXPORT Proxy : public Object {
+ public:
+  Local<Object> GetTarget();
+  Local<Value> GetHandler();
+  bool IsRevoked();
+  void Revoke();
+
+  /**
+   * Creates a new Proxy for the target object.
+   */
+  static MaybeLocal<Proxy> New(Local<Context> context,
+                               Local<Object> local_target,
+                               Local<Object> local_handler);
+
+  V8_INLINE static Proxy* Cast(Value* obj);
+
+ private:
+  Proxy();
+  static void CheckCast(Value* obj);
+};
+
+// TODO(mtrofin): rename WasmCompiledModule to WasmModuleObject, for
+// consistency with internal APIs.
+class V8_EXPORT WasmCompiledModule : public Object {
+ public:
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> SerializedModule;
+  // A buffer that is owned by the caller.
+  typedef std::pair<const uint8_t*, size_t> CallerOwnedBuffer;
+
+  // An opaque, native heap object for transferring wasm modules. It
+  // supports move semantics, and does not support copy semantics.
+  class TransferrableModule final {
+   public:
+    TransferrableModule(TransferrableModule&& src) = default;
+    TransferrableModule(const TransferrableModule& src) = delete;
+
+    TransferrableModule& operator=(TransferrableModule&& src) = default;
+    TransferrableModule& operator=(const TransferrableModule& src) = delete;
+
+   private:
+    typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> OwnedBuffer;
+    friend class WasmCompiledModule;
+    TransferrableModule(OwnedBuffer&& code, OwnedBuffer&& bytes)
+        : compiled_code(std::move(code)), wire_bytes(std::move(bytes)) {}
+
+    OwnedBuffer compiled_code = {nullptr, 0};
+    OwnedBuffer wire_bytes = {nullptr, 0};
+  };
+
+  // Get an in-memory, non-persistable, and context-independent (meaning,
+  // suitable for transfer to another Isolate and Context) representation
+  // of this wasm compiled module.
+  TransferrableModule GetTransferrableModule();
+
+  // Efficiently re-create a WasmCompiledModule, without recompiling, from
+  // a TransferrableModule.
+  static MaybeLocal<WasmCompiledModule> FromTransferrableModule(
+      Isolate* isolate, const TransferrableModule&);
+
+  // Get the wasm-encoded bytes that were used to compile this module.
+  Local<String> GetWasmWireBytes();
+
+  // Serialize the compiled module. The serialized data does not include the
+  // uncompiled bytes.
+  SerializedModule Serialize();
+
+  // If possible, deserialize the module, otherwise compile it from the provided
+  // uncompiled bytes.
+  static MaybeLocal<WasmCompiledModule> DeserializeOrCompile(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  V8_INLINE static WasmCompiledModule* Cast(Value* obj);
+
+ private:
+  // TODO(ahaas): please remove the friend once streamed compilation is
+  // implemented
+  friend class WasmModuleObjectBuilder;
+
+  static MaybeLocal<WasmCompiledModule> Deserialize(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  static MaybeLocal<WasmCompiledModule> Compile(Isolate* isolate,
+                                                const uint8_t* start,
+                                                size_t length);
+  static CallerOwnedBuffer AsCallerOwned(
+      const TransferrableModule::OwnedBuffer& buff) {
+    return {buff.first.get(), buff.second};
+  }
+
+  WasmCompiledModule();
+  static void CheckCast(Value* obj);
+};
+
+class V8_EXPORT WasmModuleObjectBuilder final {
+ public:
+  WasmModuleObjectBuilder(Isolate* isolate) : isolate_(isolate) {}
+  // The buffer passed into OnBytesReceived is owned by the caller.
+  void OnBytesReceived(const uint8_t*, size_t size);
+  MaybeLocal<WasmCompiledModule> Finish();
+
+ private:
+  Isolate* isolate_ = nullptr;
+  // TODO(ahaas): We probably need none of this below here once streamed
+  // compilation is implemented.
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> Buffer;
+
+  // Disable copy semantics *in this implementation*. We can choose to
+  // relax this, albeit it's not clear why.
+  WasmModuleObjectBuilder(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder(WasmModuleObjectBuilder&&) = default;
+  WasmModuleObjectBuilder& operator=(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder& operator=(WasmModuleObjectBuilder&&) = default;
+
+  std::vector<Buffer> received_buffers_;
+  size_t total_size_ = 0;
+};
+
+#ifndef V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+enum class ArrayBufferCreationMode { kInternalized, kExternalized };
+
+
+/**
+ * An instance of the built-in ArrayBuffer constructor (ES6 draft 15.13.5).
+ */
+class V8_EXPORT ArrayBuffer : public Object {
+ public:
+  /**
+   * A thread-safe allocator that V8 uses to allocate |ArrayBuffer|'s memory.
+   * The allocator is a global V8 setting. It has to be set via
+   * Isolate::CreateParams.
+   *
+   * Memory allocated through this allocator by V8 is accounted for as external
+   * memory by V8. Note that V8 keeps track of the memory for all internalized
+   * |ArrayBuffer|s. Responsibility for tracking external memory (using
+   * Isolate::AdjustAmountOfExternalAllocatedMemory) is handed over to the
+   * embedder upon externalization and taken over upon internalization (creating
+   * an internalized buffer from an existing buffer).
+   *
+   * Note that it is unsafe to call back into V8 from any of the allocator
+   * functions.
+   */
+  class V8_EXPORT Allocator { // NOLINT
+   public:
+    virtual ~Allocator() {}
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory should be initialized to zeroes.
+     */
+    virtual void* Allocate(size_t length) = 0;
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory does not have to be initialized.
+     */
+    virtual void* AllocateUninitialized(size_t length) = 0;
+
+    /**
+     * Reserved |length| bytes, but do not commit the memory. Must call
+     * |SetProtection| to make memory accessible.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void* Reserve(size_t length);
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate|.
+     */
+    virtual void Free(void* data, size_t length) = 0;
+
+    enum class AllocationMode { kNormal, kReservation };
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate| or
+     * |Reserve|, depending on |mode|.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void Free(void* data, size_t length, AllocationMode mode);
+
+    enum class Protection { kNoAccess, kReadWrite };
+
+    /**
+     * Change the protection on a region of memory.
+     *
+     * On platforms that make a distinction between reserving and committing
+     * memory, changing the protection to kReadWrite must also ensure the memory
+     * is committed.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void SetProtection(void* data, size_t length,
+                               Protection protection);
+
+    /**
+     * malloc/free based convenience allocator.
+     *
+     * Caller takes ownership, i.e. the returned object needs to be freed using
+     * |delete allocator| once it is no longer in use.
+     */
+    static Allocator* NewDefaultAllocator();
+  };
+
+  /**
+   * The contents of an |ArrayBuffer|. Externalization of |ArrayBuffer|
+   * returns an instance of this class, populated, with a pointer to data
+   * and byte length.
+   *
+   * The Data pointer of ArrayBuffer::Contents is always allocated with
+   * Allocator::Allocate that is set via Isolate::CreateParams.
+   */
+  class V8_EXPORT Contents { // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class ArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new ArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created ArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<ArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new ArrayBuffer over an existing memory block.
+   * The created array buffer is by default immediately in externalized state.
+   * In externalized state, the memory block will not be reclaimed when a
+   * created ArrayBuffer is garbage-collected.
+   * In internalized state, the memory block will be released using
+   * |Allocator::Free| once all ArrayBuffers referencing it are collected by
+   * the garbage collector.
+   */
+  static Local<ArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if ArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this ArrayBuffer may be neutered.
+   */
+  bool IsNeuterable() const;
+
+  /**
+   * Neuters this ArrayBuffer and all its views (typed arrays).
+   * Neutering sets the byte length of the buffer and all typed arrays to zero,
+   * preventing JavaScript from ever accessing underlying backing store.
+   * ArrayBuffer should have been externalized and must be neuterable.
+   */
+  void Neuter();
+
+  /**
+   * Make this ArrayBuffer external. The pointer to underlying memory block
+   * and byte length are returned as |Contents| structure. After ArrayBuffer
+   * had been externalized, it does no longer own the memory block. The caller
+   * should take steps to free memory when it is no longer needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * that has been set via Isolate::CreateParams.
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer gets garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|.
+   */
+  Contents GetContents();
+
+  V8_INLINE static ArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+#ifndef V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+/**
+ * A base class for an instance of one of "views" over ArrayBuffer,
+ * including TypedArrays and DataView (ES6 draft 15.13).
+ */
+class V8_EXPORT ArrayBufferView : public Object {
+ public:
+  /**
+   * Returns underlying ArrayBuffer.
+   */
+  Local<ArrayBuffer> Buffer();
+  /**
+   * Byte offset in |Buffer|.
+   */
+  size_t ByteOffset();
+  /**
+   * Size of a view in bytes.
+   */
+  size_t ByteLength();
+
+  /**
+   * Copy the contents of the ArrayBufferView's buffer to an embedder defined
+   * memory without additional overhead that calling ArrayBufferView::Buffer
+   * might incur.
+   *
+   * Will write at most min(|byte_length|, ByteLength) bytes starting at
+   * ByteOffset of the underlying buffer to the memory starting at |dest|.
+   * Returns the number of bytes actually written.
+   */
+  size_t CopyContents(void* dest, size_t byte_length);
+
+  /**
+   * Returns true if ArrayBufferView's backing ArrayBuffer has already been
+   * allocated.
+   */
+  bool HasBuffer() const;
+
+  V8_INLINE static ArrayBufferView* Cast(Value* obj);
+
+  static const int kInternalFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBufferView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A base class for an instance of TypedArray series of constructors
+ * (ES6 draft 15.13.6).
+ */
+class V8_EXPORT TypedArray : public ArrayBufferView {
+ public:
+  /**
+   * Number of elements in this typed array
+   * (e.g. for Int16Array, |ByteLength|/2).
+   */
+  size_t Length();
+
+  V8_INLINE static TypedArray* Cast(Value* obj);
+
+ private:
+  TypedArray();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8Array : public TypedArray {
+ public:
+  static Local<Uint8Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Uint8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Uint8Array* Cast(Value* obj);
+
+ private:
+  Uint8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8ClampedArray constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8ClampedArray : public TypedArray {
+ public:
+  static Local<Uint8ClampedArray> New(Local<ArrayBuffer> array_buffer,
+                                      size_t byte_offset, size_t length);
+  static Local<Uint8ClampedArray> New(
+      Local<SharedArrayBuffer> shared_array_buffer, size_t byte_offset,
+      size_t length);
+  V8_INLINE static Uint8ClampedArray* Cast(Value* obj);
+
+ private:
+  Uint8ClampedArray();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of Int8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int8Array : public TypedArray {
+ public:
+  static Local<Int8Array> New(Local<ArrayBuffer> array_buffer,
+                              size_t byte_offset, size_t length);
+  static Local<Int8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                              size_t byte_offset, size_t length);
+  V8_INLINE static Int8Array* Cast(Value* obj);
+
+ private:
+  Int8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint16Array : public TypedArray {
+ public:
+  static Local<Uint16Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint16Array* Cast(Value* obj);
+
+ private:
+  Uint16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int16Array : public TypedArray {
+ public:
+  static Local<Int16Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int16Array* Cast(Value* obj);
+
+ private:
+  Int16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint32Array : public TypedArray {
+ public:
+  static Local<Uint32Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint32Array* Cast(Value* obj);
+
+ private:
+  Uint32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int32Array : public TypedArray {
+ public:
+  static Local<Int32Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int32Array* Cast(Value* obj);
+
+ private:
+  Int32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float32Array : public TypedArray {
+ public:
+  static Local<Float32Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float32Array* Cast(Value* obj);
+
+ private:
+  Float32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float64Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float64Array : public TypedArray {
+ public:
+  static Local<Float64Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float64Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float64Array* Cast(Value* obj);
+
+ private:
+  Float64Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of DataView constructor (ES6 draft 15.13.7).
+ */
+class V8_EXPORT DataView : public ArrayBufferView {
+ public:
+  static Local<DataView> New(Local<ArrayBuffer> array_buffer,
+                             size_t byte_offset, size_t length);
+  static Local<DataView> New(Local<SharedArrayBuffer> shared_array_buffer,
+                             size_t byte_offset, size_t length);
+  V8_INLINE static DataView* Cast(Value* obj);
+
+ private:
+  DataView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in SharedArrayBuffer constructor.
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedArrayBuffer : public Object {
+ public:
+  /**
+   * The contents of an |SharedArrayBuffer|. Externalization of
+   * |SharedArrayBuffer| returns an instance of this class, populated, with a
+   * pointer to data and byte length.
+   *
+   * The Data pointer of SharedArrayBuffer::Contents is always allocated with
+   * |ArrayBuffer::Allocator::Allocate| by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   * This API is experimental and may change significantly.
+   */
+  class V8_EXPORT Contents {  // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class SharedArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new SharedArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created SharedArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<SharedArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new SharedArrayBuffer over an existing memory block.  The created
+   * array buffer is immediately in externalized state unless otherwise
+   * specified. The memory block will not be reclaimed when a created
+   * SharedArrayBuffer is garbage-collected.
+   */
+  static Local<SharedArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if SharedArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Make this SharedArrayBuffer external. The pointer to underlying memory
+   * block and byte length are returned as |Contents| structure. After
+   * SharedArrayBuffer had been externalized, it does no longer own the memory
+   * block. The caller should take steps to free memory when it is no longer
+   * needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer became garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   */
+  Contents GetContents();
+
+  V8_INLINE static SharedArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  SharedArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Date constructor (ECMA-262, 15.9).
+ */
+class V8_EXPORT Date : public Object {
+ public:
+  static V8_DEPRECATE_SOON("Use maybe version.",
+                           Local<Value> New(Isolate* isolate, double time));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> New(Local<Context> context,
+                                                     double time);
+
+  /**
+   * A specialization of Value::NumberValue that is more efficient
+   * because we know the structure of this object.
+   */
+  double ValueOf() const;
+
+  V8_INLINE static Date* Cast(Value* obj);
+
+  /**
+   * Notification that the embedder has changed the time zone,
+   * daylight savings time, or other date / time configuration
+   * parameters.  V8 keeps a cache of various values used for
+   * date / time computation.  This notification will reset
+   * those cached values for the current context so that date /
+   * time configuration changes would be reflected in the Date
+   * object.
+   *
+   * This API should not be called more than needed as it will
+   * negatively impact the performance of date operations.
+   */
+  static void DateTimeConfigurationChangeNotification(Isolate* isolate);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Number object (ECMA-262, 4.3.21).
+ */
+class V8_EXPORT NumberObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, double value);
+
+  double ValueOf() const;
+
+  V8_INLINE static NumberObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Boolean object (ECMA-262, 4.3.15).
+ */
+class V8_EXPORT BooleanObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, bool value);
+  V8_DEPRECATED("Pass an isolate", static Local<Value> New(bool value));
+
+  bool ValueOf() const;
+
+  V8_INLINE static BooleanObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A String object (ECMA-262, 4.3.18).
+ */
+class V8_EXPORT StringObject : public Object {
+ public:
+  static Local<Value> New(Local<String> value);
+
+  Local<String> ValueOf() const;
+
+  V8_INLINE static StringObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Symbol object (ECMA-262 edition 6).
+ */
+class V8_EXPORT SymbolObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, Local<Symbol> value);
+
+  Local<Symbol> ValueOf() const;
+
+  V8_INLINE static SymbolObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in RegExp constructor (ECMA-262, 15.10).
+ */
+class V8_EXPORT RegExp : public Object {
+ public:
+  /**
+   * Regular expression flag bits. They can be or'ed to enable a set
+   * of flags.
+   */
+  enum Flags {
+    kNone = 0,
+    kGlobal = 1 << 0,
+    kIgnoreCase = 1 << 1,
+    kMultiline = 1 << 2,
+    kSticky = 1 << 3,
+    kUnicode = 1 << 4,
+    kDotAll = 1 << 5,
+  };
+
+  /**
+   * Creates a regular expression from the given pattern string and
+   * the flags bit field. May throw a JavaScript exception as
+   * described in ECMA-262, 15.10.4.1.
+   *
+   * For example,
+   *   RegExp::New(v8::String::New("foo"),
+   *               static_cast<RegExp::Flags>(kGlobal | kMultiline))
+   * is equivalent to evaluating "/foo/gm".
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<RegExp> New(Local<String> pattern,
+                                             Flags flags));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<RegExp> New(Local<Context> context,
+                                                      Local<String> pattern,
+                                                      Flags flags);
+
+  /**
+   * Returns the value of the source property: a string representing
+   * the regular expression.
+   */
+  Local<String> GetSource() const;
+
+  /**
+   * Returns the flags bit field.
+   */
+  Flags GetFlags() const;
+
+  V8_INLINE static RegExp* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A JavaScript value that wraps a C++ void*. This type of value is mainly used
+ * to associate C++ data structures with JavaScript objects.
+ */
+class V8_EXPORT External : public Value {
+ public:
+  static Local<External> New(Isolate* isolate, void* value);
+  V8_INLINE static External* Cast(Value* obj);
+  void* Value() const;
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+#define V8_INTRINSICS_LIST(F)                    \
+  F(ArrayProto_entries, array_entries_iterator)  \
+  F(ArrayProto_forEach, array_for_each_iterator) \
+  F(ArrayProto_keys, array_keys_iterator)        \
+  F(ArrayProto_values, array_values_iterator)    \
+  F(IteratorPrototype, initial_iterator_prototype)
+
+enum Intrinsic {
+#define V8_DECL_INTRINSIC(name, iname) k##name,
+  V8_INTRINSICS_LIST(V8_DECL_INTRINSIC)
+#undef V8_DECL_INTRINSIC
+};
+
+
+// --- Templates ---
+
+
+/**
+ * The superclass of object and function templates.
+ */
+class V8_EXPORT Template : public Data {
+ public:
+  /**
+   * Adds a property to each instance created by this template.
+   *
+   * The property must be defined either as a primitive value, or a template.
+   */
+  void Set(Local<Name> name, Local<Data> value,
+           PropertyAttribute attributes = None);
+  void SetPrivate(Local<Private> name, Local<Data> value,
+                  PropertyAttribute attributes = None);
+  V8_INLINE void Set(Isolate* isolate, const char* name, Local<Data> value);
+
+  void SetAccessorProperty(
+     Local<Name> name,
+     Local<FunctionTemplate> getter = Local<FunctionTemplate>(),
+     Local<FunctionTemplate> setter = Local<FunctionTemplate>(),
+     PropertyAttribute attribute = None,
+     AccessControl settings = DEFAULT);
+
+  /**
+   * Whenever the property with the given name is accessed on objects
+   * created from this Template the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetNativeDataProperty(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+  void SetNativeDataProperty(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+
+  /**
+   * Like SetNativeDataProperty, but V8 will replace the native data property
+   * with a real data property on first access.
+   */
+  void SetLazyDataProperty(Local<Name> name, AccessorNameGetterCallback getter,
+                           Local<Value> data = Local<Value>(),
+                           PropertyAttribute attribute = None);
+
+  /**
+   * During template instantiation, sets the value with the intrinsic property
+   * from the correct context.
+   */
+  void SetIntrinsicDataProperty(Local<Name> name, Intrinsic intrinsic,
+                                PropertyAttribute attribute = None);
+
+ private:
+  Template();
+
+  friend class ObjectTemplate;
+  friend class FunctionTemplate;
+};
+
+
+/**
+ * NamedProperty[Getter|Setter] are used as interceptors on object.
+ * See ObjectTemplate::SetNamedPropertyHandler.
+ */
+typedef void (*NamedPropertyGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns the value if the setter intercepts the request.
+ * Otherwise, returns an empty handle.
+ */
+typedef void (*NamedPropertySetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns a non-empty handle if the interceptor intercepts the request.
+ * The result is an integer encoding property attributes (like v8::None,
+ * v8::DontEnum, etc.)
+ */
+typedef void (*NamedPropertyQueryCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Integer>& info);
+
+
+/**
+ * Returns a non-empty handle if the deleter intercepts the request.
+ * The return value is true if the property could be deleted and false
+ * otherwise.
+ */
+typedef void (*NamedPropertyDeleterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*NamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+
+// TODO(dcarney): Deprecate and remove previous typedefs, and replace
+// GenericNamedPropertyFooCallback with just NamedPropertyFooCallback.
+
+/**
+ * Interceptor for get requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted get request.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict`' mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \code
+ *  void GetterCallback(
+ *    Local<Name> name,
+ *    const v8::PropertyCallbackInfo<v8::Value>& info) {
+ *      info.GetReturnValue().Set(v8_num(42));
+ *  }
+ *
+ *  v8::Local<v8::FunctionTemplate> templ =
+ *      v8::FunctionTemplate::New(isolate);
+ *  templ->InstanceTemplate()->SetHandler(
+ *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+ *  LocalContext env;
+ *  env->Global()
+ *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+ *                                             .ToLocalChecked()
+ *                                             ->NewInstance(env.local())
+ *                                             .ToLocalChecked())
+ *      .FromJust();
+ *  v8::Local<v8::Value> result = CompileRun("obj.a = 17; obj.a");
+ *  CHECK(v8_num(42)->Equals(env.local(), result).FromJust());
+ * \endcode
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyGetterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for set requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the setter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the setter
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param value The value which the property will have if the request
+ * is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertySetterCallback)(
+    Local<Name> property, Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Intercepts all requests that query the attributes of the
+ * property, e.g., getOwnPropertyDescriptor(), propertyIsEnumerable(), and
+ * defineProperty().
+ *
+ * Use `info.GetReturnValue().Set(value)` to set the property attributes. The
+ * value is an interger encoding a `v8::PropertyAttribute`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note Some functions query the property attributes internally, even though
+ * they do not return the attributes. For example, `hasOwnProperty()` can
+ * trigger this interceptor depending on the state of the object.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyQueryCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * Interceptor for delete requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the deleter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)` with a boolean `value`. The `value` is
+ * used as the return value of `delete`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If you need to mimic the behavior of `delete`, i.e., throw in strict
+ * mode instead of returning false, use `info.ShouldThrowOnError()` to determine
+ * if you are in strict mode.
+ *
+ * See also `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyDeleterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*GenericNamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * Interceptor for defineProperty requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the definer successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the definer
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param desc The property descriptor which is used to define the
+ * property if the request is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDefinerCallback)(
+    Local<Name> property, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for getOwnPropertyDescriptor requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted request. The return value must be an object that
+ * can be converted to a PropertyDescriptor, e.g., a `v8::value` returned from
+ * `v8::Object::getOwnPropertyDescriptor`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If GetOwnPropertyDescriptor is intercepted, it will
+ * always return true, i.e., indicate that the property was found.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDescriptorCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyGetterCallback`.
+ */
+typedef void (*IndexedPropertyGetterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertySetterCallback`.
+ */
+typedef void (*IndexedPropertySetterCallback)(
+    uint32_t index,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyQueryCallback`.
+ */
+typedef void (*IndexedPropertyQueryCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDeleterCallback`.
+ */
+typedef void (*IndexedPropertyDeleterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Boolean>& info);
+
+/**
+ * See `v8::GenericNamedPropertyEnumeratorCallback`.
+ */
+typedef void (*IndexedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDefinerCallback`.
+ */
+typedef void (*IndexedPropertyDefinerCallback)(
+    uint32_t index, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDescriptorCallback`.
+ */
+typedef void (*IndexedPropertyDescriptorCallback)(
+    uint32_t index, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Access type specification.
+ */
+enum AccessType {
+  ACCESS_GET,
+  ACCESS_SET,
+  ACCESS_HAS,
+  ACCESS_DELETE,
+  ACCESS_KEYS
+};
+
+
+/**
+ * Returns true if the given context should be allowed to access the given
+ * object.
+ */
+typedef bool (*AccessCheckCallback)(Local<Context> accessing_context,
+                                    Local<Object> accessed_object,
+                                    Local<Value> data);
+
+/**
+ * A FunctionTemplate is used to create functions at runtime. There
+ * can only be one function created from a FunctionTemplate in a
+ * context.  The lifetime of the created function is equal to the
+ * lifetime of the context.  So in case the embedder needs to create
+ * temporary functions that can be collected using Scripts is
+ * preferred.
+ *
+ * Any modification of a FunctionTemplate after first instantiation will trigger
+ * a crash.
+ *
+ * A FunctionTemplate can have properties, these properties are added to the
+ * function object when it is created.
+ *
+ * A FunctionTemplate has a corresponding instance template which is
+ * used to create object instances when the function is used as a
+ * constructor. Properties added to the instance template are added to
+ * each object instance.
+ *
+ * A FunctionTemplate can have a prototype template. The prototype template
+ * is used to create the prototype object of the function.
+ *
+ * The following example shows how to use a FunctionTemplate:
+ *
+ * \code
+ *    v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(isolate);
+ *    t->Set(isolate, "func_property", v8::Number::New(isolate, 1));
+ *
+ *    v8::Local<v8::Template> proto_t = t->PrototypeTemplate();
+ *    proto_t->Set(isolate,
+ *                 "proto_method",
+ *                 v8::FunctionTemplate::New(isolate, InvokeCallback));
+ *    proto_t->Set(isolate, "proto_const", v8::Number::New(isolate, 2));
+ *
+ *    v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
+ *    instance_t->SetAccessor(String::NewFromUtf8(isolate, "instance_accessor"),
+ *                            InstanceAccessorCallback);
+ *    instance_t->SetNamedPropertyHandler(PropertyHandlerCallback);
+ *    instance_t->Set(String::NewFromUtf8(isolate, "instance_property"),
+ *                    Number::New(isolate, 3));
+ *
+ *    v8::Local<v8::Function> function = t->GetFunction();
+ *    v8::Local<v8::Object> instance = function->NewInstance();
+ * \endcode
+ *
+ * Let's use "function" as the JS variable name of the function object
+ * and "instance" for the instance object created above.  The function
+ * and the instance will have the following properties:
+ *
+ * \code
+ *   func_property in function == true;
+ *   function.func_property == 1;
+ *
+ *   function.prototype.proto_method() invokes 'InvokeCallback'
+ *   function.prototype.proto_const == 2;
+ *
+ *   instance instanceof function == true;
+ *   instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   instance.instance_property == 3;
+ * \endcode
+ *
+ * A FunctionTemplate can inherit from another one by calling the
+ * FunctionTemplate::Inherit method.  The following graph illustrates
+ * the semantics of inheritance:
+ *
+ * \code
+ *   FunctionTemplate Parent  -> Parent() . prototype -> { }
+ *     ^                                                  ^
+ *     | Inherit(Parent)                                  | .__proto__
+ *     |                                                  |
+ *   FunctionTemplate Child   -> Child()  . prototype -> { }
+ * \endcode
+ *
+ * A FunctionTemplate 'Child' inherits from 'Parent', the prototype
+ * object of the Child() function has __proto__ pointing to the
+ * Parent() function's prototype object. An instance of the Child
+ * function has all properties on Parent's instance templates.
+ *
+ * Let Parent be the FunctionTemplate initialized in the previous
+ * section and create a Child FunctionTemplate by:
+ *
+ * \code
+ *   Local<FunctionTemplate> parent = t;
+ *   Local<FunctionTemplate> child = FunctionTemplate::New();
+ *   child->Inherit(parent);
+ *
+ *   Local<Function> child_function = child->GetFunction();
+ *   Local<Object> child_instance = child_function->NewInstance();
+ * \endcode
+ *
+ * The Child function and Child instance will have the following
+ * properties:
+ *
+ * \code
+ *   child_func.prototype.__proto__ == function.prototype;
+ *   child_instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   child_instance.instance_property == 3;
+ * \endcode
+ */
+class V8_EXPORT FunctionTemplate : public Template {
+ public:
+  /** Creates a function template.*/
+  static Local<FunctionTemplate> New(
+      Isolate* isolate, FunctionCallback callback = 0,
+      Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<FunctionTemplate> FromSnapshot(Isolate* isolate,
+                                                   size_t index);
+
+  /**
+   * Creates a function template backed/cached by a private property.
+   */
+  static Local<FunctionTemplate> NewWithCache(
+      Isolate* isolate, FunctionCallback callback,
+      Local<Private> cache_property, Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0);
+
+  /** Returns the unique function instance in the current execution context.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Function> GetFunction());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Function> GetFunction(
+      Local<Context> context);
+
+  /**
+   * Similar to Context::NewRemoteContext, this creates an instance that
+   * isn't backed by an actual object.
+   *
+   * The InstanceTemplate of this FunctionTemplate must have access checks with
+   * handlers installed.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewRemoteInstance();
+
+  /**
+   * Set the call-handler callback for a FunctionTemplate.  This
+   * callback is called whenever the function created from this
+   * FunctionTemplate is called.
+   */
+  void SetCallHandler(FunctionCallback callback,
+                      Local<Value> data = Local<Value>());
+
+  /** Set the predefined length property for the FunctionTemplate. */
+  void SetLength(int length);
+
+  /** Get the InstanceTemplate. */
+  Local<ObjectTemplate> InstanceTemplate();
+
+  /**
+   * Causes the function template to inherit from a parent function template.
+   * This means the the function's prototype.__proto__ is set to the parent
+   * function's prototype.
+   **/
+  void Inherit(Local<FunctionTemplate> parent);
+
+  /**
+   * A PrototypeTemplate is the template used to create the prototype object
+   * of the function created by this template.
+   */
+  Local<ObjectTemplate> PrototypeTemplate();
+
+  /**
+   * A PrototypeProviderTemplate is another function template whose prototype
+   * property is used for this template. This is mutually exclusive with setting
+   * a prototype template indirectly by calling PrototypeTemplate() or using
+   * Inherit().
+   **/
+  void SetPrototypeProviderTemplate(Local<FunctionTemplate> prototype_provider);
+
+  /**
+   * Set the class name of the FunctionTemplate.  This is used for
+   * printing objects created with the function created from the
+   * FunctionTemplate as its constructor.
+   */
+  void SetClassName(Local<String> name);
+
+
+  /**
+   * When set to true, no access check will be performed on the receiver of a
+   * function call.  Currently defaults to true, but this is subject to change.
+   */
+  void SetAcceptAnyReceiver(bool value);
+
+  /**
+   * Determines whether the __proto__ accessor ignores instances of
+   * the function template.  If instances of the function template are
+   * ignored, __proto__ skips all instances and instead returns the
+   * next object in the prototype chain.
+   *
+   * Call with a value of true to make the __proto__ accessor ignore
+   * instances of the function template.  Call with a value of false
+   * to make the __proto__ accessor not ignore instances of the
+   * function template.  By default, instances of a function template
+   * are not ignored.
+   */
+  void SetHiddenPrototype(bool value);
+
+  /**
+   * Sets the ReadOnly flag in the attributes of the 'prototype' property
+   * of functions created from this FunctionTemplate to true.
+   */
+  void ReadOnlyPrototype();
+
+  /**
+   * Removes the prototype property from functions created from this
+   * FunctionTemplate.
+   */
+  void RemovePrototype();
+
+  /**
+   * Returns true if the given object is an instance of this function
+   * template.
+   */
+  bool HasInstance(Local<Value> object);
+
+ private:
+  FunctionTemplate();
+  friend class Context;
+  friend class ObjectTemplate;
+};
+
+/**
+ * Configuration flags for v8::NamedPropertyHandlerConfiguration or
+ * v8::IndexedPropertyHandlerConfiguration.
+ */
+enum class PropertyHandlerFlags {
+  /**
+   * None.
+   */
+  kNone = 0,
+
+  /**
+   * See ALL_CAN_READ above.
+   */
+  kAllCanRead = 1,
+
+  /** Will not call into interceptor for properties on the receiver or prototype
+   * chain, i.e., only call into interceptor for properties that do not exist.
+   * Currently only valid for named interceptors.
+   */
+  kNonMasking = 1 << 1,
+
+  /**
+   * Will not call into interceptor for symbol lookup.  Only meaningful for
+   * named interceptors.
+   */
+  kOnlyInterceptStrings = 1 << 2,
+};
+
+struct NamedPropertyHandlerConfiguration {
+  NamedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      GenericNamedPropertyGetterCallback getter = 0,
+      GenericNamedPropertySetterCallback setter = 0,
+      GenericNamedPropertyQueryCallback query = 0,
+      GenericNamedPropertyDeleterCallback deleter = 0,
+      GenericNamedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  NamedPropertyHandlerConfiguration(
+      GenericNamedPropertyGetterCallback getter,
+      GenericNamedPropertySetterCallback setter,
+      GenericNamedPropertyDescriptorCallback descriptor,
+      GenericNamedPropertyDeleterCallback deleter,
+      GenericNamedPropertyEnumeratorCallback enumerator,
+      GenericNamedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  GenericNamedPropertyGetterCallback getter;
+  GenericNamedPropertySetterCallback setter;
+  GenericNamedPropertyQueryCallback query;
+  GenericNamedPropertyDeleterCallback deleter;
+  GenericNamedPropertyEnumeratorCallback enumerator;
+  GenericNamedPropertyDefinerCallback definer;
+  GenericNamedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+struct IndexedPropertyHandlerConfiguration {
+  IndexedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      IndexedPropertyGetterCallback getter = 0,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyHandlerConfiguration(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter,
+      IndexedPropertyDescriptorCallback descriptor,
+      IndexedPropertyDeleterCallback deleter,
+      IndexedPropertyEnumeratorCallback enumerator,
+      IndexedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyGetterCallback getter;
+  IndexedPropertySetterCallback setter;
+  IndexedPropertyQueryCallback query;
+  IndexedPropertyDeleterCallback deleter;
+  IndexedPropertyEnumeratorCallback enumerator;
+  IndexedPropertyDefinerCallback definer;
+  IndexedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+/**
+ * An ObjectTemplate is used to create objects at runtime.
+ *
+ * Properties added to an ObjectTemplate are added to each object
+ * created from the ObjectTemplate.
+ */
+class V8_EXPORT ObjectTemplate : public Template {
+ public:
+  /** Creates an ObjectTemplate. */
+  static Local<ObjectTemplate> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> constructor = Local<FunctionTemplate>());
+  static V8_DEPRECATED("Use isolate version", Local<ObjectTemplate> New());
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<ObjectTemplate> FromSnapshot(Isolate* isolate,
+                                                 size_t index);
+
+  /** Creates a new instance of this template.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Object> NewInstance());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(Local<Context> context);
+
+  /**
+   * Sets an accessor on the object template.
+   *
+   * Whenever the property with the given name is accessed on objects
+   * created from this ObjectTemplate the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetAccessor(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+  void SetAccessor(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string is accessed on objects created
+   * from this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * SetNamedPropertyHandler() is different from SetHandler(), in
+   * that the latter can intercept symbol-named properties as well as
+   * string-named properties when called with a
+   * NamedPropertyHandlerConfiguration. New code should use SetHandler().
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if a property is present,
+   *   and if present, get its attributes.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the named
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetNamedPropertyHandler(NamedPropertyGetterCallback getter,
+                               NamedPropertySetterCallback setter = 0,
+                               NamedPropertyQueryCallback query = 0,
+                               NamedPropertyDeleterCallback deleter = 0,
+                               NamedPropertyEnumeratorCallback enumerator = 0,
+                               Local<Value> data = Local<Value>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string or a symbol is accessed on
+   * objects created from this object template, the provided callback is
+   * invoked instead of accessing the property directly on the JavaScript
+   * object.
+   *
+   * @param configuration The NamedPropertyHandlerConfiguration that defines the
+   * callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const NamedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if an object has a property.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the indexed
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetIndexedPropertyHandler(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>()) {
+    SetHandler(IndexedPropertyHandlerConfiguration(getter, setter, query,
+                                                   deleter, enumerator, data));
+  }
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * @param configuration The IndexedPropertyHandlerConfiguration that defines
+   * the callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const IndexedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets the callback to be used when calling instances created from
+   * this template as a function.  If no callback is set, instances
+   * behave like normal JavaScript objects that cannot be called as a
+   * function.
+   */
+  void SetCallAsFunctionHandler(FunctionCallback callback,
+                                Local<Value> data = Local<Value>());
+
+  /**
+   * Mark object instances of the template as undetectable.
+   *
+   * In many ways, undetectable objects behave as though they are not
+   * there.  They behave like 'undefined' in conditionals and when
+   * printed.  However, properties can be accessed and called as on
+   * normal objects.
+   */
+  void MarkAsUndetectable();
+
+  /**
+   * Sets access check callback on the object template and enables access
+   * checks.
+   *
+   * When accessing properties on instances of this object template,
+   * the access check callback will be called to determine whether or
+   * not to allow cross-context access to the properties.
+   */
+  void SetAccessCheckCallback(AccessCheckCallback callback,
+                              Local<Value> data = Local<Value>());
+
+  /**
+   * Like SetAccessCheckCallback but invokes an interceptor on failed access
+   * checks instead of looking up all-can-read properties. You can only use
+   * either this method or SetAccessCheckCallback, but not both at the same
+   * time.
+   */
+  void SetAccessCheckCallbackAndHandler(
+      AccessCheckCallback callback,
+      const NamedPropertyHandlerConfiguration& named_handler,
+      const IndexedPropertyHandlerConfiguration& indexed_handler,
+      Local<Value> data = Local<Value>());
+
+  /**
+   * Gets the number of internal fields for objects generated from
+   * this template.
+   */
+  int InternalFieldCount();
+
+  /**
+   * Sets the number of internal fields for objects generated from
+   * this template.
+   */
+  void SetInternalFieldCount(int value);
+
+  /**
+   * Returns true if the object will be an immutable prototype exotic object.
+   */
+  bool IsImmutableProto();
+
+  /**
+   * Makes the ObjectTempate for an immutable prototype exotic object, with an
+   * immutable __proto__.
+   */
+  void SetImmutableProto();
+
+ private:
+  ObjectTemplate();
+  static Local<ObjectTemplate> New(internal::Isolate* isolate,
+                                   Local<FunctionTemplate> constructor);
+  friend class FunctionTemplate;
+};
+
+/**
+ * A Signature specifies which receiver is valid for a function.
+ *
+ * A receiver matches a given signature if the receiver (or any of its
+ * hidden prototypes) was created from the signature's FunctionTemplate, or
+ * from a FunctionTemplate that inherits directly or indirectly from the
+ * signature's FunctionTemplate.
+ */
+class V8_EXPORT Signature : public Data {
+ public:
+  static Local<Signature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  Signature();
+};
+
+
+/**
+ * An AccessorSignature specifies which receivers are valid parameters
+ * to an accessor callback.
+ */
+class V8_EXPORT AccessorSignature : public Data {
+ public:
+  static Local<AccessorSignature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  AccessorSignature();
+};
+
+
+// --- Extensions ---
+
+class V8_EXPORT ExternalOneByteStringResourceImpl
+    : public String::ExternalOneByteStringResource {
+ public:
+  ExternalOneByteStringResourceImpl() : data_(0), length_(0) {}
+  ExternalOneByteStringResourceImpl(const char* data, size_t length)
+      : data_(data), length_(length) {}
+  const char* data() const { return data_; }
+  size_t length() const { return length_; }
+
+ private:
+  const char* data_;
+  size_t length_;
+};
+
+/**
+ * Ignore
+ */
+class V8_EXPORT Extension {  // NOLINT
+ public:
+  // Note that the strings passed into this constructor must live as long
+  // as the Extension itself.
+  Extension(const char* name,
+            const char* source = 0,
+            int dep_count = 0,
+            const char** deps = 0,
+            int source_length = -1);
+  virtual ~Extension() { }
+  virtual Local<FunctionTemplate> GetNativeFunctionTemplate(
+      Isolate* isolate, Local<String> name) {
+    return Local<FunctionTemplate>();
+  }
+
+  const char* name() const { return name_; }
+  size_t source_length() const { return source_length_; }
+  const String::ExternalOneByteStringResource* source() const {
+    return &source_; }
+  int dependency_count() { return dep_count_; }
+  const char** dependencies() { return deps_; }
+  void set_auto_enable(bool value) { auto_enable_ = value; }
+  bool auto_enable() { return auto_enable_; }
+
+  // Disallow copying and assigning.
+  Extension(const Extension&) = delete;
+  void operator=(const Extension&) = delete;
+
+ private:
+  const char* name_;
+  size_t source_length_;  // expected to initialize before source_
+  ExternalOneByteStringResourceImpl source_;
+  int dep_count_;
+  const char** deps_;
+  bool auto_enable_;
+};
+
+
+void V8_EXPORT RegisterExtension(Extension* extension);
+
+
+// --- Statics ---
+
+V8_INLINE Local<Primitive> Undefined(Isolate* isolate);
+V8_INLINE Local<Primitive> Null(Isolate* isolate);
+V8_INLINE Local<Boolean> True(Isolate* isolate);
+V8_INLINE Local<Boolean> False(Isolate* isolate);
+
+/**
+ * A set of constraints that specifies the limits of the runtime's memory use.
+ * You must set the heap size before initializing the VM - the size cannot be
+ * adjusted after the VM is initialized.
+ *
+ * If you are using threads then you should hold the V8::Locker lock while
+ * setting the stack limit and you must set a non-default stack limit separately
+ * for each thread.
+ *
+ * The arguments for set_max_semi_space_size, set_max_old_space_size,
+ * set_max_executable_size, set_code_range_size specify limits in MB.
+ */
+class V8_EXPORT ResourceConstraints {
+ public:
+  ResourceConstraints();
+
+  /**
+   * Configures the constraints with reasonable default values based on the
+   * capabilities of the current device the VM is running on.
+   *
+   * \param physical_memory The total amount of physical memory on the current
+   *   device, in bytes.
+   * \param virtual_memory_limit The amount of virtual memory on the current
+   *   device, in bytes, or zero, if there is no limit.
+   */
+  void ConfigureDefaults(uint64_t physical_memory,
+                         uint64_t virtual_memory_limit);
+
+  int max_semi_space_size() const { return max_semi_space_size_; }
+  void set_max_semi_space_size(int limit_in_mb) {
+    max_semi_space_size_ = limit_in_mb;
+  }
+  int max_old_space_size() const { return max_old_space_size_; }
+  void set_max_old_space_size(int limit_in_mb) {
+    max_old_space_size_ = limit_in_mb;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    int max_executable_size() const) {
+    return max_executable_size_;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    void set_max_executable_size(int limit_in_mb)) {
+    max_executable_size_ = limit_in_mb;
+  }
+  uint32_t* stack_limit() const { return stack_limit_; }
+  // Sets an address beyond which the VM's stack may not grow.
+  void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
+  size_t code_range_size() const { return code_range_size_; }
+  void set_code_range_size(size_t limit_in_mb) {
+    code_range_size_ = limit_in_mb;
+  }
+  size_t max_zone_pool_size() const { return max_zone_pool_size_; }
+  void set_max_zone_pool_size(const size_t bytes) {
+    max_zone_pool_size_ = bytes;
+  }
+
+ private:
+  int max_semi_space_size_;
+  int max_old_space_size_;
+  int max_executable_size_;
+  uint32_t* stack_limit_;
+  size_t code_range_size_;
+  size_t max_zone_pool_size_;
+};
+
+
+// --- Exceptions ---
+
+
+typedef void (*FatalErrorCallback)(const char* location, const char* message);
+
+typedef void (*OOMErrorCallback)(const char* location, bool is_heap_oom);
+
+typedef void (*MessageCallback)(Local<Message> message, Local<Value> data);
+
+// --- Tracing ---
+
+typedef void (*LogEventCallback)(const char* name, int event);
+
+/**
+ * Create new error objects by calling the corresponding error object
+ * constructor with the message.
+ */
+class V8_EXPORT Exception {
+ public:
+  static Local<Value> RangeError(Local<String> message);
+  static Local<Value> ReferenceError(Local<String> message);
+  static Local<Value> SyntaxError(Local<String> message);
+  static Local<Value> TypeError(Local<String> message);
+  static Local<Value> Error(Local<String> message);
+
+  /**
+   * Creates an error message for the given exception.
+   * Will try to reconstruct the original stack trace from the exception value,
+   * or capture the current stack trace if not available.
+   */
+  static Local<Message> CreateMessage(Isolate* isolate, Local<Value> exception);
+  V8_DEPRECATED("Use version with an Isolate*",
+                static Local<Message> CreateMessage(Local<Value> exception));
+
+  /**
+   * Returns the original stack trace that was captured at the creation time
+   * of a given exception, or an empty handle if not available.
+   */
+  static Local<StackTrace> GetStackTrace(Local<Value> exception);
+};
+
+
+// --- Counters Callbacks ---
+
+typedef int* (*CounterLookupCallback)(const char* name);
+
+typedef void* (*CreateHistogramCallback)(const char* name,
+                                         int min,
+                                         int max,
+                                         size_t buckets);
+
+typedef void (*AddHistogramSampleCallback)(void* histogram, int sample);
+
+// --- Memory Allocation Callback ---
+enum ObjectSpace {
+  kObjectSpaceNewSpace = 1 << 0,
+  kObjectSpaceOldSpace = 1 << 1,
+  kObjectSpaceCodeSpace = 1 << 2,
+  kObjectSpaceMapSpace = 1 << 3,
+  kObjectSpaceLoSpace = 1 << 4,
+  kObjectSpaceAll = kObjectSpaceNewSpace | kObjectSpaceOldSpace |
+                    kObjectSpaceCodeSpace | kObjectSpaceMapSpace |
+                    kObjectSpaceLoSpace
+};
+
+  enum AllocationAction {
+    kAllocationActionAllocate = 1 << 0,
+    kAllocationActionFree = 1 << 1,
+    kAllocationActionAll = kAllocationActionAllocate | kAllocationActionFree
+  };
+
+// --- Enter/Leave Script Callback ---
+typedef void (*BeforeCallEnteredCallback)(Isolate*);
+typedef void (*CallCompletedCallback)(Isolate*);
+typedef void (*DeprecatedCallCompletedCallback)();
+
+/**
+ * HostImportDynamicallyCallback is called when we require the
+ * embedder to load a module. This is used as part of the dynamic
+ * import syntax. The behavior of this callback is not specified in
+ * EcmaScript.
+ *
+ * The referrer is the name of the file which calls the dynamic
+ * import. The referrer can be used to resolve the module location.
+ *
+ * The specifier is the name of the module that should be imported.
+ *
+ * The DynamicImportResult object is used to signal success or failure
+ * by calling it's respective methods.
+ *
+ */
+typedef void (*HostImportModuleDynamicallyCallback)(
+    Isolate* isolate, Local<String> referrer, Local<String> specifier,
+    Local<DynamicImportResult> result);
+
+/**
+ * PromiseHook with type kInit is called when a new promise is
+ * created. When a new promise is created as part of the chain in the
+ * case of Promise.then or in the intermediate promises created by
+ * Promise.{race, all}/AsyncFunctionAwait, we pass the parent promise
+ * otherwise we pass undefined.
+ *
+ * PromiseHook with type kResolve is called at the beginning of
+ * resolve or reject function defined by CreateResolvingFunctions.
+ *
+ * PromiseHook with type kBefore is called at the beginning of the
+ * PromiseReactionJob.
+ *
+ * PromiseHook with type kAfter is called right at the end of the
+ * PromiseReactionJob.
+ */
+enum class PromiseHookType { kInit, kResolve, kBefore, kAfter };
+
+typedef void (*PromiseHook)(PromiseHookType type, Local<Promise> promise,
+                            Local<Value> parent);
+
+// --- Promise Reject Callback ---
+enum PromiseRejectEvent {
+  kPromiseRejectWithNoHandler = 0,
+  kPromiseHandlerAddedAfterReject = 1
+};
+
+class PromiseRejectMessage {
+ public:
+  PromiseRejectMessage(Local<Promise> promise, PromiseRejectEvent event,
+                       Local<Value> value, Local<StackTrace> stack_trace)
+      : promise_(promise),
+        event_(event),
+        value_(value),
+        stack_trace_(stack_trace) {}
+
+  V8_INLINE Local<Promise> GetPromise() const { return promise_; }
+  V8_INLINE PromiseRejectEvent GetEvent() const { return event_; }
+  V8_INLINE Local<Value> GetValue() const { return value_; }
+
+  V8_DEPRECATED("Use v8::Exception::CreateMessage(GetValue())->GetStackTrace()",
+                V8_INLINE Local<StackTrace> GetStackTrace() const) {
+    return stack_trace_;
+  }
+
+ private:
+  Local<Promise> promise_;
+  PromiseRejectEvent event_;
+  Local<Value> value_;
+  Local<StackTrace> stack_trace_;
+};
+
+typedef void (*PromiseRejectCallback)(PromiseRejectMessage message);
+
+// --- Microtasks Callbacks ---
+typedef void (*MicrotasksCompletedCallback)(Isolate*);
+typedef void (*MicrotaskCallback)(void* data);
+
+
+/**
+ * Policy for running microtasks:
+ *   - explicit: microtasks are invoked with Isolate::RunMicrotasks() method;
+ *   - scoped: microtasks invocation is controlled by MicrotasksScope objects;
+ *   - auto: microtasks are invoked when the script call depth decrements
+ *           to zero.
+ */
+enum class MicrotasksPolicy { kExplicit, kScoped, kAuto };
+
+
+/**
+ * This scope is used to control microtasks when kScopeMicrotasksInvocation
+ * is used on Isolate. In this mode every non-primitive call to V8 should be
+ * done inside some MicrotasksScope.
+ * Microtasks are executed when topmost MicrotasksScope marked as kRunMicrotasks
+ * exits.
+ * kDoNotRunMicrotasks should be used to annotate calls not intended to trigger
+ * microtasks.
+ */
+class V8_EXPORT MicrotasksScope {
+ public:
+  enum Type { kRunMicrotasks, kDoNotRunMicrotasks };
+
+  MicrotasksScope(Isolate* isolate, Type type);
+  ~MicrotasksScope();
+
+  /**
+   * Runs microtasks if no kRunMicrotasks scope is currently active.
+   */
+  static void PerformCheckpoint(Isolate* isolate);
+
+  /**
+   * Returns current depth of nested kRunMicrotasks scopes.
+   */
+  static int GetCurrentDepth(Isolate* isolate);
+
+  /**
+   * Returns true while microtasks are being executed.
+   */
+  static bool IsRunningMicrotasks(Isolate* isolate);
+
+  // Prevent copying.
+  MicrotasksScope(const MicrotasksScope&) = delete;
+  MicrotasksScope& operator=(const MicrotasksScope&) = delete;
+
+ private:
+  internal::Isolate* const isolate_;
+  bool run_;
+};
+
+
+// --- Failed Access Check Callback ---
+typedef void (*FailedAccessCheckCallback)(Local<Object> target,
+                                          AccessType type,
+                                          Local<Value> data);
+
+// --- AllowCodeGenerationFromStrings callbacks ---
+
+/**
+ * Callback to check if code generation from strings is allowed. See
+ * Context::AllowCodeGenerationFromStrings.
+ */
+typedef bool (*AllowCodeGenerationFromStringsCallback)(Local<Context> context);
+
+// --- WASM compilation callbacks ---
+typedef bool (*ExtensionCallback)(const FunctionCallbackInfo<Value>&);
+
+// --- Garbage Collection Callbacks ---
+
+/**
+ * Applications can register callback functions which will be called before and
+ * after certain garbage collection operations.  Allocations are not allowed in
+ * the callback functions, you therefore cannot manipulate objects (set or
+ * delete properties for example) since it is possible such operations will
+ * result in the allocation of objects.
+ */
+enum GCType {
+  kGCTypeScavenge = 1 << 0,
+  kGCTypeMarkSweepCompact = 1 << 1,
+  kGCTypeIncrementalMarking = 1 << 2,
+  kGCTypeProcessWeakCallbacks = 1 << 3,
+  kGCTypeAll = kGCTypeScavenge | kGCTypeMarkSweepCompact |
+               kGCTypeIncrementalMarking | kGCTypeProcessWeakCallbacks
+};
+
+/**
+ * GCCallbackFlags is used to notify additional information about the GC
+ * callback.
+ *   - kGCCallbackFlagConstructRetainedObjectInfos: The GC callback is for
+ *     constructing retained object infos.
+ *   - kGCCallbackFlagForced: The GC callback is for a forced GC for testing.
+ *   - kGCCallbackFlagSynchronousPhantomCallbackProcessing: The GC callback
+ *     is called synchronously without getting posted to an idle task.
+ *   - kGCCallbackFlagCollectAllAvailableGarbage: The GC callback is called
+ *     in a phase where V8 is trying to collect all available garbage
+ *     (e.g., handling a low memory notification).
+ *   - kGCCallbackScheduleIdleGarbageCollection: The GC callback is called to
+ *     trigger an idle garbage collection.
+ */
+enum GCCallbackFlags {
+  kNoGCCallbackFlags = 0,
+  kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1,
+  kGCCallbackFlagForced = 1 << 2,
+  kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3,
+  kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4,
+  kGCCallbackFlagCollectAllExternalMemory = 1 << 5,
+  kGCCallbackScheduleIdleGarbageCollection = 1 << 6,
+};
+
+typedef void (*GCCallback)(GCType type, GCCallbackFlags flags);
+
+typedef void (*InterruptCallback)(Isolate* isolate, void* data);
+
+
+/**
+ * Collection of V8 heap information.
+ *
+ * Instances of this class can be passed to v8::V8::HeapStatistics to
+ * get heap statistics from V8.
+ */
+class V8_EXPORT HeapStatistics {
+ public:
+  HeapStatistics();
+  size_t total_heap_size() { return total_heap_size_; }
+  size_t total_heap_size_executable() { return total_heap_size_executable_; }
+  size_t total_physical_size() { return total_physical_size_; }
+  size_t total_available_size() { return total_available_size_; }
+  size_t used_heap_size() { return used_heap_size_; }
+  size_t heap_size_limit() { return heap_size_limit_; }
+  size_t malloced_memory() { return malloced_memory_; }
+  size_t peak_malloced_memory() { return peak_malloced_memory_; }
+
+  /**
+   * Returns a 0/1 boolean, which signifies whether the V8 overwrite heap
+   * garbage with a bit pattern.
+   */
+  size_t does_zap_garbage() { return does_zap_garbage_; }
+
+ private:
+  size_t total_heap_size_;
+  size_t total_heap_size_executable_;
+  size_t total_physical_size_;
+  size_t total_available_size_;
+  size_t used_heap_size_;
+  size_t heap_size_limit_;
+  size_t malloced_memory_;
+  size_t peak_malloced_memory_;
+  bool does_zap_garbage_;
+
+  friend class V8;
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapSpaceStatistics {
+ public:
+  HeapSpaceStatistics();
+  const char* space_name() { return space_name_; }
+  size_t space_size() { return space_size_; }
+  size_t space_used_size() { return space_used_size_; }
+  size_t space_available_size() { return space_available_size_; }
+  size_t physical_space_size() { return physical_space_size_; }
+
+ private:
+  const char* space_name_;
+  size_t space_size_;
+  size_t space_used_size_;
+  size_t space_available_size_;
+  size_t physical_space_size_;
+
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapObjectStatistics {
+ public:
+  HeapObjectStatistics();
+  const char* object_type() { return object_type_; }
+  const char* object_sub_type() { return object_sub_type_; }
+  size_t object_count() { return object_count_; }
+  size_t object_size() { return object_size_; }
+
+ private:
+  const char* object_type_;
+  const char* object_sub_type_;
+  size_t object_count_;
+  size_t object_size_;
+
+  friend class Isolate;
+};
+
+class V8_EXPORT HeapCodeStatistics {
+ public:
+  HeapCodeStatistics();
+  size_t code_and_metadata_size() { return code_and_metadata_size_; }
+  size_t bytecode_and_metadata_size() { return bytecode_and_metadata_size_; }
+
+ private:
+  size_t code_and_metadata_size_;
+  size_t bytecode_and_metadata_size_;
+
+  friend class Isolate;
+};
+
+class RetainedObjectInfo;
+
+
+/**
+ * FunctionEntryHook is the type of the profile entry hook called at entry to
+ * any generated function when function-level profiling is enabled.
+ *
+ * \param function the address of the function that's being entered.
+ * \param return_addr_location points to a location on stack where the machine
+ *    return address resides. This can be used to identify the caller of
+ *    \p function, and/or modified to divert execution when \p function exits.
+ *
+ * \note the entry hook must not cause garbage collection.
+ */
+typedef void (*FunctionEntryHook)(uintptr_t function,
+                                  uintptr_t return_addr_location);
+
+/**
+ * A JIT code event is issued each time code is added, moved or removed.
+ *
+ * \note removal events are not currently issued.
+ */
+struct JitCodeEvent {
+  enum EventType {
+    CODE_ADDED,
+    CODE_MOVED,
+    CODE_REMOVED,
+    CODE_ADD_LINE_POS_INFO,
+    CODE_START_LINE_INFO_RECORDING,
+    CODE_END_LINE_INFO_RECORDING
+  };
+  // Definition of the code position type. The "POSITION" type means the place
+  // in the source code which are of interest when making stack traces to
+  // pin-point the source location of a stack frame as close as possible.
+  // The "STATEMENT_POSITION" means the place at the beginning of each
+  // statement, and is used to indicate possible break locations.
+  enum PositionType { POSITION, STATEMENT_POSITION };
+
+  // Type of event.
+  EventType type;
+  // Start of the instructions.
+  void* code_start;
+  // Size of the instructions.
+  size_t code_len;
+  // Script info for CODE_ADDED event.
+  Local<UnboundScript> script;
+  // User-defined data for *_LINE_INFO_* event. It's used to hold the source
+  // code line information which is returned from the
+  // CODE_START_LINE_INFO_RECORDING event. And it's passed to subsequent
+  // CODE_ADD_LINE_POS_INFO and CODE_END_LINE_INFO_RECORDING events.
+  void* user_data;
+
+  struct name_t {
+    // Name of the object associated with the code, note that the string is not
+    // zero-terminated.
+    const char* str;
+    // Number of chars in str.
+    size_t len;
+  };
+
+  struct line_info_t {
+    // PC offset
+    size_t offset;
+    // Code postion
+    size_t pos;
+    // The position type.
+    PositionType position_type;
+  };
+
+  union {
+    // Only valid for CODE_ADDED.
+    struct name_t name;
+
+    // Only valid for CODE_ADD_LINE_POS_INFO
+    struct line_info_t line_info;
+
+    // New location of instructions. Only valid for CODE_MOVED.
+    void* new_code_start;
+  };
+};
+
+/**
+ * Option flags passed to the SetRAILMode function.
+ * See documentation https://developers.google.com/web/tools/chrome-devtools/
+ * profile/evaluate-performance/rail
+ */
+enum RAILMode {
+  // Response performance mode: In this mode very low virtual machine latency
+  // is provided. V8 will try to avoid JavaScript execution interruptions.
+  // Throughput may be throttled.
+  PERFORMANCE_RESPONSE,
+  // Animation performance mode: In this mode low virtual machine latency is
+  // provided. V8 will try to avoid as many JavaScript execution interruptions
+  // as possible. Throughput may be throttled. This is the default mode.
+  PERFORMANCE_ANIMATION,
+  // Idle performance mode: The embedder is idle. V8 can complete deferred work
+  // in this mode.
+  PERFORMANCE_IDLE,
+  // Load performance mode: In this mode high throughput is provided. V8 may
+  // turn off latency optimizations.
+  PERFORMANCE_LOAD
+};
+
+/**
+ * Option flags passed to the SetJitCodeEventHandler function.
+ */
+enum JitCodeEventOptions {
+  kJitCodeEventDefault = 0,
+  // Generate callbacks for already existent code.
+  kJitCodeEventEnumExisting = 1
+};
+
+
+/**
+ * Callback function passed to SetJitCodeEventHandler.
+ *
+ * \param event code add, move or removal event.
+ */
+typedef void (*JitCodeEventHandler)(const JitCodeEvent* event);
+
+
+/**
+ * Interface for iterating through all external resources in the heap.
+ */
+class V8_EXPORT ExternalResourceVisitor {  // NOLINT
+ public:
+  virtual ~ExternalResourceVisitor() {}
+  virtual void VisitExternalString(Local<String> string) {}
+};
+
+
+/**
+ * Interface for iterating through all the persistent handles in the heap.
+ */
+class V8_EXPORT PersistentHandleVisitor {  // NOLINT
+ public:
+  virtual ~PersistentHandleVisitor() {}
+  virtual void VisitPersistentHandle(Persistent<Value>* value,
+                                     uint16_t class_id) {}
+};
+
+/**
+ * Memory pressure level for the MemoryPressureNotification.
+ * kNone hints V8 that there is no memory pressure.
+ * kModerate hints V8 to speed up incremental garbage collection at the cost of
+ * of higher latency due to garbage collection pauses.
+ * kCritical hints V8 to free memory as soon as possible. Garbage collection
+ * pauses at this level will be large.
+ */
+enum class MemoryPressureLevel { kNone, kModerate, kCritical };
+
+/**
+ * Interface for tracing through the embedder heap. During a v8 garbage
+ * collection, v8 collects hidden fields of all potential wrappers, and at the
+ * end of its marking phase iterates the collection and asks the embedder to
+ * trace through its heap and use reporter to report each JavaScript object
+ * reachable from any of the given wrappers.
+ *
+ * Before the first call to the TraceWrappersFrom function TracePrologue will be
+ * called. When the garbage collection cycle is finished, TraceEpilogue will be
+ * called.
+ */
+class V8_EXPORT EmbedderHeapTracer {
+ public:
+  enum ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION };
+
+  struct AdvanceTracingActions {
+    explicit AdvanceTracingActions(ForceCompletionAction force_completion_)
+        : force_completion(force_completion_) {}
+
+    ForceCompletionAction force_completion;
+  };
+
+  /**
+   * Called by v8 to register internal fields of found wrappers.
+   *
+   * The embedder is expected to store them somewhere and trace reachable
+   * wrappers from them when called through |AdvanceTracing|.
+   */
+  virtual void RegisterV8References(
+      const std::vector<std::pair<void*, void*> >& embedder_fields) = 0;
+
+  /**
+   * Called at the beginning of a GC cycle.
+   */
+  virtual void TracePrologue() = 0;
+
+  /**
+   * Called to to make a tracing step in the embedder.
+   *
+   * The embedder is expected to trace its heap starting from wrappers reported
+   * by RegisterV8References method, and report back all reachable wrappers.
+   * Furthermore, the embedder is expected to stop tracing by the given
+   * deadline.
+   *
+   * Returns true if there is still work to do.
+   */
+  virtual bool AdvanceTracing(double deadline_in_ms,
+                              AdvanceTracingActions actions) = 0;
+
+  /**
+   * Called at the end of a GC cycle.
+   *
+   * Note that allocation is *not* allowed within |TraceEpilogue|.
+   */
+  virtual void TraceEpilogue() = 0;
+
+  /**
+   * Called upon entering the final marking pause. No more incremental marking
+   * steps will follow this call.
+   */
+  virtual void EnterFinalPause() = 0;
+
+  /**
+   * Called when tracing is aborted.
+   *
+   * The embedder is expected to throw away all intermediate data and reset to
+   * the initial state.
+   */
+  virtual void AbortTracing() = 0;
+
+  /**
+   * Returns the number of wrappers that are still to be traced by the embedder.
+   */
+  virtual size_t NumberOfWrappersToTrace() { return 0; }
+
+ protected:
+  virtual ~EmbedderHeapTracer() = default;
+};
+
+/**
+ * Callback and supporting data used in SnapshotCreator to implement embedder
+ * logic to serialize internal fields.
+ */
+struct SerializeInternalFieldsCallback {
+  typedef StartupData (*CallbackFunction)(Local<Object> holder, int index,
+                                          void* data);
+  SerializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                  void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  CallbackFunction callback;
+  void* data;
+};
+// Note that these fields are called "internal fields" in the API and called
+// "embedder fields" within V8.
+typedef SerializeInternalFieldsCallback SerializeEmbedderFieldsCallback;
+
+/**
+ * Callback and supporting data used to implement embedder logic to deserialize
+ * internal fields.
+ */
+struct DeserializeInternalFieldsCallback {
+  typedef void (*CallbackFunction)(Local<Object> holder, int index,
+                                   StartupData payload, void* data);
+  DeserializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                    void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  void (*callback)(Local<Object> holder, int index, StartupData payload,
+                   void* data);
+  void* data;
+};
+typedef DeserializeInternalFieldsCallback DeserializeEmbedderFieldsCallback;
+
+/**
+ * Isolate represents an isolated instance of the V8 engine.  V8 isolates have
+ * completely separate states.  Objects from one isolate must not be used in
+ * other isolates.  The embedder can create multiple isolates and use them in
+ * parallel in multiple threads.  An isolate can be entered by at most one
+ * thread at any given time.  The Locker/Unlocker API must be used to
+ * synchronize.
+ */
+class V8_EXPORT Isolate {
+ public:
+  /**
+   * Initial configuration parameters for a new Isolate.
+   */
+  struct CreateParams {
+    CreateParams()
+        : entry_hook(nullptr),
+          code_event_handler(nullptr),
+          snapshot_blob(nullptr),
+          counter_lookup_callback(nullptr),
+          create_histogram_callback(nullptr),
+          add_histogram_sample_callback(nullptr),
+          array_buffer_allocator(nullptr),
+          external_references(nullptr),
+          allow_atomics_wait(true),
+          host_import_module_dynamically_callback_(nullptr) {}
+
+    /**
+     * The optional entry_hook allows the host application to provide the
+     * address of a function that's invoked on entry to every V8-generated
+     * function.  Note that entry_hook is invoked at the very start of each
+     * generated function.
+     * An entry_hook can only be provided in no-snapshot builds; in snapshot
+     * builds it must be nullptr.
+     */
+    FunctionEntryHook entry_hook;
+
+    /**
+     * Allows the host application to provide the address of a function that is
+     * notified each time code is added, moved or removed.
+     */
+    JitCodeEventHandler code_event_handler;
+
+    /**
+     * ResourceConstraints to use for the new Isolate.
+     */
+    ResourceConstraints constraints;
+
+    /**
+     * Explicitly specify a startup snapshot blob. The embedder owns the blob.
+     */
+    StartupData* snapshot_blob;
+
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * statistics counters.
+     */
+    CounterLookupCallback counter_lookup_callback;
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * histograms. The CreateHistogram function returns a
+     * histogram which will later be passed to the AddHistogramSample
+     * function.
+     */
+    CreateHistogramCallback create_histogram_callback;
+    AddHistogramSampleCallback add_histogram_sample_callback;
+
+    /**
+     * The ArrayBuffer::Allocator to use for allocating and freeing the backing
+     * store of ArrayBuffers.
+     */
+    ArrayBuffer::Allocator* array_buffer_allocator;
+
+    /**
+     * Specifies an optional nullptr-terminated array of raw addresses in the
+     * embedder that V8 can match against during serialization and use for
+     * deserialization. This array and its content must stay valid for the
+     * entire lifetime of the isolate.
+     */
+    intptr_t* external_references;
+
+    /**
+     * Whether calling Atomics.wait (a function that may block) is allowed in
+     * this isolate. This can also be configured via SetAllowAtomicsWait.
+     */
+    bool allow_atomics_wait;
+
+    /**
+     * This is an unfinished experimental feature, and is only exposed
+     * here for internal testing purposes. DO NOT USE.
+     *
+     * This specifies the callback called by the upcoming dynamic
+     * import() language feature to load modules.
+     */
+    HostImportModuleDynamicallyCallback
+        host_import_module_dynamically_callback_;
+  };
+
+
+  /**
+   * Stack-allocated class which sets the isolate for all operations
+   * executed within a local scope.
+   */
+  class V8_EXPORT Scope {
+   public:
+    explicit Scope(Isolate* isolate) : isolate_(isolate) {
+      isolate->Enter();
+    }
+
+    ~Scope() { isolate_->Exit(); }
+
+    // Prevent copying of Scope objects.
+    Scope(const Scope&) = delete;
+    Scope& operator=(const Scope&) = delete;
+
+   private:
+    Isolate* const isolate_;
+  };
+
+
+  /**
+   * Assert that no Javascript code is invoked.
+   */
+  class V8_EXPORT DisallowJavascriptExecutionScope {
+   public:
+    enum OnFailure { CRASH_ON_FAILURE, THROW_ON_FAILURE };
+
+    DisallowJavascriptExecutionScope(Isolate* isolate, OnFailure on_failure);
+    ~DisallowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    DisallowJavascriptExecutionScope(const DisallowJavascriptExecutionScope&) =
+        delete;
+    DisallowJavascriptExecutionScope& operator=(
+        const DisallowJavascriptExecutionScope&) = delete;
+
+   private:
+    bool on_failure_;
+    void* internal_;
+  };
+
+
+  /**
+   * Introduce exception to DisallowJavascriptExecutionScope.
+   */
+  class V8_EXPORT AllowJavascriptExecutionScope {
+   public:
+    explicit AllowJavascriptExecutionScope(Isolate* isolate);
+    ~AllowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    AllowJavascriptExecutionScope(const AllowJavascriptExecutionScope&) =
+        delete;
+    AllowJavascriptExecutionScope& operator=(
+        const AllowJavascriptExecutionScope&) = delete;
+
+   private:
+    void* internal_throws_;
+    void* internal_assert_;
+  };
+
+  /**
+   * Do not run microtasks while this scope is active, even if microtasks are
+   * automatically executed otherwise.
+   */
+  class V8_EXPORT SuppressMicrotaskExecutionScope {
+   public:
+    explicit SuppressMicrotaskExecutionScope(Isolate* isolate);
+    ~SuppressMicrotaskExecutionScope();
+
+    // Prevent copying of Scope objects.
+    SuppressMicrotaskExecutionScope(const SuppressMicrotaskExecutionScope&) =
+        delete;
+    SuppressMicrotaskExecutionScope& operator=(
+        const SuppressMicrotaskExecutionScope&) = delete;
+
+   private:
+    internal::Isolate* const isolate_;
+  };
+
+  /**
+   * Types of garbage collections that can be requested via
+   * RequestGarbageCollectionForTesting.
+   */
+  enum GarbageCollectionType {
+    kFullGarbageCollection,
+    kMinorGarbageCollection
+  };
+
+  /**
+   * Features reported via the SetUseCounterCallback callback. Do not change
+   * assigned numbers of existing items; add new features to the end of this
+   * list.
+   */
+  enum UseCounterFeature {
+    kUseAsm = 0,
+    kBreakIterator = 1,
+    kLegacyConst = 2,
+    kMarkDequeOverflow = 3,
+    kStoreBufferOverflow = 4,
+    kSlotsBufferOverflow = 5,
+    kObjectObserve = 6,
+    kForcedGC = 7,
+    kSloppyMode = 8,
+    kStrictMode = 9,
+    kStrongMode = 10,
+    kRegExpPrototypeStickyGetter = 11,
+    kRegExpPrototypeToString = 12,
+    kRegExpPrototypeUnicodeGetter = 13,
+    kIntlV8Parse = 14,
+    kIntlPattern = 15,
+    kIntlResolved = 16,
+    kPromiseChain = 17,
+    kPromiseAccept = 18,
+    kPromiseDefer = 19,
+    kHtmlCommentInExternalScript = 20,
+    kHtmlComment = 21,
+    kSloppyModeBlockScopedFunctionRedefinition = 22,
+    kForInInitializer = 23,
+    kArrayProtectorDirtied = 24,
+    kArraySpeciesModified = 25,
+    kArrayPrototypeConstructorModified = 26,
+    kArrayInstanceProtoModified = 27,
+    kArrayInstanceConstructorModified = 28,
+    kLegacyFunctionDeclaration = 29,
+    kRegExpPrototypeSourceGetter = 30,
+    kRegExpPrototypeOldFlagGetter = 31,
+    kDecimalWithLeadingZeroInStrictMode = 32,
+    kLegacyDateParser = 33,
+    kDefineGetterOrSetterWouldThrow = 34,
+    kFunctionConstructorReturnedUndefined = 35,
+    kAssigmentExpressionLHSIsCallInSloppy = 36,
+    kAssigmentExpressionLHSIsCallInStrict = 37,
+    kPromiseConstructorReturnedUndefined = 38,
+
+    // If you add new values here, you'll also need to update Chromium's:
+    // UseCounter.h, V8PerIsolateData.cpp, histograms.xml
+    kUseCounterFeatureCount  // This enum value must be last.
+  };
+
+  enum MessageErrorLevel {
+    kMessageLog = (1 << 0),
+    kMessageDebug = (1 << 1),
+    kMessageInfo = (1 << 2),
+    kMessageError = (1 << 3),
+    kMessageWarning = (1 << 4),
+    kMessageAll = kMessageLog | kMessageDebug | kMessageInfo | kMessageError |
+                  kMessageWarning,
+  };
+
+  typedef void (*UseCounterCallback)(Isolate* isolate,
+                                     UseCounterFeature feature);
+
+
+  /**
+   * Creates a new isolate.  Does not change the currently entered
+   * isolate.
+   *
+   * When an isolate is no longer used its resources should be freed
+   * by calling Dispose().  Using the delete operator is not allowed.
+   *
+   * V8::Initialize() must have run prior to this.
+   */
+  static Isolate* New(const CreateParams& params);
+
+  /**
+   * Returns the entered isolate for the current thread or NULL in
+   * case there is no current isolate.
+   *
+   * This method must not be invoked before V8::Initialize() was invoked.
+   */
+  static Isolate* GetCurrent();
+
+  /**
+   * Custom callback used by embedders to help V8 determine if it should abort
+   * when it throws and no internal handler is predicted to catch the
+   * exception. If --abort-on-uncaught-exception is used on the command line,
+   * then V8 will abort if either:
+   * - no custom callback is set.
+   * - the custom callback set returns true.
+   * Otherwise, the custom callback will not be called and V8 will not abort.
+   */
+  typedef bool (*AbortOnUncaughtExceptionCallback)(Isolate*);
+  void SetAbortOnUncaughtExceptionCallback(
+      AbortOnUncaughtExceptionCallback callback);
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to guide heuristics.
+   * It is allowed to call this function from another thread while
+   * the isolate is executing long running JavaScript code.
+   */
+  void MemoryPressureNotification(MemoryPressureLevel level);
+
+  /**
+   * Methods below this point require holding a lock (using Locker) in
+   * a multi-threaded environment.
+   */
+
+  /**
+   * Sets this isolate as the entered one for the current thread.
+   * Saves the previously entered one (if any), so that it can be
+   * restored when exiting.  Re-entering an isolate is allowed.
+   */
+  void Enter();
+
+  /**
+   * Exits this isolate by restoring the previously entered one in the
+   * current thread.  The isolate may still stay the same, if it was
+   * entered more than once.
+   *
+   * Requires: this == Isolate::GetCurrent().
+   */
+  void Exit();
+
+  /**
+   * Disposes the isolate.  The isolate must not be entered by any
+   * thread to be disposable.
+   */
+  void Dispose();
+
+  /**
+   * Dumps activated low-level V8 internal stats. This can be used instead
+   * of performing a full isolate disposal.
+   */
+  void DumpAndResetStats();
+
+  /**
+   * Discards all V8 thread-specific data for the Isolate. Should be used
+   * if a thread is terminating and it has used an Isolate that will outlive
+   * the thread -- all thread-specific data for an Isolate is discarded when
+   * an Isolate is disposed so this call is pointless if an Isolate is about
+   * to be Disposed.
+   */
+  void DiscardThreadSpecificMetadata();
+
+  /**
+   * Associate embedder-specific data with the isolate. |slot| has to be
+   * between 0 and GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE void SetData(uint32_t slot, void* data);
+
+  /**
+   * Retrieve embedder-specific data from the isolate.
+   * Returns NULL if SetData has never been called for the given |slot|.
+   */
+  V8_INLINE void* GetData(uint32_t slot);
+
+  /**
+   * Returns the maximum number of available embedder data slots. Valid slots
+   * are in the range of 0 - GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE static uint32_t GetNumberOfDataSlots();
+
+  /**
+   * Get statistics about the heap memory usage.
+   */
+  void GetHeapStatistics(HeapStatistics* heap_statistics);
+
+  /**
+   * Returns the number of spaces in the heap.
+   */
+  size_t NumberOfHeapSpaces();
+
+  /**
+   * Get the memory usage of a space in the heap.
+   *
+   * \param space_statistics The HeapSpaceStatistics object to fill in
+   *   statistics.
+   * \param index The index of the space to get statistics from, which ranges
+   *   from 0 to NumberOfHeapSpaces() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapSpaceStatistics(HeapSpaceStatistics* space_statistics,
+                              size_t index);
+
+  /**
+   * Returns the number of types of objects tracked in the heap at GC.
+   */
+  size_t NumberOfTrackedHeapObjectTypes();
+
+  /**
+   * Get statistics about objects in the heap.
+   *
+   * \param object_statistics The HeapObjectStatistics object to fill in
+   *   statistics of objects of given type, which were live in the previous GC.
+   * \param type_index The index of the type of object to fill details about,
+   *   which ranges from 0 to NumberOfTrackedHeapObjectTypes() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapObjectStatisticsAtLastGC(HeapObjectStatistics* object_statistics,
+                                       size_t type_index);
+
+  /**
+   * Get statistics about code and its metadata in the heap.
+   *
+   * \param object_statistics The HeapCodeStatistics object to fill in
+   *   statistics of code, bytecode and their metadata.
+   * \returns true on success.
+   */
+  bool GetHeapCodeAndMetadataStatistics(HeapCodeStatistics* object_statistics);
+
+  /**
+   * Get a call stack sample from the isolate.
+   * \param state Execution state.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \note GetStackSample should only be called when the JS thread is paused or
+   *       interrupted. Otherwise the behavior is undefined.
+   */
+  void GetStackSample(const RegisterState& state, void** frames,
+                      size_t frames_limit, SampleInfo* sample_info);
+
+  /**
+   * Adjusts the amount of registered external memory. Used to give V8 an
+   * indication of the amount of externally allocated memory that is kept alive
+   * by JavaScript objects. V8 uses this to decide when to perform global
+   * garbage collections. Registering externally allocated memory will trigger
+   * global garbage collections more often than it would otherwise in an attempt
+   * to garbage collect the JavaScript objects that keep the externally
+   * allocated memory alive.
+   *
+   * \param change_in_bytes the change in externally allocated memory that is
+   *   kept alive by JavaScript objects.
+   * \returns the adjusted value.
+   */
+  V8_INLINE int64_t
+      AdjustAmountOfExternalAllocatedMemory(int64_t change_in_bytes);
+
+  /**
+   * Returns the number of phantom handles without callbacks that were reset
+   * by the garbage collector since the last call to this function.
+   */
+  size_t NumberOfPhantomHandleResetsSinceLastCall();
+
+  /**
+   * Returns heap profiler for this isolate. Will return NULL until the isolate
+   * is initialized.
+   */
+  HeapProfiler* GetHeapProfiler();
+
+  /**
+   * Returns CPU profiler for this isolate. Will return NULL unless the isolate
+   * is initialized. It is the embedder's responsibility to stop all CPU
+   * profiling activities if it has started any.
+   */
+  V8_DEPRECATE_SOON("CpuProfiler should be created with CpuProfiler::New call.",
+                    CpuProfiler* GetCpuProfiler());
+
+  /** Returns true if this isolate has a current context. */
+  bool InContext();
+
+  /**
+   * Returns the context of the currently running JavaScript, or the context
+   * on the top of the stack if no JavaScript is running.
+   */
+  Local<Context> GetCurrentContext();
+
+  /**
+   * Returns the context of the calling JavaScript code.  That is the
+   * context of the top-most JavaScript frame.  If there are no
+   * JavaScript frames an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON(
+      "Calling context concept is not compatible with tail calls, and will be "
+      "removed.",
+      Local<Context> GetCallingContext());
+
+  /** Returns the last context entered through V8's C++ API. */
+  Local<Context> GetEnteredContext();
+
+  /**
+   * Returns either the last context entered through V8's C++ API, or the
+   * context of the currently running microtask while processing microtasks.
+   * If a context is entered while executing a microtask, that context is
+   * returned.
+   */
+  Local<Context> GetEnteredOrMicrotaskContext();
+
+  /**
+   * Schedules an exception to be thrown when returning to JavaScript.  When an
+   * exception has been scheduled it is illegal to invoke any JavaScript
+   * operation; the caller must return immediately and only after the exception
+   * has been handled does it become legal to invoke JavaScript operations.
+   */
+  Local<Value> ThrowException(Local<Value> exception);
+
+  typedef void (*GCCallback)(Isolate* isolate, GCType type,
+                             GCCallbackFlags flags);
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCPrologueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  void RemoveGCPrologueCallback(GCCallback callback);
+
+  /**
+   * Sets the embedder heap tracer for the isolate.
+   */
+  void SetEmbedderHeapTracer(EmbedderHeapTracer* tracer);
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCEpilogueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  void RemoveGCEpilogueCallback(GCCallback callback);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void TerminateExecution();
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   */
+  bool IsExecutionTerminating();
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void CancelTerminateExecution();
+
+  /**
+   * Request V8 to interrupt long running JavaScript code and invoke
+   * the given |callback| passing the given |data| to it. After |callback|
+   * returns control will be returned to the JavaScript code.
+   * There may be a number of interrupt requests in flight.
+   * Can be called from another thread without acquiring a |Locker|.
+   * Registered |callback| must not reenter interrupted Isolate.
+   */
+  void RequestInterrupt(InterruptCallback callback, void* data);
+
+  /**
+   * Request garbage collection in this Isolate. It is only valid to call this
+   * function if --expose_gc was specified.
+   *
+   * This should only be used for testing purposes and not to enforce a garbage
+   * collection schedule. It has strong negative impact on the garbage
+   * collection performance. Use IdleNotificationDeadline() or
+   * LowMemoryNotification() instead to influence the garbage collection
+   * schedule.
+   */
+  void RequestGarbageCollectionForTesting(GarbageCollectionType type);
+
+  /**
+   * Set the callback to invoke for logging event.
+   */
+  void SetEventLogger(LogEventCallback that);
+
+  /**
+   * Adds a callback to notify the host application right before a script
+   * is about to run. If a script re-enters the runtime during executing, the
+   * BeforeCallEnteredCallback is invoked for each re-entrance.
+   * Executing scripts inside the callback will re-trigger the callback.
+   */
+  void AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Removes callback that was installed by AddBeforeCallEnteredCallback.
+   */
+  void RemoveBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Adds a callback to notify the host application when a script finished
+   * running.  If a script re-enters the runtime during executing, the
+   * CallCompletedCallback is only invoked when the outer-most script
+   * execution ends.  Executing scripts inside the callback do not trigger
+   * further callbacks.
+   */
+  void AddCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void AddCallCompletedCallback(DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Removes callback that was installed by AddCallCompletedCallback.
+   */
+  void RemoveCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void RemoveCallCompletedCallback(
+          DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Experimental: Set the PromiseHook callback for various promise
+   * lifecycle events.
+   */
+  void SetPromiseHook(PromiseHook hook);
+
+  /**
+   * Set callback to notify about promise reject with no handler, or
+   * revocation of such a previous notification once the handler is added.
+   */
+  void SetPromiseRejectCallback(PromiseRejectCallback callback);
+
+  /**
+   * Experimental: Runs the Microtask Work Queue until empty
+   * Any exceptions thrown by microtask callbacks are swallowed.
+   */
+  void RunMicrotasks();
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(Local<Function> microtask);
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(MicrotaskCallback microtask, void* data = NULL);
+
+  /**
+   * Experimental: Controls how Microtasks are invoked. See MicrotasksPolicy
+   * for details.
+   */
+  void SetMicrotasksPolicy(MicrotasksPolicy policy);
+  V8_DEPRECATE_SOON("Use SetMicrotasksPolicy",
+                    void SetAutorunMicrotasks(bool autorun));
+
+  /**
+   * Experimental: Returns the policy controlling how Microtasks are invoked.
+   */
+  MicrotasksPolicy GetMicrotasksPolicy() const;
+  V8_DEPRECATE_SOON("Use GetMicrotasksPolicy",
+                    bool WillAutorunMicrotasks() const);
+
+  /**
+   * Experimental: adds a callback to notify the host application after
+   * microtasks were run. The callback is triggered by explicit RunMicrotasks
+   * call or automatic microtasks execution (see SetAutorunMicrotasks).
+   *
+   * Callback will trigger even if microtasks were attempted to run,
+   * but the microtasks queue was empty and no single microtask was actually
+   * executed.
+   *
+   * Executing scriptsinside the callback will not re-trigger microtasks and
+   * the callback.
+   */
+  void AddMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Removes callback that was installed by AddMicrotasksCompletedCallback.
+   */
+  void RemoveMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Sets a callback for counting the number of times a feature of V8 is used.
+   */
+  void SetUseCounterCallback(UseCounterCallback callback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * statistics counters.
+   */
+  void SetCounterFunction(CounterLookupCallback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * histograms. The CreateHistogram function returns a
+   * histogram which will later be passed to the AddHistogramSample
+   * function.
+   */
+  void SetCreateHistogramFunction(CreateHistogramCallback);
+  void SetAddHistogramSampleFunction(AddHistogramSampleCallback);
+
+  /**
+   * Optional notification that the embedder is idle.
+   * V8 uses the notification to perform garbage collection.
+   * This call can be used repeatedly if the embedder remains idle.
+   * Returns true if the embedder should stop calling IdleNotificationDeadline
+   * until real work has been done.  This indicates that V8 has done
+   * as much cleanup as it will be able to do.
+   *
+   * The deadline_in_seconds argument specifies the deadline V8 has to finish
+   * garbage collection work. deadline_in_seconds is compared with
+   * MonotonicallyIncreasingTime() and should be based on the same timebase as
+   * that function. There is no guarantee that the actual work will be done
+   * within the time limit.
+   */
+  bool IdleNotificationDeadline(double deadline_in_seconds);
+
+  V8_DEPRECATED("use IdleNotificationDeadline()",
+                bool IdleNotification(int idle_time_in_ms));
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to attempt to free memory.
+   */
+  void LowMemoryNotification();
+
+  /**
+   * Optional notification that a context has been disposed. V8 uses
+   * these notifications to guide the GC heuristic. Returns the number
+   * of context disposals - including this one - since the last time
+   * V8 had a chance to clean up.
+   *
+   * The optional parameter |dependant_context| specifies whether the disposed
+   * context was depending on state from other contexts or not.
+   */
+  int ContextDisposedNotification(bool dependant_context = true);
+
+  /**
+   * Optional notification that the isolate switched to the foreground.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInForegroundNotification();
+
+  /**
+   * Optional notification that the isolate switched to the background.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInBackgroundNotification();
+
+  /**
+   * Optional notification to tell V8 the current performance requirements
+   * of the embedder based on RAIL.
+   * V8 uses these notifications to guide heuristics.
+   * This is an unfinished experimental feature. Semantics and implementation
+   * may change frequently.
+   */
+  void SetRAILMode(RAILMode rail_mode);
+
+  /**
+   * Optional notification to tell V8 the current isolate is used for debugging
+   * and requires higher heap limit.
+   */
+  void IncreaseHeapLimitForDebugging();
+
+  /**
+   * Restores the original heap limit after IncreaseHeapLimitForDebugging().
+   */
+  void RestoreOriginalHeapLimit();
+
+  /**
+   * Returns true if the heap limit was increased for debugging and the
+   * original heap limit was not restored yet.
+   */
+  bool IsHeapLimitIncreasedForDebugging();
+
+  /**
+   * Allows the host application to provide the address of a function that is
+   * notified each time code is added, moved or removed.
+   *
+   * \param options options for the JIT code event handler.
+   * \param event_handler the JIT code event handler, which will be invoked
+   *     each time code is added, moved or removed.
+   * \note \p event_handler won't get notified of existent code.
+   * \note since code removal notifications are not currently issued, the
+   *     \p event_handler may get notifications of code that overlaps earlier
+   *     code notifications. This happens when code areas are reused, and the
+   *     earlier overlapping code areas should therefore be discarded.
+   * \note the events passed to \p event_handler and the strings they point to
+   *     are not guaranteed to live past each call. The \p event_handler must
+   *     copy strings and other parameters it needs to keep around.
+   * \note the set of events declared in JitCodeEvent::EventType is expected to
+   *     grow over time, and the JitCodeEvent structure is expected to accrue
+   *     new members. The \p event_handler function must ignore event codes
+   *     it does not recognize to maintain future compatibility.
+   * \note Use Isolate::CreateParams to get events for code executed during
+   *     Isolate setup.
+   */
+  void SetJitCodeEventHandler(JitCodeEventOptions options,
+                              JitCodeEventHandler event_handler);
+
+  /**
+   * Modifies the stack limit for this Isolate.
+   *
+   * \param stack_limit An address beyond which the Vm's stack may not grow.
+   *
+   * \note  If you are using threads then you should hold the V8::Locker lock
+   *     while setting the stack limit and you must set a non-default stack
+   *     limit separately for each thread.
+   */
+  void SetStackLimit(uintptr_t stack_limit);
+
+  /**
+   * Returns a memory range that can potentially contain jitted code.
+   *
+   * On Win64, embedders are advised to install function table callbacks for
+   * these ranges, as default SEH won't be able to unwind through jitted code.
+   *
+   * The first page of the code range is reserved for the embedder and is
+   * committed, writable, and executable.
+   *
+   * Might be empty on other platforms.
+   *
+   * https://code.google.com/p/v8/issues/detail?id=3598
+   */
+  void GetCodeRange(void** start, size_t* length_in_bytes);
+
+  /** Set the callback to invoke in case of fatal errors. */
+  void SetFatalErrorHandler(FatalErrorCallback that);
+
+  /** Set the callback to invoke in case of OOM errors. */
+  void SetOOMErrorHandler(OOMErrorCallback that);
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  void SetAllowCodeGenerationFromStringsCallback(
+      AllowCodeGenerationFromStringsCallback callback);
+
+  /**
+   * Embedder over{ride|load} injection points for wasm APIs.
+   */
+  void SetWasmModuleCallback(ExtensionCallback callback);
+  void SetWasmCompileCallback(ExtensionCallback callback);
+  void SetWasmInstanceCallback(ExtensionCallback callback);
+  void SetWasmInstantiateCallback(ExtensionCallback callback);
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  bool IsDead();
+
+  /**
+   * Adds a message listener (errors only).
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  bool AddMessageListener(MessageCallback that,
+                          Local<Value> data = Local<Value>());
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   *
+   * A listener can listen for particular error levels by providing a mask.
+   */
+  bool AddMessageListenerWithErrorLevel(MessageCallback that,
+                                        int message_levels,
+                                        Local<Value> data = Local<Value>());
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  void RemoveMessageListeners(MessageCallback that);
+
+  /** Callback function for reporting failed access checks.*/
+  void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback);
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  void SetCaptureStackTraceForUncaughtExceptions(
+      bool capture, int frame_limit = 10,
+      StackTrace::StackTraceOptions options = StackTrace::kOverview);
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  void VisitExternalResources(ExternalResourceVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  void VisitHandlesForPartialDependence(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are weak to be marked as inactive if there is no
+   * pending activity for the handle.
+   */
+  void VisitWeakHandles(PersistentHandleVisitor* visitor);
+
+  /**
+   * Check if this isolate is in use.
+   * True if at least one thread Enter'ed this isolate.
+   */
+  bool IsInUse();
+
+  /**
+   * Set whether calling Atomics.wait (a function that may block) is allowed in
+   * this isolate. This can also be configured via
+   * CreateParams::allow_atomics_wait.
+   */
+  void SetAllowAtomicsWait(bool allow);
+
+  Isolate() = delete;
+  ~Isolate() = delete;
+  Isolate(const Isolate&) = delete;
+  Isolate& operator=(const Isolate&) = delete;
+  void* operator new(size_t size) = delete;
+  void operator delete(void*, size_t) = delete;
+
+ private:
+  template <class K, class V, class Traits>
+  friend class PersistentValueMapBase;
+
+  void ReportExternalAllocationLimitReached();
+};
+
+class V8_EXPORT StartupData {
+ public:
+  const char* data;
+  int raw_size;
+};
+
+
+/**
+ * EntropySource is used as a callback function when v8 needs a source
+ * of entropy.
+ */
+typedef bool (*EntropySource)(unsigned char* buffer, size_t length);
+
+/**
+ * ReturnAddressLocationResolver is used as a callback function when v8 is
+ * resolving the location of a return address on the stack. Profilers that
+ * change the return address on the stack can use this to resolve the stack
+ * location to whereever the profiler stashed the original return address.
+ *
+ * \param return_addr_location A location on stack where a machine
+ *    return address resides.
+ * \returns Either return_addr_location, or else a pointer to the profiler's
+ *    copy of the original return address.
+ *
+ * \note The resolver function must not cause garbage collection.
+ */
+typedef uintptr_t (*ReturnAddressLocationResolver)(
+    uintptr_t return_addr_location);
+
+
+/**
+ * Container class for static utility functions.
+ */
+class V8_EXPORT V8 {
+ public:
+  /** Set the callback to invoke in case of fatal errors. */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFatalErrorHandler(FatalErrorCallback that));
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void SetAllowCodeGenerationFromStringsCallback(
+                                 AllowCodeGenerationFromStringsCallback that));
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  V8_INLINE static V8_DEPRECATED("Use isolate version", bool IsDead());
+
+  /**
+   * Hand startup data to V8, in case the embedder has chosen to build
+   * V8 with external startup data.
+   *
+   * Note:
+   * - By default the startup data is linked into the V8 library, in which
+   *   case this function is not meaningful.
+   * - If this needs to be called, it needs to be called before V8
+   *   tries to make use of its built-ins.
+   * - To avoid unnecessary copies of data, V8 will point directly into the
+   *   given data blob, so pretty please keep it around until V8 exit.
+   * - Compression of the startup blob might be useful, but needs to
+   *   handled entirely on the embedders' side.
+   * - The call will abort if the data is invalid.
+   */
+  static void SetNativesDataBlob(StartupData* startup_blob);
+  static void SetSnapshotDataBlob(StartupData* startup_blob);
+
+  /**
+   * Bootstrap an isolate and a context from scratch to create a startup
+   * snapshot. Include the side-effects of running the optional script.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   */
+  static StartupData CreateSnapshotDataBlob(const char* embedded_source = NULL);
+
+  /**
+   * Bootstrap an isolate and a context from the cold startup blob, run the
+   * warm-up script to trigger code compilation. The side effects are then
+   * discarded. The resulting startup snapshot will include compiled code.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   * The argument startup blob is untouched.
+   */
+  static StartupData WarmUpSnapshotDataBlob(StartupData cold_startup_blob,
+                                            const char* warmup_source);
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool AddMessageListener(MessageCallback that,
+                              Local<Value> data = Local<Value>()));
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void RemoveMessageListeners(MessageCallback that));
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetCaptureStackTraceForUncaughtExceptions(
+          bool capture, int frame_limit = 10,
+          StackTrace::StackTraceOptions options = StackTrace::kOverview));
+
+  /**
+   * Sets V8 flags from a string.
+   */
+  static void SetFlagsFromString(const char* str, int length);
+
+  /**
+   * Sets V8 flags from the command line.
+   */
+  static void SetFlagsFromCommandLine(int* argc,
+                                      char** argv,
+                                      bool remove_flags);
+
+  /** Get the version string. */
+  static const char* GetVersion();
+
+  /** Callback function for reporting failed access checks.*/
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback));
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCPrologueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCPrologueCallback(GCCallback callback));
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCEpilogueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCEpilogueCallback(GCCallback callback));
+
+  /**
+   * Initializes V8. This function needs to be called before the first Isolate
+   * is created. It always returns true.
+   */
+  static bool Initialize();
+
+  /**
+   * Allows the host application to provide a callback which can be used
+   * as a source of entropy for random number generators.
+   */
+  static void SetEntropySource(EntropySource source);
+
+  /**
+   * Allows the host application to provide a callback that allows v8 to
+   * cooperate with a profiler that rewrites return addresses on stack.
+   */
+  static void SetReturnAddressLocationResolver(
+      ReturnAddressLocationResolver return_address_resolver);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to terminate the current JS execution.
+   */
+  V8_INLINE static V8_DEPRECATED("Use isolate version",
+                                 void TerminateExecution(Isolate* isolate));
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   *
+   * \param isolate The isolate in which to check.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool IsExecutionTerminating(Isolate* isolate = NULL));
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to resume execution capability.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void CancelTerminateExecution(Isolate* isolate));
+
+  /**
+   * Releases any resources used by v8 and stops any utility threads
+   * that may be running.  Note that disposing v8 is permanent, it
+   * cannot be reinitialized.
+   *
+   * It should generally not be necessary to dispose v8 before exiting
+   * a process, this should happen automatically.  It is only necessary
+   * to use if the process needs the resources taken up by v8.
+   */
+  static bool Dispose();
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitExternalResources(ExternalResourceVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in isolate's heap that have
+   * class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(Isolate* isolate,
+                                    PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesForPartialDependence(Isolate* isolate,
+                                            PersistentHandleVisitor* visitor));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. Returns true on success.
+   *
+   * If V8 was compiled with the ICU data in an external file, the location
+   * of the data file has to be provided.
+   */
+  V8_DEPRECATE_SOON(
+      "Use version with default location.",
+      static bool InitializeICU(const char* icu_data_file = nullptr));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. If V8 was compiled with
+   * the ICU data in an external file and when the default location of that
+   * file should be used, a path to the executable must be provided.
+   * Returns true on success.
+   *
+   * The default is a file called icudtl.dat side-by-side with the executable.
+   *
+   * Optionally, the location of the data file can be provided to override the
+   * default.
+   */
+  static bool InitializeICUDefaultLocation(const char* exec_path,
+                                           const char* icu_data_file = nullptr);
+
+  /**
+   * Initialize the external startup data. The embedder only needs to
+   * invoke this method when external startup data was enabled in a build.
+   *
+   * If V8 was compiled with the startup data in an external file, then
+   * V8 needs to be given those external files during startup. There are
+   * three ways to do this:
+   * - InitializeExternalStartupData(const char*)
+   *   This will look in the given directory for files "natives_blob.bin"
+   *   and "snapshot_blob.bin" - which is what the default build calls them.
+   * - InitializeExternalStartupData(const char*, const char*)
+   *   As above, but will directly use the two given file names.
+   * - Call SetNativesDataBlob, SetNativesDataBlob.
+   *   This will read the blobs from the given data structures and will
+   *   not perform any file IO.
+   */
+  static void InitializeExternalStartupData(const char* directory_path);
+  static void InitializeExternalStartupData(const char* natives_blob,
+                                            const char* snapshot_blob);
+  /**
+   * Sets the v8::Platform to use. This should be invoked before V8 is
+   * initialized.
+   */
+  static void InitializePlatform(Platform* platform);
+
+  /**
+   * Clears all references to the v8::Platform. This should be invoked after
+   * V8 was disposed.
+   */
+  static void ShutdownPlatform();
+
+#if V8_OS_LINUX && V8_TARGET_ARCH_X64 && !V8_OS_ANDROID
+  /**
+   * Give the V8 signal handler a chance to handle a fault.
+   *
+   * This function determines whether a memory access violation can be recovered
+   * by V8. If so, it will return true and modify context to return to a code
+   * fragment that can recover from the fault. Otherwise, TryHandleSignal will
+   * return false.
+   *
+   * The parameters to this function correspond to those passed to a Linux
+   * signal handler.
+   *
+   * \param signal_number The signal number.
+   *
+   * \param info A pointer to the siginfo_t structure provided to the signal
+   * handler.
+   *
+   * \param context The third argument passed to the Linux signal handler, which
+   * points to a ucontext_t structure.
+   */
+  static bool TryHandleSignal(int signal_number, void* info, void* context);
+#endif  // V8_OS_LINUX
+
+  /**
+   * Enable the default signal handler rather than using one provided by the
+   * embedder.
+   */
+  static bool RegisterDefaultSignalHandler();
+
+ private:
+  V8();
+
+  static internal::Object** GlobalizeReference(internal::Isolate* isolate,
+                                               internal::Object** handle);
+  static internal::Object** CopyPersistent(internal::Object** handle);
+  static void DisposeGlobal(internal::Object** global_handle);
+  static void MakeWeak(internal::Object** location, void* data,
+                       WeakCallbackInfo<void>::Callback weak_callback,
+                       WeakCallbackType type);
+  static void MakeWeak(internal::Object** location, void* data,
+                       // Must be 0 or -1.
+                       int internal_field_index1,
+                       // Must be 1 or -1.
+                       int internal_field_index2,
+                       WeakCallbackInfo<void>::Callback weak_callback);
+  static void MakeWeak(internal::Object*** location_addr);
+  static void* ClearWeak(internal::Object** location);
+  static Value* Eternalize(Isolate* isolate, Value* handle);
+
+  static void RegisterExternallyReferencedObject(internal::Object** object,
+                                                 internal::Isolate* isolate);
+
+  template <class K, class V, class T>
+  friend class PersistentValueMapBase;
+
+  static void FromJustIsNothing();
+  static void ToLocalEmpty();
+  static void InternalFieldOutOfBounds(int index);
+  template <class T> friend class Local;
+  template <class T>
+  friend class MaybeLocal;
+  template <class T>
+  friend class Maybe;
+  template <class T>
+  friend class WeakCallbackInfo;
+  template <class T> friend class Eternal;
+  template <class T> friend class PersistentBase;
+  template <class T, class M> friend class Persistent;
+  friend class Context;
+};
+
+/**
+ * Helper class to create a snapshot data blob.
+ */
+class V8_EXPORT SnapshotCreator {
+ public:
+  enum class FunctionCodeHandling { kClear, kKeep };
+
+  /**
+   * Create and enter an isolate, and set it up for serialization.
+   * The isolate is either created from scratch or from an existing snapshot.
+   * The caller keeps ownership of the argument snapshot.
+   * \param existing_blob existing snapshot from which to create this one.
+   * \param external_references a null-terminated array of external references
+   *        that must be equivalent to CreateParams::external_references.
+   */
+  SnapshotCreator(intptr_t* external_references = nullptr,
+                  StartupData* existing_blob = nullptr);
+
+  ~SnapshotCreator();
+
+  /**
+   * \returns the isolate prepared by the snapshot creator.
+   */
+  Isolate* GetIsolate();
+
+  /**
+   * Set the default context to be included in the snapshot blob.
+   * The snapshot will not contain the global proxy, and we expect one or a
+   * global object template to create one, to be provided upon deserialization.
+   */
+  void SetDefaultContext(Local<Context> context);
+
+  /**
+   * Add additional context to be included in the snapshot blob.
+   * The snapshot will include the global proxy.
+   *
+   * \param callback optional callback to serialize internal fields.
+   *
+   * \returns the index of the context in the snapshot blob.
+   */
+  size_t AddContext(Local<Context> context,
+                    SerializeInternalFieldsCallback callback =
+                        SerializeInternalFieldsCallback());
+
+  /**
+   * Add a template to be included in the snapshot blob.
+   * \returns the index of the template in the snapshot blob.
+   */
+  size_t AddTemplate(Local<Template> template_obj);
+
+  /**
+   * Created a snapshot data blob.
+   * This must not be called from within a handle scope.
+   * \param function_code_handling whether to include compiled function code
+   *        in the snapshot.
+   * \returns { nullptr, 0 } on failure, and a startup snapshot on success. The
+   *        caller acquires ownership of the data array in the return value.
+   */
+  StartupData CreateBlob(FunctionCodeHandling function_code_handling);
+
+  // Disallow copying and assigning.
+  SnapshotCreator(const SnapshotCreator&) = delete;
+  void operator=(const SnapshotCreator&) = delete;
+
+ private:
+  void* data_;
+};
+
+/**
+ * A simple Maybe type, representing an object which may or may not have a
+ * value, see https://hackage.haskell.org/package/base/docs/Data-Maybe.html.
+ *
+ * If an API method returns a Maybe<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, a
+ * "Nothing" value is returned.
+ */
+template <class T>
+class Maybe {
+ public:
+  V8_INLINE bool IsNothing() const { return !has_value_; }
+  V8_INLINE bool IsJust() const { return has_value_; }
+
+  /**
+   * An alias for |FromJust|. Will crash if the Maybe<> is nothing.
+   */
+  V8_INLINE T ToChecked() const { return FromJust(); }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), |false| is returned and |out| is left untouched.
+   */
+  V8_WARN_UNUSED_RESULT V8_INLINE bool To(T* out) const {
+    if (V8_LIKELY(IsJust())) *out = value_;
+    return IsJust();
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), V8 will crash the process.
+   */
+  V8_INLINE T FromJust() const {
+    if (V8_UNLIKELY(!IsJust())) V8::FromJustIsNothing();
+    return value_;
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T, using a default value if this
+   * Maybe<> is nothing (empty).
+   */
+  V8_INLINE T FromMaybe(const T& default_value) const {
+    return has_value_ ? value_ : default_value;
+  }
+
+  V8_INLINE bool operator==(const Maybe& other) const {
+    return (IsJust() == other.IsJust()) &&
+           (!IsJust() || FromJust() == other.FromJust());
+  }
+
+  V8_INLINE bool operator!=(const Maybe& other) const {
+    return !operator==(other);
+  }
+
+ private:
+  Maybe() : has_value_(false) {}
+  explicit Maybe(const T& t) : has_value_(true), value_(t) {}
+
+  bool has_value_;
+  T value_;
+
+  template <class U>
+  friend Maybe<U> Nothing();
+  template <class U>
+  friend Maybe<U> Just(const U& u);
+};
+
+
+template <class T>
+inline Maybe<T> Nothing() {
+  return Maybe<T>();
+}
+
+
+template <class T>
+inline Maybe<T> Just(const T& t) {
+  return Maybe<T>(t);
+}
+
+
+/**
+ * An external exception handler.
+ */
+class V8_EXPORT TryCatch {
+ public:
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  V8_DEPRECATED("Use isolate version", TryCatch());
+
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  TryCatch(Isolate* isolate);
+
+  /**
+   * Unregisters and deletes this try/catch block.
+   */
+  ~TryCatch();
+
+  /**
+   * Returns true if an exception has been caught by this try/catch block.
+   */
+  bool HasCaught() const;
+
+  /**
+   * For certain types of exceptions, it makes no sense to continue execution.
+   *
+   * If CanContinue returns false, the correct action is to perform any C++
+   * cleanup needed and then return.  If CanContinue returns false and
+   * HasTerminated returns true, it is possible to call
+   * CancelTerminateExecution in order to continue calling into the engine.
+   */
+  bool CanContinue() const;
+
+  /**
+   * Returns true if an exception has been caught due to script execution
+   * being terminated.
+   *
+   * There is no JavaScript representation of an execution termination
+   * exception.  Such exceptions are thrown when the TerminateExecution
+   * methods are called to terminate a long-running script.
+   *
+   * If such an exception has been thrown, HasTerminated will return true,
+   * indicating that it is possible to call CancelTerminateExecution in order
+   * to continue calling into the engine.
+   */
+  bool HasTerminated() const;
+
+  /**
+   * Throws the exception caught by this TryCatch in a way that avoids
+   * it being caught again by this same TryCatch.  As with ThrowException
+   * it is illegal to execute any JavaScript operations after calling
+   * ReThrow; the caller must return immediately to where the exception
+   * is caught.
+   */
+  Local<Value> ReThrow();
+
+  /**
+   * Returns the exception caught by this try/catch block.  If no exception has
+   * been caught an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been destroyed.
+   */
+  Local<Value> Exception() const;
+
+  /**
+   * Returns the .stack property of the thrown object.  If no .stack
+   * property is present an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON("Use maybe version.", Local<Value> StackTrace() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> StackTrace(
+      Local<Context> context) const;
+
+  /**
+   * Returns the message associated with this exception.  If there is
+   * no message associated an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been
+   * destroyed.
+   */
+  Local<v8::Message> Message() const;
+
+  /**
+   * Clears any exceptions that may have been caught by this try/catch block.
+   * After this method has been called, HasCaught() will return false. Cancels
+   * the scheduled exception if it is caught and ReThrow() is not called before.
+   *
+   * It is not necessary to clear a try/catch block before using it again; if
+   * another exception is thrown the previously caught exception will just be
+   * overwritten.  However, it is often a good idea since it makes it easier
+   * to determine which operation threw a given exception.
+   */
+  void Reset();
+
+  /**
+   * Set verbosity of the external exception handler.
+   *
+   * By default, exceptions that are caught by an external exception
+   * handler are not reported.  Call SetVerbose with true on an
+   * external exception handler to have exceptions caught by the
+   * handler reported as if they were not caught.
+   */
+  void SetVerbose(bool value);
+
+  /**
+   * Returns true if verbosity is enabled.
+   */
+  bool IsVerbose() const;
+
+  /**
+   * Set whether or not this TryCatch should capture a Message object
+   * which holds source information about where the exception
+   * occurred.  True by default.
+   */
+  void SetCaptureMessage(bool value);
+
+  /**
+   * There are cases when the raw address of C++ TryCatch object cannot be
+   * used for comparisons with addresses into the JS stack. The cases are:
+   * 1) ARM, ARM64 and MIPS simulators which have separate JS stack.
+   * 2) Address sanitizer allocates local C++ object in the heap when
+   *    UseAfterReturn mode is enabled.
+   * This method returns address that can be used for comparisons with
+   * addresses into the JS stack. When neither simulator nor ASAN's
+   * UseAfterReturn is enabled, then the address returned will be the address
+   * of the C++ try catch handler itself.
+   */
+  static void* JSStackComparableAddress(TryCatch* handler) {
+    if (handler == NULL) return NULL;
+    return handler->js_stack_comparable_address_;
+  }
+
+  TryCatch(const TryCatch&) = delete;
+  void operator=(const TryCatch&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  void ResetInternal();
+
+  internal::Isolate* isolate_;
+  TryCatch* next_;
+  void* exception_;
+  void* message_obj_;
+  void* js_stack_comparable_address_;
+  bool is_verbose_ : 1;
+  bool can_continue_ : 1;
+  bool capture_message_ : 1;
+  bool rethrow_ : 1;
+  bool has_terminated_ : 1;
+
+  friend class internal::Isolate;
+};
+
+
+// --- Context ---
+
+
+/**
+ * A container for extension names.
+ */
+class V8_EXPORT ExtensionConfiguration {
+ public:
+  ExtensionConfiguration() : name_count_(0), names_(NULL) { }
+  ExtensionConfiguration(int name_count, const char* names[])
+      : name_count_(name_count), names_(names) { }
+
+  const char** begin() const { return &names_[0]; }
+  const char** end()  const { return &names_[name_count_]; }
+
+ private:
+  const int name_count_;
+  const char** names_;
+};
+
+/**
+ * A sandboxed execution context with its own set of built-in objects
+ * and functions.
+ */
+class V8_EXPORT Context {
+ public:
+  /**
+   * Returns the global proxy object.
+   *
+   * Global proxy object is a thin wrapper whose prototype points to actual
+   * context's global object with the properties like Object, etc. This is done
+   * that way for security reasons (for more details see
+   * https://wiki.mozilla.org/Gecko:SplitWindow).
+   *
+   * Please note that changes to global proxy object prototype most probably
+   * would break VM---v8 expects only global object as a prototype of global
+   * proxy object.
+   */
+  Local<Object> Global();
+
+  /**
+   * Detaches the global object from its context before
+   * the global object can be reused to create a new context.
+   */
+  void DetachGlobal();
+
+  /**
+   * Creates a new context and returns a handle to the newly allocated
+   * context.
+   *
+   * \param isolate The isolate in which to create the context.
+   *
+   * \param extensions An optional extension configuration containing
+   * the extensions to be installed in the newly created context.
+   *
+   * \param global_template An optional object template from which the
+   * global object for the newly created context will be created.
+   *
+   * \param global_object An optional global object to be reused for
+   * the newly created context. This global object must have been
+   * created by a previous call to Context::New with the same global
+   * template. The state of the global object will be completely reset
+   * and only object identify will remain.
+   */
+  static Local<Context> New(
+      Isolate* isolate, ExtensionConfiguration* extensions = NULL,
+      MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Create a new context from a (non-default) context snapshot. There
+   * is no way to provide a global object template since we do not create
+   * a new global object from template, but we can reuse a global object.
+   *
+   * \param isolate See v8::Context::New.
+   *
+   * \param context_snapshot_index The index of the context snapshot to
+   * deserialize from. Use v8::Context::New for the default snapshot.
+   *
+   * \param embedder_fields_deserializer Optional callback to deserialize
+   * internal fields. It should match the SerializeInternalFieldCallback used
+   * to serialize.
+   *
+   * \param extensions See v8::Context::New.
+   *
+   * \param global_object See v8::Context::New.
+   */
+
+  static MaybeLocal<Context> FromSnapshot(
+      Isolate* isolate, size_t context_snapshot_index,
+      DeserializeInternalFieldsCallback embedder_fields_deserializer =
+          DeserializeInternalFieldsCallback(),
+      ExtensionConfiguration* extensions = nullptr,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Returns an global object that isn't backed by an actual context.
+   *
+   * The global template needs to have access checks with handlers installed.
+   * If an existing global object is passed in, the global object is detached
+   * from its context.
+   *
+   * Note that this is different from a detached context where all accesses to
+   * the global proxy will fail. Instead, the access check handlers are invoked.
+   *
+   * It is also not possible to detach an object returned by this method.
+   * Instead, the access check handlers need to return nothing to achieve the
+   * same effect.
+   *
+   * It is possible, however, to create a new context from the global object
+   * returned by this method.
+   */
+  static MaybeLocal<Object> NewRemoteContext(
+      Isolate* isolate, Local<ObjectTemplate> global_template,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Sets the security token for the context.  To access an object in
+   * another context, the security tokens must match.
+   */
+  void SetSecurityToken(Local<Value> token);
+
+  /** Restores the security token to the default value. */
+  void UseDefaultSecurityToken();
+
+  /** Returns the security token of this context.*/
+  Local<Value> GetSecurityToken();
+
+  /**
+   * Enter this context.  After entering a context, all code compiled
+   * and run is compiled and run in this context.  If another context
+   * is already entered, this old context is saved so it can be
+   * restored when the new context is exited.
+   */
+  void Enter();
+
+  /**
+   * Exit this context.  Exiting the current context restores the
+   * context that was in place when entering the current context.
+   */
+  void Exit();
+
+  /** Returns an isolate associated with a current context. */
+  Isolate* GetIsolate();
+
+  /**
+   * The field at kDebugIdIndex used to be reserved for the inspector.
+   * It now serves no purpose.
+   */
+  enum EmbedderDataFields { kDebugIdIndex = 0 };
+
+  /**
+   * Gets the embedder data with the given index, which must have been set by a
+   * previous call to SetEmbedderData with the same index.
+   */
+  V8_INLINE Local<Value> GetEmbedderData(int index);
+
+  /**
+   * Gets the binding object used by V8 extras. Extra natives get a reference
+   * to this object and can use it to "export" functionality by adding
+   * properties. Extra natives can also "import" functionality by accessing
+   * properties added by the embedder using the V8 API.
+   */
+  Local<Object> GetExtrasBindingObject();
+
+  /**
+   * Sets the embedder data with the given index, growing the data as
+   * needed. Note that index 0 currently has a special meaning for Chrome's
+   * debugger.
+   */
+  void SetEmbedderData(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from the embedder data with the given
+   * index, which must have been set by a previous call to
+   * SetAlignedPointerInEmbedderData with the same index. Note that index 0
+   * currently has a special meaning for Chrome's debugger.
+   */
+  V8_INLINE void* GetAlignedPointerFromEmbedderData(int index);
+
+  /**
+   * Sets a 2-byte-aligned native pointer in the embedder data with the given
+   * index, growing the data as needed. Note that index 0 currently has a
+   * special meaning for Chrome's debugger.
+   */
+  void SetAlignedPointerInEmbedderData(int index, void* value);
+
+  /**
+   * Control whether code generation from strings is allowed. Calling
+   * this method with false will disable 'eval' and the 'Function'
+   * constructor for code running in this context. If 'eval' or the
+   * 'Function' constructor are used an exception will be thrown.
+   *
+   * If code generation from strings is not allowed the
+   * V8::AllowCodeGenerationFromStrings callback will be invoked if
+   * set before blocking the call to 'eval' or the 'Function'
+   * constructor. If that callback returns true, the call will be
+   * allowed, otherwise an exception will be thrown. If no callback is
+   * set an exception will be thrown.
+   */
+  void AllowCodeGenerationFromStrings(bool allow);
+
+  /**
+   * Returns true if code generation from strings is allowed for the context.
+   * For more details see AllowCodeGenerationFromStrings(bool) documentation.
+   */
+  bool IsCodeGenerationFromStringsAllowed();
+
+  /**
+   * Sets the error description for the exception that is thrown when
+   * code generation from strings is not allowed and 'eval' or the 'Function'
+   * constructor are called.
+   */
+  void SetErrorMessageForCodeGenerationFromStrings(Local<String> message);
+
+  /**
+   * Estimate the memory in bytes retained by this context.
+   */
+  V8_DEPRECATED("no longer supported", size_t EstimatedSize());
+
+  /**
+   * Stack-allocated class which sets the execution context for all
+   * operations executed within a local scope.
+   */
+  class Scope {
+   public:
+    explicit V8_INLINE Scope(Local<Context> context) : context_(context) {
+      context_->Enter();
+    }
+    V8_INLINE ~Scope() { context_->Exit(); }
+
+   private:
+    Local<Context> context_;
+  };
+
+ private:
+  friend class Value;
+  friend class Script;
+  friend class Object;
+  friend class Function;
+
+  Local<Value> SlowGetEmbedderData(int index);
+  void* SlowGetAlignedPointerFromEmbedderData(int index);
+};
+
+
+/**
+ * Multiple threads in V8 are allowed, but only one thread at a time is allowed
+ * to use any given V8 isolate, see the comments in the Isolate class. The
+ * definition of 'using a V8 isolate' includes accessing handles or holding onto
+ * object pointers obtained from V8 handles while in the particular V8 isolate.
+ * It is up to the user of V8 to ensure, perhaps with locking, that this
+ * constraint is not violated. In addition to any other synchronization
+ * mechanism that may be used, the v8::Locker and v8::Unlocker classes must be
+ * used to signal thread switches to V8.
+ *
+ * v8::Locker is a scoped lock object. While it's active, i.e. between its
+ * construction and destruction, the current thread is allowed to use the locked
+ * isolate. V8 guarantees that an isolate can be locked by at most one thread at
+ * any time. In other words, the scope of a v8::Locker is a critical section.
+ *
+ * Sample usage:
+* \code
+ * ...
+ * {
+ *   v8::Locker locker(isolate);
+ *   v8::Isolate::Scope isolate_scope(isolate);
+ *   ...
+ *   // Code using V8 and isolate goes here.
+ *   ...
+ * } // Destructor called here
+ * \endcode
+ *
+ * If you wish to stop using V8 in a thread A you can do this either by
+ * destroying the v8::Locker object as above or by constructing a v8::Unlocker
+ * object:
+ *
+ * \code
+ * {
+ *   isolate->Exit();
+ *   v8::Unlocker unlocker(isolate);
+ *   ...
+ *   // Code not using V8 goes here while V8 can run in another thread.
+ *   ...
+ * } // Destructor called here.
+ * isolate->Enter();
+ * \endcode
+ *
+ * The Unlocker object is intended for use in a long-running callback from V8,
+ * where you want to release the V8 lock for other threads to use.
+ *
+ * The v8::Locker is a recursive lock, i.e. you can lock more than once in a
+ * given thread. This can be useful if you have code that can be called either
+ * from code that holds the lock or from code that does not. The Unlocker is
+ * not recursive so you can not have several Unlockers on the stack at once, and
+ * you can not use an Unlocker in a thread that is not inside a Locker's scope.
+ *
+ * An unlocker will unlock several lockers if it has to and reinstate the
+ * correct depth of locking on its destruction, e.g.:
+ *
+ * \code
+ * // V8 not locked.
+ * {
+ *   v8::Locker locker(isolate);
+ *   Isolate::Scope isolate_scope(isolate);
+ *   // V8 locked.
+ *   {
+ *     v8::Locker another_locker(isolate);
+ *     // V8 still locked (2 levels).
+ *     {
+ *       isolate->Exit();
+ *       v8::Unlocker unlocker(isolate);
+ *       // V8 not locked.
+ *     }
+ *     isolate->Enter();
+ *     // V8 locked again (2 levels).
+ *   }
+ *   // V8 still locked (1 level).
+ * }
+ * // V8 Now no longer locked.
+ * \endcode
+ */
+class V8_EXPORT Unlocker {
+ public:
+  /**
+   * Initialize Unlocker for a given Isolate.
+   */
+  V8_INLINE explicit Unlocker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Unlocker();
+ private:
+  void Initialize(Isolate* isolate);
+
+  internal::Isolate* isolate_;
+};
+
+
+class V8_EXPORT Locker {
+ public:
+  /**
+   * Initialize Locker for a given Isolate.
+   */
+  V8_INLINE explicit Locker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Locker();
+
+  /**
+   * Returns whether or not the locker for a given isolate, is locked by the
+   * current thread.
+   */
+  static bool IsLocked(Isolate* isolate);
+
+  /**
+   * Returns whether v8::Locker is being used by this V8 instance.
+   */
+  static bool IsActive();
+
+  // Disallow copying and assigning.
+  Locker(const Locker&) = delete;
+  void operator=(const Locker&) = delete;
+
+ private:
+  void Initialize(Isolate* isolate);
+
+  bool has_lock_;
+  bool top_level_;
+  internal::Isolate* isolate_;
+};
+
+
+// --- Implementation ---
+
+
+namespace internal {
+
+const int kApiPointerSize = sizeof(void*);  // NOLINT
+const int kApiIntSize = sizeof(int);  // NOLINT
+const int kApiInt64Size = sizeof(int64_t);  // NOLINT
+
+// Tag information for HeapObject.
+const int kHeapObjectTag = 1;
+const int kHeapObjectTagSize = 2;
+const intptr_t kHeapObjectTagMask = (1 << kHeapObjectTagSize) - 1;
+
+// Tag information for Smi.
+const int kSmiTag = 0;
+const int kSmiTagSize = 1;
+const intptr_t kSmiTagMask = (1 << kSmiTagSize) - 1;
+
+template <size_t ptr_size> struct SmiTagging;
+
+template<int kSmiShiftSize>
+V8_INLINE internal::Object* IntToSmi(int value) {
+  int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
+  uintptr_t tagged_value =
+      (static_cast<uintptr_t>(value) << smi_shift_bits) | kSmiTag;
+  return reinterpret_cast<internal::Object*>(tagged_value);
+}
+
+// Smi constants for 32-bit systems.
+template <> struct SmiTagging<4> {
+  enum { kSmiShiftSize = 0, kSmiValueSize = 31 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Throw away top 32 bits and shift down (requires >> to be sign extending).
+    return static_cast<int>(reinterpret_cast<intptr_t>(value)) >> shift_bits;
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as an tagged small integer, the two
+    // most-significant bits of 'value' must be either 00 or 11 due to
+    // sign-extension. To check this we add 01 to the two
+    // most-significant bits, and check if the most-significant bit is 0
+    //
+    // CAUTION: The original code below:
+    // bool result = ((value + 0x40000000) & 0x80000000) == 0;
+    // may lead to incorrect results according to the C language spec, and
+    // in fact doesn't work correctly with gcc4.1.1 in some cases: The
+    // compiler may produce undefined results in case of signed integer
+    // overflow. The computation must be done w/ unsigned ints.
+    return static_cast<uintptr_t>(value + 0x40000000U) < 0x80000000U;
+  }
+};
+
+// Smi constants for 64-bit systems.
+template <> struct SmiTagging<8> {
+  enum { kSmiShiftSize = 31, kSmiValueSize = 32 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Shift down and throw away top 32 bits.
+    return static_cast<int>(reinterpret_cast<intptr_t>(value) >> shift_bits);
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as a long smi, the value must be a 32-bit integer.
+    return (value == static_cast<int32_t>(value));
+  }
+};
+
+typedef SmiTagging<kApiPointerSize> PlatformSmiTagging;
+const int kSmiShiftSize = PlatformSmiTagging::kSmiShiftSize;
+const int kSmiValueSize = PlatformSmiTagging::kSmiValueSize;
+V8_INLINE static bool SmiValuesAre31Bits() { return kSmiValueSize == 31; }
+V8_INLINE static bool SmiValuesAre32Bits() { return kSmiValueSize == 32; }
+
+/**
+ * This class exports constants and functionality from within v8 that
+ * is necessary to implement inline functions in the v8 api.  Don't
+ * depend on functions and constants defined here.
+ */
+class Internals {
+ public:
+  // These values match non-compiler-dependent values defined within
+  // the implementation of v8.
+  static const int kHeapObjectMapOffset = 0;
+  static const int kMapInstanceTypeAndBitFieldOffset =
+      1 * kApiPointerSize + kApiIntSize;
+  static const int kStringResourceOffset = 3 * kApiPointerSize;
+
+  static const int kOddballKindOffset = 4 * kApiPointerSize + sizeof(double);
+  static const int kForeignAddressOffset = kApiPointerSize;
+  static const int kJSObjectHeaderSize = 3 * kApiPointerSize;
+  static const int kFixedArrayHeaderSize = 2 * kApiPointerSize;
+  static const int kContextHeaderSize = 2 * kApiPointerSize;
+  static const int kContextEmbedderDataIndex = 5;
+  static const int kFullStringRepresentationMask = 0x0f;
+  static const int kStringEncodingMask = 0x8;
+  static const int kExternalTwoByteRepresentationTag = 0x02;
+  static const int kExternalOneByteRepresentationTag = 0x0a;
+
+  static const int kIsolateEmbedderDataOffset = 0 * kApiPointerSize;
+  static const int kExternalMemoryOffset = 4 * kApiPointerSize;
+  static const int kExternalMemoryLimitOffset =
+      kExternalMemoryOffset + kApiInt64Size;
+  static const int kIsolateRootsOffset = kExternalMemoryLimitOffset +
+                                         kApiInt64Size + kApiInt64Size +
+                                         kApiPointerSize + kApiPointerSize;
+  static const int kUndefinedValueRootIndex = 4;
+  static const int kTheHoleValueRootIndex = 5;
+  static const int kNullValueRootIndex = 6;
+  static const int kTrueValueRootIndex = 7;
+  static const int kFalseValueRootIndex = 8;
+  static const int kEmptyStringRootIndex = 9;
+
+  static const int kNodeClassIdOffset = 1 * kApiPointerSize;
+  static const int kNodeFlagsOffset = 1 * kApiPointerSize + 3;
+  static const int kNodeStateMask = 0x7;
+  static const int kNodeStateIsWeakValue = 2;
+  static const int kNodeStateIsPendingValue = 3;
+  static const int kNodeStateIsNearDeathValue = 4;
+  static const int kNodeIsIndependentShift = 3;
+  static const int kNodeIsActiveShift = 4;
+
+  static const int kJSApiObjectType = 0xbb;
+  static const int kJSObjectType = 0xbc;
+  static const int kFirstNonstringType = 0x80;
+  static const int kOddballType = 0x82;
+  static const int kForeignType = 0x86;
+
+  static const int kUndefinedOddballKind = 5;
+  static const int kNullOddballKind = 3;
+
+  static const uint32_t kNumIsolateDataSlots = 4;
+
+  V8_EXPORT static void CheckInitializedImpl(v8::Isolate* isolate);
+  V8_INLINE static void CheckInitialized(v8::Isolate* isolate) {
+#ifdef V8_ENABLE_CHECKS
+    CheckInitializedImpl(isolate);
+#endif
+  }
+
+  V8_INLINE static bool HasHeapObjectTag(const internal::Object* value) {
+    return ((reinterpret_cast<intptr_t>(value) & kHeapObjectTagMask) ==
+            kHeapObjectTag);
+  }
+
+  V8_INLINE static int SmiValue(const internal::Object* value) {
+    return PlatformSmiTagging::SmiToInt(value);
+  }
+
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return PlatformSmiTagging::IntToSmi(value);
+  }
+
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    return PlatformSmiTagging::IsValidSmi(value);
+  }
+
+  V8_INLINE static int GetInstanceType(const internal::Object* obj) {
+    typedef internal::Object O;
+    O* map = ReadField<O*>(obj, kHeapObjectMapOffset);
+    // Map::InstanceType is defined so that it will always be loaded into
+    // the LS 8 bits of one 16-bit word, regardless of endianess.
+    return ReadField<uint16_t>(map, kMapInstanceTypeAndBitFieldOffset) & 0xff;
+  }
+
+  V8_INLINE static int GetOddballKind(const internal::Object* obj) {
+    typedef internal::Object O;
+    return SmiValue(ReadField<O*>(obj, kOddballKindOffset));
+  }
+
+  V8_INLINE static bool IsExternalTwoByteString(int instance_type) {
+    int representation = (instance_type & kFullStringRepresentationMask);
+    return representation == kExternalTwoByteRepresentationTag;
+  }
+
+  V8_INLINE static uint8_t GetNodeFlag(internal::Object** obj, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      return *addr & static_cast<uint8_t>(1U << shift);
+  }
+
+  V8_INLINE static void UpdateNodeFlag(internal::Object** obj,
+                                       bool value, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      uint8_t mask = static_cast<uint8_t>(1U << shift);
+      *addr = static_cast<uint8_t>((*addr & ~mask) | (value << shift));
+  }
+
+  V8_INLINE static uint8_t GetNodeState(internal::Object** obj) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    return *addr & kNodeStateMask;
+  }
+
+  V8_INLINE static void UpdateNodeState(internal::Object** obj,
+                                        uint8_t value) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    *addr = static_cast<uint8_t>((*addr & ~kNodeStateMask) | value);
+  }
+
+  V8_INLINE static void SetEmbedderData(v8::Isolate* isolate,
+                                        uint32_t slot,
+                                        void* data) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) +
+                    kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    *reinterpret_cast<void**>(addr) = data;
+  }
+
+  V8_INLINE static void* GetEmbedderData(const v8::Isolate* isolate,
+                                         uint32_t slot) {
+    const uint8_t* addr = reinterpret_cast<const uint8_t*>(isolate) +
+        kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    return *reinterpret_cast<void* const*>(addr);
+  }
+
+  V8_INLINE static internal::Object** GetRoot(v8::Isolate* isolate,
+                                              int index) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) + kIsolateRootsOffset;
+    return reinterpret_cast<internal::Object**>(addr + index * kApiPointerSize);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadField(const internal::Object* ptr, int offset) {
+    const uint8_t* addr =
+        reinterpret_cast<const uint8_t*>(ptr) + offset - kHeapObjectTag;
+    return *reinterpret_cast<const T*>(addr);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadEmbedderData(const v8::Context* context, int index) {
+    typedef internal::Object O;
+    typedef internal::Internals I;
+    O* ctx = *reinterpret_cast<O* const*>(context);
+    int embedder_data_offset = I::kContextHeaderSize +
+        (internal::kApiPointerSize * I::kContextEmbedderDataIndex);
+    O* embedder_data = I::ReadField<O*>(ctx, embedder_data_offset);
+    int value_offset =
+        I::kFixedArrayHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<T>(embedder_data, value_offset);
+  }
+};
+
+}  // namespace internal
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, Local<T> that) {
+  return New(isolate, that.val_);
+}
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, const PersistentBase<T>& that) {
+  return New(isolate, that.val_);
+}
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return Local<T>();
+  T* that_ptr = that;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that_ptr);
+  return Local<T>(reinterpret_cast<T*>(HandleScope::CreateHandle(
+      reinterpret_cast<internal::Isolate*>(isolate), *p)));
+}
+
+
+template<class T>
+template<class S>
+void Eternal<T>::Set(Isolate* isolate, Local<S> handle) {
+  TYPE_CHECK(T, S);
+  val_ = reinterpret_cast<T*>(
+      V8::Eternalize(isolate, reinterpret_cast<Value*>(*handle)));
+}
+
+template <class T>
+Local<T> Eternal<T>::Get(Isolate* isolate) const {
+  // The eternal handle will never go away, so as with the roots, we don't even
+  // need to open a handle.
+  return Local<T>(val_);
+}
+
+
+template <class T>
+Local<T> MaybeLocal<T>::ToLocalChecked() {
+  if (V8_UNLIKELY(val_ == nullptr)) V8::ToLocalEmpty();
+  return Local<T>(val_);
+}
+
+
+template <class T>
+void* WeakCallbackInfo<T>::GetInternalField(int index) const {
+#ifdef V8_ENABLE_CHECKS
+  if (index < 0 || index >= kEmbedderFieldsInWeakCallback) {
+    V8::InternalFieldOutOfBounds(index);
+  }
+#endif
+  return embedder_fields_[index];
+}
+
+
+template <class T>
+T* PersistentBase<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return NULL;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that);
+  return reinterpret_cast<T*>(
+      V8::GlobalizeReference(reinterpret_cast<internal::Isolate*>(isolate),
+                             p));
+}
+
+
+template <class T, class M>
+template <class S, class M2>
+void Persistent<T, M>::Copy(const Persistent<S, M2>& that) {
+  TYPE_CHECK(T, S);
+  this->Reset();
+  if (that.IsEmpty()) return;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that.val_);
+  this->val_ = reinterpret_cast<T*>(V8::CopyPersistent(p));
+  M::Copy(that, this);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsIndependent() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                        I::kNodeIsIndependentShift);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsNearDeath() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  uint8_t node_state =
+      I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_));
+  return node_state == I::kNodeStateIsNearDeathValue ||
+      node_state == I::kNodeStateIsPendingValue;
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsWeak() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_)) ==
+      I::kNodeStateIsWeakValue;
+}
+
+
+template <class T>
+void PersistentBase<T>::Reset() {
+  if (this->IsEmpty()) return;
+  V8::DisposeGlobal(reinterpret_cast<internal::Object**>(this->val_));
+  val_ = 0;
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate, const Local<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate,
+                              const PersistentBase<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <typename P>
+V8_INLINE void PersistentBase<T>::SetWeak(
+    P* parameter, typename WeakCallbackInfo<P>::Callback callback,
+    WeakCallbackType type) {
+  typedef typename WeakCallbackInfo<void>::Callback Callback;
+  V8::MakeWeak(reinterpret_cast<internal::Object**>(this->val_), parameter,
+               reinterpret_cast<Callback>(callback), type);
+}
+
+template <class T>
+void PersistentBase<T>::SetWeak() {
+  V8::MakeWeak(reinterpret_cast<internal::Object***>(&this->val_));
+}
+
+template <class T>
+template <typename P>
+P* PersistentBase<T>::ClearWeak() {
+  return reinterpret_cast<P*>(
+    V8::ClearWeak(reinterpret_cast<internal::Object**>(this->val_)));
+}
+
+template <class T>
+void PersistentBase<T>::RegisterExternalReference(Isolate* isolate) const {
+  if (IsEmpty()) return;
+  V8::RegisterExternallyReferencedObject(
+      reinterpret_cast<internal::Object**>(this->val_),
+      reinterpret_cast<internal::Isolate*>(isolate));
+}
+
+template <class T>
+void PersistentBase<T>::MarkIndependent() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                    true,
+                    I::kNodeIsIndependentShift);
+}
+
+template <class T>
+void PersistentBase<T>::MarkActive() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_), true,
+                    I::kNodeIsActiveShift);
+}
+
+
+template <class T>
+void PersistentBase<T>::SetWrapperClassId(uint16_t class_id) {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  *reinterpret_cast<uint16_t*>(addr) = class_id;
+}
+
+
+template <class T>
+uint16_t PersistentBase<T>::WrapperClassId() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return 0;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  return *reinterpret_cast<uint16_t*>(addr);
+}
+
+
+template<typename T>
+ReturnValue<T>::ReturnValue(internal::Object** slot) : value_(slot) {}
+
+template<typename T>
+template<typename S>
+void ReturnValue<T>::Set(const Persistent<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Global<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Local<S> handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template<typename T>
+void ReturnValue<T>::Set(double i) {
+  TYPE_CHECK(T, Number);
+  Set(Number::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(int32_t i) {
+  TYPE_CHECK(T, Integer);
+  typedef internal::Internals I;
+  if (V8_LIKELY(I::IsValidSmi(i))) {
+    *value_ = I::IntToSmi(i);
+    return;
+  }
+  Set(Integer::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(uint32_t i) {
+  TYPE_CHECK(T, Integer);
+  // Can't simply use INT32_MAX here for whatever reason.
+  bool fits_into_int32_t = (i & (1U << 31)) == 0;
+  if (V8_LIKELY(fits_into_int32_t)) {
+    Set(static_cast<int32_t>(i));
+    return;
+  }
+  Set(Integer::NewFromUnsigned(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(bool value) {
+  TYPE_CHECK(T, Boolean);
+  typedef internal::Internals I;
+  int root_index;
+  if (value) {
+    root_index = I::kTrueValueRootIndex;
+  } else {
+    root_index = I::kFalseValueRootIndex;
+  }
+  *value_ = *I::GetRoot(GetIsolate(), root_index);
+}
+
+template<typename T>
+void ReturnValue<T>::SetNull() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kNullValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetUndefined() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kUndefinedValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetEmptyString() {
+  TYPE_CHECK(T, String);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kEmptyStringRootIndex);
+}
+
+template <typename T>
+Isolate* ReturnValue<T>::GetIsolate() const {
+  // Isolate is always the pointer below the default value on the stack.
+  return *reinterpret_cast<Isolate**>(&value_[-2]);
+}
+
+template <typename T>
+Local<Value> ReturnValue<T>::Get() const {
+  typedef internal::Internals I;
+  if (*value_ == *I::GetRoot(GetIsolate(), I::kTheHoleValueRootIndex))
+    return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>::New(GetIsolate(), reinterpret_cast<Value*>(value_));
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(S* whatever) {
+  // Uncompilable to prevent inadvertent misuse.
+  TYPE_CHECK(S*, Primitive);
+}
+
+template<typename T>
+internal::Object* ReturnValue<T>::GetDefaultValue() {
+  // Default value is always the pointer below value_ on the stack.
+  return value_[-1];
+}
+
+template <typename T>
+FunctionCallbackInfo<T>::FunctionCallbackInfo(internal::Object** implicit_args,
+                                              internal::Object** values,
+                                              int length)
+    : implicit_args_(implicit_args), values_(values), length_(length) {}
+
+template<typename T>
+Local<Value> FunctionCallbackInfo<T>::operator[](int i) const {
+  if (i < 0 || length_ <= i) return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>(reinterpret_cast<Value*>(values_ - i));
+}
+
+
+template<typename T>
+Local<Function> FunctionCallbackInfo<T>::Callee() const {
+  return Local<Function>(reinterpret_cast<Function*>(
+      &implicit_args_[kCalleeIndex]));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(
+      &implicit_args_[kHolderIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::NewTarget() const {
+  return Local<Value>(
+      reinterpret_cast<Value*>(&implicit_args_[kNewTargetIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&implicit_args_[kDataIndex]));
+}
+
+
+template<typename T>
+Isolate* FunctionCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&implicit_args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+ReturnValue<T> FunctionCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&implicit_args_[kReturnValueIndex]);
+}
+
+
+template<typename T>
+bool FunctionCallbackInfo<T>::IsConstructCall() const {
+  return !NewTarget()->IsUndefined();
+}
+
+
+template<typename T>
+int FunctionCallbackInfo<T>::Length() const {
+  return length_;
+}
+
+ScriptOrigin::ScriptOrigin(Local<Value> resource_name,
+                           Local<Integer> resource_line_offset,
+                           Local<Integer> resource_column_offset,
+                           Local<Boolean> resource_is_shared_cross_origin,
+                           Local<Integer> script_id,
+                           Local<Value> source_map_url,
+                           Local<Boolean> resource_is_opaque,
+                           Local<Boolean> is_wasm, Local<Boolean> is_module)
+    : resource_name_(resource_name),
+      resource_line_offset_(resource_line_offset),
+      resource_column_offset_(resource_column_offset),
+      options_(!resource_is_shared_cross_origin.IsEmpty() &&
+                   resource_is_shared_cross_origin->IsTrue(),
+               !resource_is_opaque.IsEmpty() && resource_is_opaque->IsTrue(),
+               !is_wasm.IsEmpty() && is_wasm->IsTrue(),
+               !is_module.IsEmpty() && is_module->IsTrue()),
+      script_id_(script_id),
+      source_map_url_(source_map_url) {}
+
+Local<Value> ScriptOrigin::ResourceName() const { return resource_name_; }
+
+
+Local<Integer> ScriptOrigin::ResourceLineOffset() const {
+  return resource_line_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ResourceColumnOffset() const {
+  return resource_column_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ScriptID() const { return script_id_; }
+
+
+Local<Value> ScriptOrigin::SourceMapUrl() const { return source_map_url_; }
+
+
+ScriptCompiler::Source::Source(Local<String> string, const ScriptOrigin& origin,
+                               CachedData* data)
+    : source_string(string),
+      resource_name(origin.ResourceName()),
+      resource_line_offset(origin.ResourceLineOffset()),
+      resource_column_offset(origin.ResourceColumnOffset()),
+      resource_options(origin.Options()),
+      source_map_url(origin.SourceMapUrl()),
+      cached_data(data) {}
+
+
+ScriptCompiler::Source::Source(Local<String> string,
+                               CachedData* data)
+    : source_string(string), cached_data(data) {}
+
+
+ScriptCompiler::Source::~Source() {
+  delete cached_data;
+}
+
+
+const ScriptCompiler::CachedData* ScriptCompiler::Source::GetCachedData()
+    const {
+  return cached_data;
+}
+
+const ScriptOriginOptions& ScriptCompiler::Source::GetResourceOptions() const {
+  return resource_options;
+}
+
+Local<Boolean> Boolean::New(Isolate* isolate, bool value) {
+  return value ? True(isolate) : False(isolate);
+}
+
+void Template::Set(Isolate* isolate, const char* name, Local<Data> value) {
+  Set(String::NewFromUtf8(isolate, name, NewStringType::kInternalized)
+          .ToLocalChecked(),
+      value);
+}
+
+
+Local<Value> Object::GetInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (instance_type == I::kJSObjectType ||
+      instance_type == I::kJSApiObjectType) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    O* value = I::ReadField<O*>(obj, offset);
+    O** result = HandleScope::CreateHandle(reinterpret_cast<HO*>(obj), value);
+    return Local<Value>(reinterpret_cast<Value*>(result));
+  }
+#endif
+  return SlowGetInternalField(index);
+}
+
+
+void* Object::GetAlignedPointerFromInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (V8_LIKELY(instance_type == I::kJSObjectType ||
+                instance_type == I::kJSApiObjectType)) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<void*>(obj, offset);
+  }
+#endif
+  return SlowGetAlignedPointerFromInternalField(index);
+}
+
+String* String::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<String*>(value);
+}
+
+
+Local<String> String::Empty(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kEmptyStringRootIndex);
+  return Local<String>(reinterpret_cast<String*>(slot));
+}
+
+
+String::ExternalStringResource* String::GetExternalStringResource() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  String::ExternalStringResource* result;
+  if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    result = reinterpret_cast<String::ExternalStringResource*>(value);
+  } else {
+    result = NULL;
+  }
+#ifdef V8_ENABLE_CHECKS
+  VerifyExternalStringResource(result);
+#endif
+  return result;
+}
+
+
+String::ExternalStringResourceBase* String::GetExternalStringResourceBase(
+    String::Encoding* encoding_out) const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  int type = I::GetInstanceType(obj) & I::kFullStringRepresentationMask;
+  *encoding_out = static_cast<Encoding>(type & I::kStringEncodingMask);
+  ExternalStringResourceBase* resource = NULL;
+  if (type == I::kExternalOneByteRepresentationTag ||
+      type == I::kExternalTwoByteRepresentationTag) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    resource = static_cast<ExternalStringResourceBase*>(value);
+  }
+#ifdef V8_ENABLE_CHECKS
+    VerifyExternalStringResourceBase(resource, *encoding_out);
+#endif
+  return resource;
+}
+
+
+bool Value::IsUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsUndefined();
+#else
+  return QuickIsUndefined();
+#endif
+}
+
+bool Value::QuickIsUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kUndefinedOddballKind);
+}
+
+
+bool Value::IsNull() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull();
+#else
+  return QuickIsNull();
+#endif
+}
+
+bool Value::QuickIsNull() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kNullOddballKind);
+}
+
+bool Value::IsNullOrUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull() || FullIsUndefined();
+#else
+  return QuickIsNullOrUndefined();
+#endif
+}
+
+bool Value::QuickIsNullOrUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  int kind = I::GetOddballKind(obj);
+  return kind == I::kNullOddballKind || kind == I::kUndefinedOddballKind;
+}
+
+bool Value::IsString() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsString();
+#else
+  return QuickIsString();
+#endif
+}
+
+bool Value::QuickIsString() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  return (I::GetInstanceType(obj) < I::kFirstNonstringType);
+}
+
+
+template <class T> Value* Value::Cast(T* value) {
+  return static_cast<Value*>(value);
+}
+
+
+Local<Boolean> Value::ToBoolean() const {
+  return ToBoolean(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Boolean>());
+}
+
+
+Local<Number> Value::ToNumber() const {
+  return ToNumber(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Number>());
+}
+
+
+Local<String> Value::ToString() const {
+  return ToString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<String> Value::ToDetailString() const {
+  return ToDetailString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<Object> Value::ToObject() const {
+  return ToObject(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Object>());
+}
+
+
+Local<Integer> Value::ToInteger() const {
+  return ToInteger(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Integer>());
+}
+
+
+Local<Uint32> Value::ToUint32() const {
+  return ToUint32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Uint32>());
+}
+
+
+Local<Int32> Value::ToInt32() const {
+  return ToInt32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Int32>());
+}
+
+
+Boolean* Boolean::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Boolean*>(value);
+}
+
+
+Name* Name::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Name*>(value);
+}
+
+
+Symbol* Symbol::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Symbol*>(value);
+}
+
+
+Number* Number::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Number*>(value);
+}
+
+
+Integer* Integer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Integer*>(value);
+}
+
+
+Int32* Int32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32*>(value);
+}
+
+
+Uint32* Uint32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32*>(value);
+}
+
+
+Date* Date::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Date*>(value);
+}
+
+
+StringObject* StringObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<StringObject*>(value);
+}
+
+
+SymbolObject* SymbolObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SymbolObject*>(value);
+}
+
+
+NumberObject* NumberObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<NumberObject*>(value);
+}
+
+
+BooleanObject* BooleanObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<BooleanObject*>(value);
+}
+
+
+RegExp* RegExp::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<RegExp*>(value);
+}
+
+
+Object* Object::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Object*>(value);
+}
+
+
+Array* Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Array*>(value);
+}
+
+
+Map* Map::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Map*>(value);
+}
+
+
+Set* Set::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Set*>(value);
+}
+
+
+Promise* Promise::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise*>(value);
+}
+
+
+Proxy* Proxy::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Proxy*>(value);
+}
+
+WasmCompiledModule* WasmCompiledModule::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<WasmCompiledModule*>(value);
+}
+
+Promise::Resolver* Promise::Resolver::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise::Resolver*>(value);
+}
+
+
+ArrayBuffer* ArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBuffer*>(value);
+}
+
+
+ArrayBufferView* ArrayBufferView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBufferView*>(value);
+}
+
+
+TypedArray* TypedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<TypedArray*>(value);
+}
+
+
+Uint8Array* Uint8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8Array*>(value);
+}
+
+
+Int8Array* Int8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int8Array*>(value);
+}
+
+
+Uint16Array* Uint16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint16Array*>(value);
+}
+
+
+Int16Array* Int16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int16Array*>(value);
+}
+
+
+Uint32Array* Uint32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32Array*>(value);
+}
+
+
+Int32Array* Int32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32Array*>(value);
+}
+
+
+Float32Array* Float32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float32Array*>(value);
+}
+
+
+Float64Array* Float64Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float64Array*>(value);
+}
+
+
+Uint8ClampedArray* Uint8ClampedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8ClampedArray*>(value);
+}
+
+
+DataView* DataView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<DataView*>(value);
+}
+
+
+SharedArrayBuffer* SharedArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedArrayBuffer*>(value);
+}
+
+
+Function* Function::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Function*>(value);
+}
+
+
+External* External::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<External*>(value);
+}
+
+
+template<typename T>
+Isolate* PropertyCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+Local<Value> PropertyCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&args_[kDataIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kThisIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kHolderIndex]));
+}
+
+
+template<typename T>
+ReturnValue<T> PropertyCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&args_[kReturnValueIndex]);
+}
+
+template <typename T>
+bool PropertyCallbackInfo<T>::ShouldThrowOnError() const {
+  typedef internal::Internals I;
+  return args_[kShouldThrowOnErrorIndex] != I::IntToSmi(0);
+}
+
+
+Local<Primitive> Undefined(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kUndefinedValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Primitive> Null(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kNullValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Boolean> True(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kTrueValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+Local<Boolean> False(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kFalseValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+void Isolate::SetData(uint32_t slot, void* data) {
+  typedef internal::Internals I;
+  I::SetEmbedderData(this, slot, data);
+}
+
+
+void* Isolate::GetData(uint32_t slot) {
+  typedef internal::Internals I;
+  return I::GetEmbedderData(this, slot);
+}
+
+
+uint32_t Isolate::GetNumberOfDataSlots() {
+  typedef internal::Internals I;
+  return I::kNumIsolateDataSlots;
+}
+
+
+int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
+    int64_t change_in_bytes) {
+  typedef internal::Internals I;
+  int64_t* external_memory = reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryOffset);
+  const int64_t external_memory_limit = *reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryLimitOffset);
+  const int64_t amount = *external_memory + change_in_bytes;
+  *external_memory = amount;
+  if (change_in_bytes > 0 && amount > external_memory_limit) {
+    ReportExternalAllocationLimitReached();
+  }
+  return *external_memory;
+}
+
+Local<Value> Context::GetEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  HO* context = *reinterpret_cast<HO**>(this);
+  O** result =
+      HandleScope::CreateHandle(context, I::ReadEmbedderData<O*>(this, index));
+  return Local<Value>(reinterpret_cast<Value*>(result));
+#else
+  return SlowGetEmbedderData(index);
+#endif
+}
+
+
+void* Context::GetAlignedPointerFromEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Internals I;
+  return I::ReadEmbedderData<void*>(this, index);
+#else
+  return SlowGetAlignedPointerFromEmbedderData(index);
+#endif
+}
+
+
+void V8::SetAllowCodeGenerationFromStringsCallback(
+    AllowCodeGenerationFromStringsCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetAllowCodeGenerationFromStringsCallback(callback);
+}
+
+
+bool V8::IsDead() {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->IsDead();
+}
+
+
+bool V8::AddMessageListener(MessageCallback that, Local<Value> data) {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->AddMessageListener(that, data);
+}
+
+
+void V8::RemoveMessageListeners(MessageCallback that) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveMessageListeners(that);
+}
+
+
+void V8::SetFailedAccessCheckCallbackFunction(
+    FailedAccessCheckCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFailedAccessCheckCallbackFunction(callback);
+}
+
+
+void V8::SetCaptureStackTraceForUncaughtExceptions(
+    bool capture, int frame_limit, StackTrace::StackTraceOptions options) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetCaptureStackTraceForUncaughtExceptions(capture, frame_limit,
+                                                     options);
+}
+
+
+void V8::SetFatalErrorHandler(FatalErrorCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFatalErrorHandler(callback);
+}
+
+void V8::RemoveGCPrologueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCPrologueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+
+void V8::RemoveGCEpilogueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCEpilogueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+void V8::TerminateExecution(Isolate* isolate) { isolate->TerminateExecution(); }
+
+
+bool V8::IsExecutionTerminating(Isolate* isolate) {
+  if (isolate == NULL) {
+    isolate = Isolate::GetCurrent();
+  }
+  return isolate->IsExecutionTerminating();
+}
+
+
+void V8::CancelTerminateExecution(Isolate* isolate) {
+  isolate->CancelTerminateExecution();
+}
+
+
+void V8::VisitExternalResources(ExternalResourceVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitExternalResources(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(PersistentHandleVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(Isolate* isolate,
+                                  PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesForPartialDependence(Isolate* isolate,
+                                          PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesForPartialDependence(visitor);
+}
+
+/**
+ * \example shell.cc
+ * A simple shell that takes a list of expressions on the
+ * command-line and executes them.
+ */
+
+
+/**
+ * \example process.cc
+ */
+
+
+}  // namespace v8
+
+
+#undef TYPE_CHECK
+
+
+#endif  // INCLUDE_V8_H_
diff --git a/android/arm64-v8a/include/v8/v8config.h b/android/arm64-v8a/include/v8/v8config.h
new file mode 100644
index 00000000..964949c2
--- /dev/null
+++ b/android/arm64-v8a/include/v8/v8config.h
@@ -0,0 +1,428 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8CONFIG_H_
+#define V8CONFIG_H_
+
+// clang-format off
+
+// Platform headers for feature detection below.
+#if defined(__ANDROID__)
+# include <sys/cdefs.h>
+#elif defined(__APPLE__)
+# include <TargetConditionals.h>
+#elif defined(__linux__)
+# include <features.h>
+#endif
+
+
+// This macro allows to test for the version of the GNU C library (or
+// a compatible C library that masquerades as glibc). It evaluates to
+// 0 if libc is not GNU libc or compatible.
+// Use like:
+//  #if V8_GLIBC_PREREQ(2, 3)
+//   ...
+//  #endif
+#if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
+# define V8_GLIBC_PREREQ(major, minor)                                    \
+    ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
+#else
+# define V8_GLIBC_PREREQ(major, minor) 0
+#endif
+
+
+// This macro allows to test for the version of the GNU C++ compiler.
+// Note that this also applies to compilers that masquerade as GCC,
+// for example clang and the Intel C++ compiler for Linux.
+// Use like:
+//  #if V8_GNUC_PREREQ(4, 3, 1)
+//   ...
+//  #endif
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)                         \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >=   \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)      \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >=      \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#else
+# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
+#endif
+
+
+
+// -----------------------------------------------------------------------------
+// Operating system detection
+//
+//  V8_OS_ANDROID       - Android
+//  V8_OS_BSD           - BSDish (Mac OS X, Net/Free/Open/DragonFlyBSD)
+//  V8_OS_CYGWIN        - Cygwin
+//  V8_OS_DRAGONFLYBSD  - DragonFlyBSD
+//  V8_OS_FREEBSD       - FreeBSD
+//  V8_OS_LINUX         - Linux
+//  V8_OS_MACOSX        - Mac OS X
+//  V8_OS_NETBSD        - NetBSD
+//  V8_OS_OPENBSD       - OpenBSD
+//  V8_OS_POSIX         - POSIX compatible (mostly everything except Windows)
+//  V8_OS_QNX           - QNX Neutrino
+//  V8_OS_SOLARIS       - Sun Solaris and OpenSolaris
+//  V8_OS_AIX           - AIX
+//  V8_OS_WIN           - Microsoft Windows
+
+#if defined(__ANDROID__)
+# define V8_OS_ANDROID 1
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__APPLE__)
+# define V8_OS_BSD 1
+# define V8_OS_MACOSX 1
+# define V8_OS_POSIX 1
+#elif defined(__CYGWIN__)
+# define V8_OS_CYGWIN 1
+# define V8_OS_POSIX 1
+#elif defined(__linux__)
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__sun)
+# define V8_OS_POSIX 1
+# define V8_OS_SOLARIS 1
+#elif defined(_AIX)
+#define V8_OS_POSIX 1
+#define V8_OS_AIX 1
+#elif defined(__FreeBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_FREEBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__DragonFly__)
+# define V8_OS_BSD 1
+# define V8_OS_DRAGONFLYBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__NetBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_NETBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__OpenBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_OPENBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__QNXNTO__)
+# define V8_OS_POSIX 1
+# define V8_OS_QNX 1
+#elif defined(_WIN32)
+# define V8_OS_WIN 1
+#endif
+
+
+// -----------------------------------------------------------------------------
+// C library detection
+//
+//  V8_LIBC_MSVCRT  - MSVC libc
+//  V8_LIBC_BIONIC  - Bionic libc
+//  V8_LIBC_BSD     - BSD libc derivate
+//  V8_LIBC_GLIBC   - GNU C library
+//  V8_LIBC_UCLIBC  - uClibc
+//
+// Note that testing for libc must be done using #if not #ifdef. For example,
+// to test for the GNU C library, use:
+//  #if V8_LIBC_GLIBC
+//   ...
+//  #endif
+
+#if defined (_MSC_VER)
+# define V8_LIBC_MSVCRT 1
+#elif defined(__BIONIC__)
+# define V8_LIBC_BIONIC 1
+# define V8_LIBC_BSD 1
+#elif defined(__UCLIBC__)
+// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
+# define V8_LIBC_UCLIBC 1
+#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
+# define V8_LIBC_GLIBC 1
+#else
+# define V8_LIBC_BSD V8_OS_BSD
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Compiler detection
+//
+//  V8_CC_GNU     - GCC, or clang in gcc mode
+//  V8_CC_INTEL   - Intel C++
+//  V8_CC_MINGW   - Minimalist GNU for Windows
+//  V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
+//  V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
+//  V8_CC_MSVC    - Microsoft Visual C/C++, or clang in cl.exe mode
+//
+// C++11 feature detection
+//
+//  V8_HAS_CXX11_ALIGNAS        - alignas specifier supported
+//  V8_HAS_CXX11_ALIGNOF        - alignof(type) operator supported
+//
+// Compiler-specific feature detection
+//
+//  V8_HAS___ALIGNOF                    - __alignof(type) operator supported
+//  V8_HAS___ALIGNOF__                  - __alignof__(type) operator supported
+//  V8_HAS_ATTRIBUTE_ALIGNED            - __attribute__((aligned(n))) supported
+//  V8_HAS_ATTRIBUTE_ALWAYS_INLINE      - __attribute__((always_inline))
+//                                        supported
+//  V8_HAS_ATTRIBUTE_DEPRECATED         - __attribute__((deprecated)) supported
+//  V8_HAS_ATTRIBUTE_NOINLINE           - __attribute__((noinline)) supported
+//  V8_HAS_ATTRIBUTE_NORETURN           - __attribute__((noreturn)) supported
+//  V8_HAS_ATTRIBUTE_UNUSED             - __attribute__((unused)) supported
+//  V8_HAS_ATTRIBUTE_VISIBILITY         - __attribute__((visibility)) supported
+//  V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
+//                                        supported
+//  V8_HAS_BUILTIN_CLZ                  - __builtin_clz() supported
+//  V8_HAS_BUILTIN_CTZ                  - __builtin_ctz() supported
+//  V8_HAS_BUILTIN_EXPECT               - __builtin_expect() supported
+//  V8_HAS_BUILTIN_FRAME_ADDRESS        - __builtin_frame_address() supported
+//  V8_HAS_BUILTIN_POPCOUNT             - __builtin_popcount() supported
+//  V8_HAS_BUILTIN_SADD_OVERFLOW        - __builtin_sadd_overflow() supported
+//  V8_HAS_BUILTIN_SSUB_OVERFLOW        - __builtin_ssub_overflow() supported
+//  V8_HAS_BUILTIN_UADD_OVERFLOW        - __builtin_uadd_overflow() supported
+//  V8_HAS_DECLSPEC_ALIGN               - __declspec(align(n)) supported
+//  V8_HAS_DECLSPEC_DEPRECATED          - __declspec(deprecated) supported
+//  V8_HAS_DECLSPEC_NOINLINE            - __declspec(noinline) supported
+//  V8_HAS_DECLSPEC_SELECTANY           - __declspec(selectany) supported
+//  V8_HAS_DECLSPEC_NORETURN            - __declspec(noreturn) supported
+//  V8_HAS___FORCEINLINE                - __forceinline supported
+//
+// Note that testing for compilers and/or features must be done using #if
+// not #ifdef. For example, to test for Intel C++ Compiler, use:
+//  #if V8_CC_INTEL
+//   ...
+//  #endif
+
+#if defined(__clang__)
+
+#if defined(__GNUC__)  // Clang in gcc mode.
+# define V8_CC_GNU 1
+#endif
+
+// Clang defines __alignof__ as alias for __alignof
+# define V8_HAS___ALIGNOF 1
+# define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
+# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
+# define V8_HAS_ATTRIBUTE_NORETURN (__has_attribute(noreturn))
+# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (__has_attribute(warn_unused_result))
+
+# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
+# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
+# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
+# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
+# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
+# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
+# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
+
+# define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
+
+#elif defined(__GNUC__)
+
+# define V8_CC_GNU 1
+# if defined(__INTEL_COMPILER)  // Intel C++ also masquerades as GCC 3.2.0
+#  define V8_CC_INTEL 1
+# endif
+# if defined(__MINGW32__)
+#  define V8_CC_MINGW32 1
+# endif
+# if defined(__MINGW64__)
+#  define V8_CC_MINGW64 1
+# endif
+# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
+
+# define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
+// always_inline is available in gcc 4.0 but not very reliable until 4.4.
+// Works around "sorry, unimplemented: inlining failed" build errors with
+// older compilers.
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (V8_GNUC_PREREQ(4, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
+# define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_NORETURN (V8_GNUC_PREREQ(2, 5, 0))
+# define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
+
+# define V8_HAS_BUILTIN_CLZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_CTZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
+
+# if __cplusplus >= 201103L
+#  define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
+#  define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
+# endif
+#endif
+
+#if defined(_MSC_VER)
+# define V8_CC_MSVC 1
+# define V8_HAS___ALIGNOF 1
+
+# define V8_HAS_DECLSPEC_ALIGN 1
+# define V8_HAS_DECLSPEC_DEPRECATED 1
+# define V8_HAS_DECLSPEC_NOINLINE 1
+# define V8_HAS_DECLSPEC_SELECTANY 1
+# define V8_HAS_DECLSPEC_NORETURN 1
+
+# define V8_HAS___FORCEINLINE 1
+
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Helper macros
+
+// A macro used to make better inlining. Don't bother for debug builds.
+// Use like:
+//   V8_INLINE int GetZero() { return 0; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
+# define V8_INLINE inline __attribute__((always_inline))
+#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
+# define V8_INLINE __forceinline
+#else
+# define V8_INLINE inline
+#endif
+
+
+// A macro used to tell the compiler to never inline a particular function.
+// Don't bother for debug builds.
+// Use like:
+//   V8_NOINLINE int GetMinusOne() { return -1; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
+# define V8_NOINLINE __attribute__((noinline))
+#elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
+# define V8_NOINLINE __declspec(noinline)
+#else
+# define V8_NOINLINE /* NOT SUPPORTED */
+#endif
+
+
+// A macro used to tell the compiler that a particular function never returns.
+// Use like:
+//   V8_NORETURN void MyAbort() { abort(); }
+#if V8_HAS_ATTRIBUTE_NORETURN
+# define V8_NORETURN __attribute__((noreturn))
+#elif V8_HAS_DECLSPEC_NORETURN
+# define V8_NORETURN __declspec(noreturn)
+#else
+# define V8_NORETURN /* NOT SUPPORTED */
+#endif
+
+
+// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
+#if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATED(message, declarator) declarator
+#endif
+
+
+// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
+#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) && \
+    V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATE_SOON(message, declarator) declarator
+#endif
+
+
+// A macro to provide the compiler with branch prediction information.
+#if V8_HAS_BUILTIN_EXPECT
+# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
+# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
+#else
+# define V8_UNLIKELY(condition) (condition)
+# define V8_LIKELY(condition) (condition)
+#endif
+
+
+// This macro allows to specify memory alignment for structs, classes, etc.
+// Use like:
+//   class V8_ALIGNED(16) MyClass { ... };
+//   V8_ALIGNED(32) int array[42];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNED(n) alignas(n)
+#elif V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNED(n) __attribute__((aligned(n)))
+#elif V8_HAS_DECLSPEC_ALIGN
+# define V8_ALIGNED(n) __declspec(align(n))
+#else
+# define V8_ALIGNED(n) /* NOT SUPPORTED */
+#endif
+
+
+// This macro is similar to V8_ALIGNED(), but takes a type instead of size
+// in bytes. If the compiler does not supports using the alignment of the
+// |type|, it will align according to the |alignment| instead. For example,
+// Visual Studio C++ cannot combine __declspec(align) and __alignof. The
+// |alignment| must be a literal that is used as a kind of worst-case fallback
+// alignment.
+// Use like:
+//   struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
+//   V8_ALIGNAS(double, 8) int array[100];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNAS(type, alignment) alignas(type)
+#elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
+#else
+# define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
+#endif
+
+
+// This macro returns alignment in bytes (an integer power of two) required for
+// any instance of the given type, which is either complete type, an array type,
+// or a reference type.
+// Use like:
+//   size_t alignment = V8_ALIGNOF(double);
+#if V8_HAS_CXX11_ALIGNOF
+# define V8_ALIGNOF(type) alignof(type)
+#elif V8_HAS___ALIGNOF
+# define V8_ALIGNOF(type) __alignof(type)
+#elif V8_HAS___ALIGNOF__
+# define V8_ALIGNOF(type) __alignof__(type)
+#else
+// Note that alignment of a type within a struct can be less than the
+// alignment of the type stand-alone (because of ancient ABIs), so this
+// should only be used as a last resort.
+namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
+# define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
+#endif
+
+// Annotate a function indicating the caller must examine the return value.
+// Use like:
+//   int foo() WARN_UNUSED_RESULT;
+#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
+#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
+#endif
+
+// clang-format on
+
+#endif  // V8CONFIG_H_
diff --git a/android/arm64-v8a/libinspector.a b/android/arm64-v8a/libinspector.a
new file mode 100644
index 00000000..1ad278dc
Binary files /dev/null and b/android/arm64-v8a/libinspector.a differ
diff --git a/android/arm64-v8a/libv8_base.a b/android/arm64-v8a/libv8_base.a
new file mode 100644
index 00000000..aec3cb5a
Binary files /dev/null and b/android/arm64-v8a/libv8_base.a differ
diff --git a/android/arm64-v8a/libv8_builtins_generators.a b/android/arm64-v8a/libv8_builtins_generators.a
new file mode 100644
index 00000000..884b81a2
Binary files /dev/null and b/android/arm64-v8a/libv8_builtins_generators.a differ
diff --git a/android/arm64-v8a/libv8_builtins_setup.a b/android/arm64-v8a/libv8_builtins_setup.a
new file mode 100644
index 00000000..456cf030
Binary files /dev/null and b/android/arm64-v8a/libv8_builtins_setup.a differ
diff --git a/android/arm64-v8a/libv8_libbase.a b/android/arm64-v8a/libv8_libbase.a
new file mode 100644
index 00000000..e40c72b8
Binary files /dev/null and b/android/arm64-v8a/libv8_libbase.a differ
diff --git a/android/arm64-v8a/libv8_libplatform.a b/android/arm64-v8a/libv8_libplatform.a
new file mode 100644
index 00000000..62fe2982
Binary files /dev/null and b/android/arm64-v8a/libv8_libplatform.a differ
diff --git a/android/arm64-v8a/libv8_libsampler.a b/android/arm64-v8a/libv8_libsampler.a
new file mode 100644
index 00000000..804c4510
Binary files /dev/null and b/android/arm64-v8a/libv8_libsampler.a differ
diff --git a/android/arm64-v8a/libv8_nosnapshot.a b/android/arm64-v8a/libv8_nosnapshot.a
new file mode 100644
index 00000000..029260fd
Binary files /dev/null and b/android/arm64-v8a/libv8_nosnapshot.a differ
diff --git a/android/armeabi-v7a/include/v8/libplatform/libplatform-export.h b/android/armeabi-v7a/include/v8/libplatform/libplatform-export.h
new file mode 100644
index 00000000..15618434
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/libplatform/libplatform-export.h
@@ -0,0 +1,29 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+
+#if defined(_WIN32)
+
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllexport)
+#elif USING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllimport)
+#else
+#define V8_PLATFORM_EXPORT
+#endif  // BUILDING_V8_PLATFORM_SHARED
+
+#else  // defined(_WIN32)
+
+// Setup for Linux shared library export.
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __attribute__((visibility("default")))
+#else
+#define V8_PLATFORM_EXPORT
+#endif
+
+#endif  // defined(_WIN32)
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
diff --git a/android/armeabi-v7a/include/v8/libplatform/libplatform.h b/android/armeabi-v7a/include/v8/libplatform/libplatform.h
new file mode 100644
index 00000000..e9450456
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/libplatform/libplatform.h
@@ -0,0 +1,78 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_H_
+
+#include "libplatform/libplatform-export.h"
+#include "libplatform/v8-tracing.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+namespace platform {
+
+enum class IdleTaskSupport { kDisabled, kEnabled };
+enum class InProcessStackDumping { kDisabled, kEnabled };
+
+enum class MessageLoopBehavior : bool {
+  kDoNotWait = false,
+  kWaitForWork = true
+};
+
+/**
+ * Returns a new instance of the default v8::Platform implementation.
+ *
+ * The caller will take ownership of the returned pointer. |thread_pool_size|
+ * is the number of worker threads to allocate for background jobs. If a value
+ * of zero is passed, a suitable default based on the current number of
+ * processors online will be chosen.
+ * If |idle_task_support| is enabled then the platform will accept idle
+ * tasks (IdleTasksEnabled will return true) and will rely on the embedder
+ * calling v8::platform::RunIdleTasks to process the idle tasks.
+ */
+V8_PLATFORM_EXPORT v8::Platform* CreateDefaultPlatform(
+    int thread_pool_size = 0,
+    IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
+    InProcessStackDumping in_process_stack_dumping =
+        InProcessStackDumping::kEnabled);
+
+/**
+ * Pumps the message loop for the given isolate.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * Returns true if a task was executed, and false otherwise. Unless requested
+ * through the |behavior| parameter, this call does not block if no task is
+ * pending. The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT bool PumpMessageLoop(
+    v8::Platform* platform, v8::Isolate* isolate,
+    MessageLoopBehavior behavior = MessageLoopBehavior::kDoNotWait);
+
+V8_PLATFORM_EXPORT void EnsureEventLoopInitialized(v8::Platform* platform,
+                                                   v8::Isolate* isolate);
+
+/**
+ * Runs pending idle tasks for at most |idle_time_in_seconds| seconds.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * This call does not block if no task is pending. The |platform| has to be
+ * created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void RunIdleTasks(v8::Platform* platform,
+                                     v8::Isolate* isolate,
+                                     double idle_time_in_seconds);
+
+/**
+ * Attempts to set the tracing controller for the given platform.
+ *
+ * The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void SetTracingController(
+    v8::Platform* platform,
+    v8::platform::tracing::TracingController* tracing_controller);
+
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_H_
diff --git a/android/armeabi-v7a/include/v8/libplatform/v8-tracing.h b/android/armeabi-v7a/include/v8/libplatform/v8-tracing.h
new file mode 100644
index 00000000..902f8ea9
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/libplatform/v8-tracing.h
@@ -0,0 +1,270 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_V8_TRACING_H_
+#define V8_LIBPLATFORM_V8_TRACING_H_
+
+#include <fstream>
+#include <memory>
+#include <unordered_set>
+#include <vector>
+
+#include "libplatform/libplatform-export.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+
+namespace base {
+class Mutex;
+}  // namespace base
+
+namespace platform {
+namespace tracing {
+
+const int kTraceMaxNumArgs = 2;
+
+class V8_PLATFORM_EXPORT TraceObject {
+ public:
+  union ArgValue {
+    bool as_bool;
+    uint64_t as_uint;
+    int64_t as_int;
+    double as_double;
+    const void* as_pointer;
+    const char* as_string;
+  };
+
+  TraceObject() {}
+  ~TraceObject();
+  void Initialize(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateDuration();
+  void InitializeForTesting(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags, int pid, int tid, int64_t ts, int64_t tts,
+      uint64_t duration, uint64_t cpu_duration);
+
+  int pid() const { return pid_; }
+  int tid() const { return tid_; }
+  char phase() const { return phase_; }
+  const uint8_t* category_enabled_flag() const {
+    return category_enabled_flag_;
+  }
+  const char* name() const { return name_; }
+  const char* scope() const { return scope_; }
+  uint64_t id() const { return id_; }
+  uint64_t bind_id() const { return bind_id_; }
+  int num_args() const { return num_args_; }
+  const char** arg_names() { return arg_names_; }
+  uint8_t* arg_types() { return arg_types_; }
+  ArgValue* arg_values() { return arg_values_; }
+  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables() {
+    return arg_convertables_;
+  }
+  unsigned int flags() const { return flags_; }
+  int64_t ts() { return ts_; }
+  int64_t tts() { return tts_; }
+  uint64_t duration() { return duration_; }
+  uint64_t cpu_duration() { return cpu_duration_; }
+
+ private:
+  int pid_;
+  int tid_;
+  char phase_;
+  const char* name_;
+  const char* scope_;
+  const uint8_t* category_enabled_flag_;
+  uint64_t id_;
+  uint64_t bind_id_;
+  int num_args_ = 0;
+  const char* arg_names_[kTraceMaxNumArgs];
+  uint8_t arg_types_[kTraceMaxNumArgs];
+  ArgValue arg_values_[kTraceMaxNumArgs];
+  std::unique_ptr<v8::ConvertableToTraceFormat>
+      arg_convertables_[kTraceMaxNumArgs];
+  char* parameter_copy_storage_ = nullptr;
+  unsigned int flags_;
+  int64_t ts_;
+  int64_t tts_;
+  uint64_t duration_;
+  uint64_t cpu_duration_;
+
+  // Disallow copy and assign
+  TraceObject(const TraceObject&) = delete;
+  void operator=(const TraceObject&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceWriter {
+ public:
+  TraceWriter() {}
+  virtual ~TraceWriter() {}
+  virtual void AppendTraceEvent(TraceObject* trace_event) = 0;
+  virtual void Flush() = 0;
+
+  static TraceWriter* CreateJSONTraceWriter(std::ostream& stream);
+
+ private:
+  // Disallow copy and assign
+  TraceWriter(const TraceWriter&) = delete;
+  void operator=(const TraceWriter&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBufferChunk {
+ public:
+  explicit TraceBufferChunk(uint32_t seq);
+
+  void Reset(uint32_t new_seq);
+  bool IsFull() const { return next_free_ == kChunkSize; }
+  TraceObject* AddTraceEvent(size_t* event_index);
+  TraceObject* GetEventAt(size_t index) { return &chunk_[index]; }
+
+  uint32_t seq() const { return seq_; }
+  size_t size() const { return next_free_; }
+
+  static const size_t kChunkSize = 64;
+
+ private:
+  size_t next_free_ = 0;
+  TraceObject chunk_[kChunkSize];
+  uint32_t seq_;
+
+  // Disallow copy and assign
+  TraceBufferChunk(const TraceBufferChunk&) = delete;
+  void operator=(const TraceBufferChunk&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBuffer {
+ public:
+  TraceBuffer() {}
+  virtual ~TraceBuffer() {}
+
+  virtual TraceObject* AddTraceEvent(uint64_t* handle) = 0;
+  virtual TraceObject* GetEventByHandle(uint64_t handle) = 0;
+  virtual bool Flush() = 0;
+
+  static const size_t kRingBufferChunks = 1024;
+
+  static TraceBuffer* CreateTraceBufferRingBuffer(size_t max_chunks,
+                                                  TraceWriter* trace_writer);
+
+ private:
+  // Disallow copy and assign
+  TraceBuffer(const TraceBuffer&) = delete;
+  void operator=(const TraceBuffer&) = delete;
+};
+
+// Options determines how the trace buffer stores data.
+enum TraceRecordMode {
+  // Record until the trace buffer is full.
+  RECORD_UNTIL_FULL,
+
+  // Record until the user ends the trace. The trace buffer is a fixed size
+  // and we use it as a ring buffer during recording.
+  RECORD_CONTINUOUSLY,
+
+  // Record until the trace buffer is full, but with a huge buffer size.
+  RECORD_AS_MUCH_AS_POSSIBLE,
+
+  // Echo to console. Events are discarded.
+  ECHO_TO_CONSOLE,
+};
+
+class V8_PLATFORM_EXPORT TraceConfig {
+ public:
+  typedef std::vector<std::string> StringList;
+
+  static TraceConfig* CreateDefaultTraceConfig();
+
+  TraceConfig() : enable_systrace_(false), enable_argument_filter_(false) {}
+  TraceRecordMode GetTraceRecordMode() const { return record_mode_; }
+  bool IsSystraceEnabled() const { return enable_systrace_; }
+  bool IsArgumentFilterEnabled() const { return enable_argument_filter_; }
+
+  void SetTraceRecordMode(TraceRecordMode mode) { record_mode_ = mode; }
+  void EnableSystrace() { enable_systrace_ = true; }
+  void EnableArgumentFilter() { enable_argument_filter_ = true; }
+
+  void AddIncludedCategory(const char* included_category);
+
+  bool IsCategoryGroupEnabled(const char* category_group) const;
+
+ private:
+  TraceRecordMode record_mode_;
+  bool enable_systrace_ : 1;
+  bool enable_argument_filter_ : 1;
+  StringList included_categories_;
+
+  // Disallow copy and assign
+  TraceConfig(const TraceConfig&) = delete;
+  void operator=(const TraceConfig&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TracingController {
+ public:
+  enum Mode { DISABLED = 0, RECORDING_MODE };
+
+  // The pointer returned from GetCategoryGroupEnabledInternal() points to a
+  // value with zero or more of the following bits. Used in this class only.
+  // The TRACE_EVENT macros should only use the value as a bool.
+  // These values must be in sync with macro values in TraceEvent.h in Blink.
+  enum CategoryGroupEnabledFlags {
+    // Category group enabled for the recording mode.
+    ENABLED_FOR_RECORDING = 1 << 0,
+    // Category group enabled by SetEventCallbackEnabled().
+    ENABLED_FOR_EVENT_CALLBACK = 1 << 2,
+    // Category group enabled to export events to ETW.
+    ENABLED_FOR_ETW_EXPORT = 1 << 3
+  };
+
+  TracingController();
+  ~TracingController();
+  void Initialize(TraceBuffer* trace_buffer);
+  const uint8_t* GetCategoryGroupEnabled(const char* category_group);
+  static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
+  uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                const char* name, uint64_t handle);
+
+  void StartTracing(TraceConfig* trace_config);
+  void StopTracing();
+
+  void AddTraceStateObserver(Platform::TraceStateObserver* observer);
+  void RemoveTraceStateObserver(Platform::TraceStateObserver* observer);
+
+ private:
+  const uint8_t* GetCategoryGroupEnabledInternal(const char* category_group);
+  void UpdateCategoryGroupEnabledFlag(size_t category_index);
+  void UpdateCategoryGroupEnabledFlags();
+
+  std::unique_ptr<TraceBuffer> trace_buffer_;
+  std::unique_ptr<TraceConfig> trace_config_;
+  std::unique_ptr<base::Mutex> mutex_;
+  std::unordered_set<Platform::TraceStateObserver*> observers_;
+  Mode mode_ = DISABLED;
+
+  // Disallow copy and assign
+  TracingController(const TracingController&) = delete;
+  void operator=(const TracingController&) = delete;
+};
+
+}  // namespace tracing
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_V8_TRACING_H_
diff --git a/android/armeabi-v7a/include/v8/v8-debug.h b/android/armeabi-v7a/include/v8/v8-debug.h
new file mode 100644
index 00000000..54c0f216
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-debug.h
@@ -0,0 +1,255 @@
+// Copyright 2008 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_DEBUG_H_
+#define V8_V8_DEBUG_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * ATTENTION: The debugger API exposed by this file is deprecated and will be
+ *            removed by the end of 2017. Please use the V8 inspector declared
+ *            in include/v8-inspector.h instead.
+ */
+namespace v8 {
+
+// Debug events which can occur in the V8 JavaScript engine.
+enum DebugEvent {
+  Break = 1,
+  Exception = 2,
+  AfterCompile = 3,
+  CompileError = 4,
+  AsyncTaskEvent = 5,
+};
+
+class V8_EXPORT Debug {
+ public:
+  /**
+   * A client object passed to the v8 debugger whose ownership will be taken by
+   * it. v8 is always responsible for deleting the object.
+   */
+  class ClientData {
+   public:
+    virtual ~ClientData() {}
+  };
+
+
+  /**
+   * A message object passed to the debug message handler.
+   */
+  class Message {
+   public:
+    /**
+     * Check type of message.
+     */
+    virtual bool IsEvent() const = 0;
+    virtual bool IsResponse() const = 0;
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Indicate whether this is a response to a continue command which will
+     * start the VM running after this is processed.
+     */
+    virtual bool WillStartRunning() const = 0;
+
+    /**
+     * Access to execution state and event data. Don't store these cross
+     * callbacks as their content becomes invalid. These objects are from the
+     * debugger event that started the debug message loop.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the debugger protocol JSON.
+     */
+    virtual Local<String> GetJSON() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding request if any. This is the
+     * client_data data value passed into Debug::SendCommand along with the
+     * request that led to the message or NULL if the message is an event. The
+     * debugger takes ownership of the data and will delete it even if there is
+     * no message handler.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~Message() {}
+  };
+
+  /**
+   * An event details object passed to the debug event listener.
+   */
+  class EventDetails {
+   public:
+    /**
+     * Event type.
+     */
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Access to execution state and event data of the debug event. Don't store
+     * these cross callbacks as their content becomes invalid.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding callback when it was
+     * registered.
+     */
+    virtual Local<Value> GetCallbackData() const = 0;
+
+    /**
+     * This is now a dummy that returns nullptr.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~EventDetails() {}
+  };
+
+  /**
+   * Debug event callback function.
+   *
+   * \param event_details object providing information about the debug event
+   *
+   * A EventCallback does not take possession of the event data,
+   * and must not rely on the data persisting after the handler returns.
+   */
+  typedef void (*EventCallback)(const EventDetails& event_details);
+
+  /**
+   * This is now a no-op.
+   */
+  typedef void (*MessageHandler)(const Message& message);
+
+  V8_DEPRECATED("No longer supported", static bool SetDebugEventListener(
+                                           Isolate* isolate, EventCallback that,
+                                           Local<Value> data = Local<Value>()));
+
+  // Schedule a debugger break to happen when JavaScript code is run
+  // in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static void DebugBreak(Isolate* isolate));
+
+  // Remove scheduled debugger break in given isolate if it has not
+  // happened yet.
+  V8_DEPRECATED("No longer supported",
+                static void CancelDebugBreak(Isolate* isolate));
+
+  // Check if a debugger break is scheduled in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static bool CheckDebugBreak(Isolate* isolate));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SetMessageHandler(Isolate* isolate,
+                                              MessageHandler handler));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SendCommand(Isolate* isolate,
+                                        const uint16_t* command, int length,
+                                        ClientData* client_data = NULL));
+
+  /**
+   * Run a JavaScript function in the debugger.
+   * \param fun the function to call
+   * \param data passed as second argument to the function
+   * With this call the debugger is entered and the function specified is called
+   * with the execution state as the first argument. This makes it possible to
+   * get access to information otherwise not available during normal JavaScript
+   * execution e.g. details on stack frames. Receiver of the function call will
+   * be the debugger context global object, however this is a subject to change.
+   * The following example shows a JavaScript function which when passed to
+   * v8::Debug::Call will return the current line of JavaScript execution.
+   *
+   * \code
+   *   function frame_source_line(exec_state) {
+   *     return exec_state.frame(0).sourceLine();
+   *   }
+   * \endcode
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Value> Call(
+                    Local<Context> context, v8::Local<v8::Function> fun,
+                    Local<Value> data = Local<Value>()));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void ProcessDebugMessages(Isolate* isolate));
+
+  /**
+   * Debugger is running in its own context which is entered while debugger
+   * messages are being dispatched. This is an explicit getter for this
+   * debugger context. Note that the content of the debugger context is subject
+   * to change. The Context exists only when the debugger is active, i.e. at
+   * least one DebugEventListener or MessageHandler is set.
+   */
+  V8_DEPRECATED("Use v8-inspector",
+                static Local<Context> GetDebugContext(Isolate* isolate));
+
+  /**
+   * While in the debug context, this method returns the top-most non-debug
+   * context, if it exists.
+   */
+  V8_DEPRECATED(
+      "No longer supported",
+      static MaybeLocal<Context> GetDebuggedContext(Isolate* isolate));
+
+  /**
+   * Enable/disable LiveEdit functionality for the given Isolate
+   * (default Isolate if not provided). V8 will abort if LiveEdit is
+   * unexpectedly used. LiveEdit is enabled by default.
+   */
+  V8_DEPRECATED("No longer supported",
+                static void SetLiveEditEnabled(Isolate* isolate, bool enable));
+
+  /**
+   * Returns array of internal properties specific to the value type. Result has
+   * the following format: [<name>, <value>,...,<name>, <value>]. Result array
+   * will be allocated in the current context.
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Array> GetInternalProperties(
+                    Isolate* isolate, Local<Value> value));
+
+  /**
+   * Defines if the ES2015 tail call elimination feature is enabled or not.
+   * The change of this flag triggers deoptimization of all functions that
+   * contain calls at tail position.
+   */
+  V8_DEPRECATED("No longer supported",
+                static bool IsTailCallEliminationEnabled(Isolate* isolate));
+  V8_DEPRECATED("No longer supported",
+                static void SetTailCallEliminationEnabled(Isolate* isolate,
+                                                          bool enabled));
+};
+
+
+}  // namespace v8
+
+
+#undef EXPORT
+
+
+#endif  // V8_V8_DEBUG_H_
diff --git a/android/armeabi-v7a/include/v8/v8-inspector-protocol.h b/android/armeabi-v7a/include/v8/v8-inspector-protocol.h
new file mode 100644
index 00000000..612a2ebc
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-inspector-protocol.h
@@ -0,0 +1,13 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_PROTOCOL_H_
+#define V8_V8_INSPECTOR_PROTOCOL_H_
+
+#include "inspector/Debugger.h"  // NOLINT(build/include)
+#include "inspector/Runtime.h"   // NOLINT(build/include)
+#include "inspector/Schema.h"    // NOLINT(build/include)
+#include "v8-inspector.h"        // NOLINT(build/include)
+
+#endif  // V8_V8_INSPECTOR_PROTOCOL_H_
diff --git a/android/armeabi-v7a/include/v8/v8-inspector.h b/android/armeabi-v7a/include/v8/v8-inspector.h
new file mode 100644
index 00000000..43bf3b4f
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-inspector.h
@@ -0,0 +1,267 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_H_
+#define V8_V8_INSPECTOR_H_
+
+#include <stdint.h>
+#include <cctype>
+
+#include <memory>
+
+#include "v8.h"  // NOLINT(build/include)
+
+namespace v8_inspector {
+
+namespace protocol {
+namespace Debugger {
+namespace API {
+class SearchMatch;
+}
+}
+namespace Runtime {
+namespace API {
+class RemoteObject;
+class StackTrace;
+}
+}
+namespace Schema {
+namespace API {
+class Domain;
+}
+}
+}  // namespace protocol
+
+class V8_EXPORT StringView {
+ public:
+  StringView() : m_is8Bit(true), m_length(0), m_characters8(nullptr) {}
+
+  StringView(const uint8_t* characters, size_t length)
+      : m_is8Bit(true), m_length(length), m_characters8(characters) {}
+
+  StringView(const uint16_t* characters, size_t length)
+      : m_is8Bit(false), m_length(length), m_characters16(characters) {}
+
+  bool is8Bit() const { return m_is8Bit; }
+  size_t length() const { return m_length; }
+
+  // TODO(dgozman): add DCHECK(m_is8Bit) to accessors once platform can be used
+  // here.
+  const uint8_t* characters8() const { return m_characters8; }
+  const uint16_t* characters16() const { return m_characters16; }
+
+ private:
+  bool m_is8Bit;
+  size_t m_length;
+  union {
+    const uint8_t* m_characters8;
+    const uint16_t* m_characters16;
+  };
+};
+
+class V8_EXPORT StringBuffer {
+ public:
+  virtual ~StringBuffer() {}
+  virtual const StringView& string() = 0;
+  // This method copies contents.
+  static std::unique_ptr<StringBuffer> create(const StringView&);
+};
+
+class V8_EXPORT V8ContextInfo {
+ public:
+  V8ContextInfo(v8::Local<v8::Context> context, int contextGroupId,
+                const StringView& humanReadableName)
+      : context(context),
+        contextGroupId(contextGroupId),
+        humanReadableName(humanReadableName),
+        hasMemoryOnConsole(false) {}
+
+  v8::Local<v8::Context> context;
+  // Each v8::Context is a part of a group. The group id must be non-zero.
+  int contextGroupId;
+  StringView humanReadableName;
+  StringView origin;
+  StringView auxData;
+  bool hasMemoryOnConsole;
+
+  static int executionContextId(v8::Local<v8::Context> context);
+
+ private:
+  // Disallow copying and allocating this one.
+  enum NotNullTagEnum { NotNullLiteral };
+  void* operator new(size_t) = delete;
+  void* operator new(size_t, NotNullTagEnum, void*) = delete;
+  void* operator new(size_t, void*) = delete;
+  V8ContextInfo(const V8ContextInfo&) = delete;
+  V8ContextInfo& operator=(const V8ContextInfo&) = delete;
+};
+
+class V8_EXPORT V8StackTrace {
+ public:
+  virtual bool isEmpty() const = 0;
+  virtual StringView topSourceURL() const = 0;
+  virtual int topLineNumber() const = 0;
+  virtual int topColumnNumber() const = 0;
+  virtual StringView topScriptId() const = 0;
+  virtual StringView topFunctionName() const = 0;
+
+  virtual ~V8StackTrace() {}
+  virtual std::unique_ptr<protocol::Runtime::API::StackTrace>
+  buildInspectorObject() const = 0;
+  virtual std::unique_ptr<StringBuffer> toString() const = 0;
+
+  // Safe to pass between threads, drops async chain.
+  virtual std::unique_ptr<V8StackTrace> clone() = 0;
+};
+
+class V8_EXPORT V8InspectorSession {
+ public:
+  virtual ~V8InspectorSession() {}
+
+  // Cross-context inspectable values (DOM nodes in different worlds, etc.).
+  class V8_EXPORT Inspectable {
+   public:
+    virtual v8::Local<v8::Value> get(v8::Local<v8::Context>) = 0;
+    virtual ~Inspectable() {}
+  };
+  virtual void addInspectedObject(std::unique_ptr<Inspectable>) = 0;
+
+  // Dispatching protocol messages.
+  static bool canDispatchMethod(const StringView& method);
+  virtual void dispatchProtocolMessage(const StringView& message) = 0;
+  virtual std::unique_ptr<StringBuffer> stateJSON() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Schema::API::Domain>>
+  supportedDomains() = 0;
+
+  // Debugger actions.
+  virtual void schedulePauseOnNextStatement(const StringView& breakReason,
+                                            const StringView& breakDetails) = 0;
+  virtual void cancelPauseOnNextStatement() = 0;
+  virtual void breakProgram(const StringView& breakReason,
+                            const StringView& breakDetails) = 0;
+  virtual void setSkipAllPauses(bool) = 0;
+  virtual void resume() = 0;
+  virtual void stepOver() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Debugger::API::SearchMatch>>
+  searchInTextByLines(const StringView& text, const StringView& query,
+                      bool caseSensitive, bool isRegex) = 0;
+
+  // Remote objects.
+  virtual std::unique_ptr<protocol::Runtime::API::RemoteObject> wrapObject(
+      v8::Local<v8::Context>, v8::Local<v8::Value>,
+      const StringView& groupName) = 0;
+  virtual bool unwrapObject(std::unique_ptr<StringBuffer>* error,
+                            const StringView& objectId, v8::Local<v8::Value>*,
+                            v8::Local<v8::Context>*,
+                            std::unique_ptr<StringBuffer>* objectGroup) = 0;
+  virtual void releaseObjectGroup(const StringView&) = 0;
+};
+
+class V8_EXPORT V8InspectorClient {
+ public:
+  virtual ~V8InspectorClient() {}
+
+  virtual void runMessageLoopOnPause(int contextGroupId) {}
+  virtual void quitMessageLoopOnPause() {}
+  virtual void runIfWaitingForDebugger(int contextGroupId) {}
+
+  virtual void muteMetrics(int contextGroupId) {}
+  virtual void unmuteMetrics(int contextGroupId) {}
+
+  virtual void beginUserGesture() {}
+  virtual void endUserGesture() {}
+
+  virtual std::unique_ptr<StringBuffer> valueSubtype(v8::Local<v8::Value>) {
+    return nullptr;
+  }
+  virtual bool formatAccessorsAsProperties(v8::Local<v8::Value>) {
+    return false;
+  }
+  virtual bool isInspectableHeapObject(v8::Local<v8::Object>) { return true; }
+
+  virtual v8::Local<v8::Context> ensureDefaultContextInGroup(
+      int contextGroupId) {
+    return v8::Local<v8::Context>();
+  }
+  virtual void beginEnsureAllContextsInGroup(int contextGroupId) {}
+  virtual void endEnsureAllContextsInGroup(int contextGroupId) {}
+
+  virtual void installAdditionalCommandLineAPI(v8::Local<v8::Context>,
+                                               v8::Local<v8::Object>) {}
+  virtual void consoleAPIMessage(int contextGroupId,
+                                 v8::Isolate::MessageErrorLevel level,
+                                 const StringView& message,
+                                 const StringView& url, unsigned lineNumber,
+                                 unsigned columnNumber, V8StackTrace*) {}
+  virtual v8::MaybeLocal<v8::Value> memoryInfo(v8::Isolate*,
+                                               v8::Local<v8::Context>) {
+    return v8::MaybeLocal<v8::Value>();
+  }
+
+  virtual void consoleTime(const StringView& title) {}
+  virtual void consoleTimeEnd(const StringView& title) {}
+  virtual void consoleTimeStamp(const StringView& title) {}
+  virtual void consoleClear(int contextGroupId) {}
+  virtual double currentTimeMS() { return 0; }
+  typedef void (*TimerCallback)(void*);
+  virtual void startRepeatingTimer(double, TimerCallback, void* data) {}
+  virtual void cancelTimer(void* data) {}
+
+  // TODO(dgozman): this was added to support service worker shadow page. We
+  // should not connect at all.
+  virtual bool canExecuteScripts(int contextGroupId) { return true; }
+};
+
+class V8_EXPORT V8Inspector {
+ public:
+  static std::unique_ptr<V8Inspector> create(v8::Isolate*, V8InspectorClient*);
+  virtual ~V8Inspector() {}
+
+  // Contexts instrumentation.
+  virtual void contextCreated(const V8ContextInfo&) = 0;
+  virtual void contextDestroyed(v8::Local<v8::Context>) = 0;
+  virtual void resetContextGroup(int contextGroupId) = 0;
+
+  // Various instrumentation.
+  virtual void idleStarted() = 0;
+  virtual void idleFinished() = 0;
+
+  // Async stack traces instrumentation.
+  virtual void asyncTaskScheduled(const StringView& taskName, void* task,
+                                  bool recurring) = 0;
+  virtual void asyncTaskCanceled(void* task) = 0;
+  virtual void asyncTaskStarted(void* task) = 0;
+  virtual void asyncTaskFinished(void* task) = 0;
+  virtual void allAsyncTasksCanceled() = 0;
+
+  // Exceptions instrumentation.
+  virtual unsigned exceptionThrown(
+      v8::Local<v8::Context>, const StringView& message,
+      v8::Local<v8::Value> exception, const StringView& detailedMessage,
+      const StringView& url, unsigned lineNumber, unsigned columnNumber,
+      std::unique_ptr<V8StackTrace>, int scriptId) = 0;
+  virtual void exceptionRevoked(v8::Local<v8::Context>, unsigned exceptionId,
+                                const StringView& message) = 0;
+
+  // Connection.
+  class V8_EXPORT Channel {
+   public:
+    virtual ~Channel() {}
+    virtual void sendResponse(int callId,
+                              std::unique_ptr<StringBuffer> message) = 0;
+    virtual void sendNotification(std::unique_ptr<StringBuffer> message) = 0;
+    virtual void flushProtocolNotifications() = 0;
+  };
+  virtual std::unique_ptr<V8InspectorSession> connect(
+      int contextGroupId, Channel*, const StringView& state) = 0;
+
+  // API methods.
+  virtual std::unique_ptr<V8StackTrace> createStackTrace(
+      v8::Local<v8::StackTrace>) = 0;
+  virtual std::unique_ptr<V8StackTrace> captureStackTrace(bool fullStack) = 0;
+};
+
+}  // namespace v8_inspector
+
+#endif  // V8_V8_INSPECTOR_H_
diff --git a/android/armeabi-v7a/include/v8/v8-platform.h b/android/armeabi-v7a/include/v8/v8-platform.h
new file mode 100644
index 00000000..8f6d8042
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-platform.h
@@ -0,0 +1,227 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PLATFORM_H_
+#define V8_V8_PLATFORM_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <memory>
+#include <string>
+
+namespace v8 {
+
+class Isolate;
+
+/**
+ * A Task represents a unit of work.
+ */
+class Task {
+ public:
+  virtual ~Task() = default;
+
+  virtual void Run() = 0;
+};
+
+/**
+ * An IdleTask represents a unit of work to be performed in idle time.
+ * The Run method is invoked with an argument that specifies the deadline in
+ * seconds returned by MonotonicallyIncreasingTime().
+ * The idle task is expected to complete by this deadline.
+ */
+class IdleTask {
+ public:
+  virtual ~IdleTask() = default;
+  virtual void Run(double deadline_in_seconds) = 0;
+};
+
+/**
+ * The interface represents complex arguments to trace events.
+ */
+class ConvertableToTraceFormat {
+ public:
+  virtual ~ConvertableToTraceFormat() = default;
+
+  /**
+   * Append the class info to the provided |out| string. The appended
+   * data must be a valid JSON object. Strings must be properly quoted, and
+   * escaped. There is no processing applied to the content after it is
+   * appended.
+   */
+  virtual void AppendAsTraceFormat(std::string* out) const = 0;
+};
+
+/**
+ * V8 Platform abstraction layer.
+ *
+ * The embedder has to provide an implementation of this interface before
+ * initializing the rest of V8.
+ */
+class Platform {
+ public:
+  /**
+   * This enum is used to indicate whether a task is potentially long running,
+   * or causes a long wait. The embedder might want to use this hint to decide
+   * whether to execute the task on a dedicated thread.
+   */
+  enum ExpectedRuntime {
+    kShortRunningTask,
+    kLongRunningTask
+  };
+
+  virtual ~Platform() = default;
+
+  /**
+   * Gets the number of threads that are used to execute background tasks. Is
+   * used to estimate the number of tasks a work package should be split into.
+   * A return value of 0 means that there are no background threads available.
+   * Note that a value of 0 won't prohibit V8 from posting tasks using
+   * |CallOnBackgroundThread|.
+   */
+  virtual size_t NumberOfAvailableBackgroundThreads() { return 0; }
+
+  /**
+   * Schedules a task to be invoked on a background thread. |expected_runtime|
+   * indicates that the task will run a long time. The Platform implementation
+   * takes ownership of |task|. There is no guarantee about order of execution
+   * of tasks wrt order of scheduling, nor is there a guarantee about the
+   * thread the task will be run on.
+   */
+  virtual void CallOnBackgroundThread(Task* task,
+                                      ExpectedRuntime expected_runtime) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate|. Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallOnForegroundThread(Isolate* isolate, Task* task) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| after the given number of seconds |delay_in_seconds|.
+   * Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallDelayedOnForegroundThread(Isolate* isolate, Task* task,
+                                             double delay_in_seconds) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| when the embedder is idle.
+   * Requires that SupportsIdleTasks(isolate) is true.
+   * Idle tasks may be reordered relative to other task types and may be
+   * starved for an arbitrarily long time if no idle time is available.
+   * The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallIdleOnForegroundThread(Isolate* isolate, IdleTask* task) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+  }
+
+  /**
+   * Returns true if idle tasks are enabled for the given |isolate|.
+   */
+  virtual bool IdleTasksEnabled(Isolate* isolate) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+    return false;
+  }
+
+  /**
+   * Monotonically increasing time in seconds from an arbitrary fixed point in
+   * the past. This function is expected to return at least
+   * millisecond-precision values. For this reason,
+   * it is recommended that the fixed point be no further in the past than
+   * the epoch.
+   **/
+  virtual double MonotonicallyIncreasingTime() = 0;
+
+  /**
+   * Called by TRACE_EVENT* macros, don't call this directly.
+   * The name parameter is a category group for example:
+   * TRACE_EVENT0("v8,parse", "V8.Parse")
+   * The pointer returned points to a value with zero or more of the bits
+   * defined in CategoryGroupEnabledFlags.
+   **/
+  virtual const uint8_t* GetCategoryGroupEnabled(const char* name) {
+    static uint8_t no = 0;
+    return &no;
+  }
+
+  /**
+   * Gets the category group name of the given category_enabled_flag pointer.
+   * Usually used while serliazing TRACE_EVENTs.
+   **/
+  virtual const char* GetCategoryGroupName(
+      const uint8_t* category_enabled_flag) {
+    static const char dummy[] = "dummy";
+    return dummy;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values, unsigned int flags) {
+    return 0;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags) {
+    return AddTraceEvent(phase, category_enabled_flag, name, scope, id, bind_id,
+                         num_args, arg_names, arg_types, arg_values, flags);
+  }
+
+  /**
+   * Sets the duration field of a COMPLETE trace event. It must be called with
+   * the handle returned from AddTraceEvent().
+   **/
+  virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                        const char* name, uint64_t handle) {}
+
+  class TraceStateObserver {
+   public:
+    virtual ~TraceStateObserver() = default;
+    virtual void OnTraceEnabled() = 0;
+    virtual void OnTraceDisabled() = 0;
+  };
+
+  /** Adds tracing state change observer. */
+  virtual void AddTraceStateObserver(TraceStateObserver*) {}
+
+  /** Removes tracing state change observer. */
+  virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
+
+  typedef void (*StackTracePrinter)();
+
+  /**
+   * Returns a function pointer that print a stack trace of the current stack
+   * on invocation. Disables printing of the stack trace if nullptr.
+   */
+  virtual StackTracePrinter GetStackTracePrinter() { return nullptr; }
+};
+
+}  // namespace v8
+
+#endif  // V8_V8_PLATFORM_H_
diff --git a/android/armeabi-v7a/include/v8/v8-profiler.h b/android/armeabi-v7a/include/v8/v8-profiler.h
new file mode 100644
index 00000000..b60d137f
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-profiler.h
@@ -0,0 +1,912 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PROFILER_H_
+#define V8_V8_PROFILER_H_
+
+#include <unordered_set>
+#include <vector>
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Profiler support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class HeapGraphNode;
+struct HeapStatsUpdate;
+
+typedef uint32_t SnapshotObjectId;
+
+
+struct CpuProfileDeoptFrame {
+  int script_id;
+  size_t position;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptFrame>;
+#endif
+
+namespace v8 {
+
+struct V8_EXPORT CpuProfileDeoptInfo {
+  /** A pointer to a static string owned by v8. */
+  const char* deopt_reason;
+  std::vector<CpuProfileDeoptFrame> stack;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>;
+#endif
+
+namespace v8 {
+
+/**
+ * TracingCpuProfiler monitors tracing being enabled/disabled
+ * and emits CpuProfile trace events once v8.cpu_profiler tracing category
+ * is enabled. It has no overhead unless the category is enabled.
+ */
+class V8_EXPORT TracingCpuProfiler {
+ public:
+  static std::unique_ptr<TracingCpuProfiler> Create(Isolate*);
+  virtual ~TracingCpuProfiler() = default;
+
+ protected:
+  TracingCpuProfiler() = default;
+};
+
+// TickSample captures the information collected for each sample.
+struct TickSample {
+  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
+  // include the runtime function we're calling. Externally exposed tick
+  // samples don't care.
+  enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame };
+
+  TickSample()
+      : state(OTHER),
+        pc(nullptr),
+        external_callback_entry(nullptr),
+        frames_count(0),
+        has_external_callback(false),
+        update_stats(true) {}
+
+  /**
+   * Initialize a tick sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Execution state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param update_stats Whether update the sample to the aggregated stats.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   */
+  void Init(Isolate* isolate, const v8::RegisterState& state,
+            RecordCEntryFrame record_c_entry_frame, bool update_stats,
+            bool use_simulator_reg_state = true);
+  /**
+   * Get a call stack sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Register state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   * \note GetStackSample is thread and signal safe and should only be called
+   *                      when the JS thread is paused or interrupted.
+   *                      Otherwise the behavior is undefined.
+   */
+  static bool GetStackSample(Isolate* isolate, v8::RegisterState* state,
+                             RecordCEntryFrame record_c_entry_frame,
+                             void** frames, size_t frames_limit,
+                             v8::SampleInfo* sample_info,
+                             bool use_simulator_reg_state = true);
+  StateTag state;  // The state of the VM.
+  void* pc;        // Instruction pointer.
+  union {
+    void* tos;  // Top stack value (*sp).
+    void* external_callback_entry;
+  };
+  static const unsigned kMaxFramesCountLog2 = 8;
+  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
+  void* stack[kMaxFramesCount];                 // Call stack.
+  unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
+  bool has_external_callback : 1;
+  bool update_stats : 1;  // Whether the sample should update aggregated stats.
+};
+
+/**
+ * CpuProfileNode represents a node in a call graph.
+ */
+class V8_EXPORT CpuProfileNode {
+ public:
+  struct LineTick {
+    /** The 1-based number of the source line where the function originates. */
+    int line;
+
+    /** The count of samples associated with the source line. */
+    unsigned int hit_count;
+  };
+
+  /** Returns function name (empty string for anonymous functions.) */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns function name (empty string for anonymous functions.)
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetFunctionNameStr() const;
+
+  /** Returns id of the script where function is located. */
+  int GetScriptId() const;
+
+  /** Returns resource name for script from where the function originates. */
+  Local<String> GetScriptResourceName() const;
+
+  /**
+   * Returns resource name for script from where the function originates.
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetScriptResourceNameStr() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the function originates.
+   * kNoLineNumberInfo if no line number information is available.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns 1-based number of the column where the function originates.
+   * kNoColumnNumberInfo if no column number information is available.
+   */
+  int GetColumnNumber() const;
+
+  /**
+   * Returns the number of the function's source lines that collect the samples.
+   */
+  unsigned int GetHitLineCount() const;
+
+  /** Returns the set of source lines that collect the samples.
+   *  The caller allocates buffer and responsible for releasing it.
+   *  True if all available entries are copied, otherwise false.
+   *  The function copies nothing if buffer is not large enough.
+   */
+  bool GetLineTicks(LineTick* entries, unsigned int length) const;
+
+  /** Returns bailout reason for the function
+    * if the optimization was disabled for it.
+    */
+  const char* GetBailoutReason() const;
+
+  /**
+    * Returns the count of samples where the function was currently executing.
+    */
+  unsigned GetHitCount() const;
+
+  /** Returns function entry UID. */
+  V8_DEPRECATE_SOON(
+      "Use GetScriptId, GetLineNumber, and GetColumnNumber instead.",
+      unsigned GetCallUid() const);
+
+  /** Returns id of the node. The id is unique within the tree */
+  unsigned GetNodeId() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child node by index. */
+  const CpuProfileNode* GetChild(int index) const;
+
+  /** Retrieves deopt infos for the node. */
+  const std::vector<CpuProfileDeoptInfo>& GetDeoptInfos() const;
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * CpuProfile contains a CPU profile in a form of top-down call tree
+ * (from main() down to functions that do all the work).
+ */
+class V8_EXPORT CpuProfile {
+ public:
+  /** Returns CPU profile title. */
+  Local<String> GetTitle() const;
+
+  /** Returns the root node of the top down call tree. */
+  const CpuProfileNode* GetTopDownRoot() const;
+
+  /**
+   * Returns number of samples recorded. The samples are not recorded unless
+   * |record_samples| parameter of CpuProfiler::StartCpuProfiling is true.
+   */
+  int GetSamplesCount() const;
+
+  /**
+   * Returns profile node corresponding to the top frame the sample at
+   * the given index.
+   */
+  const CpuProfileNode* GetSample(int index) const;
+
+  /**
+   * Returns the timestamp of the sample. The timestamp is the number of
+   * microseconds since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetSampleTimestamp(int index) const;
+
+  /**
+   * Returns time when the profile recording was started (in microseconds)
+   * since some unspecified starting point.
+   */
+  int64_t GetStartTime() const;
+
+  /**
+   * Returns time when the profile recording was stopped (in microseconds)
+   * since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetEndTime() const;
+
+  /**
+   * Deletes the profile and removes it from CpuProfiler's list.
+   * All pointers to nodes previously returned become invalid.
+   */
+  void Delete();
+};
+
+/**
+ * Interface for controlling CPU profiling. Instance of the
+ * profiler can be created using v8::CpuProfiler::New method.
+ */
+class V8_EXPORT CpuProfiler {
+ public:
+  /**
+   * Creates a new CPU profiler for the |isolate|. The isolate must be
+   * initialized. The profiler object must be disposed after use by calling
+   * |Dispose| method.
+   */
+  static CpuProfiler* New(Isolate* isolate);
+
+  /**
+   * Disposes the CPU profiler object.
+   */
+  void Dispose();
+
+  /**
+   * Changes default CPU profiler sampling interval to the specified number
+   * of microseconds. Default interval is 1000us. This method must be called
+   * when there are no profiles being recorded.
+   */
+  void SetSamplingInterval(int us);
+
+  /**
+   * Starts collecting CPU profile. Title may be an empty string. It
+   * is allowed to have several profiles being collected at
+   * once. Attempts to start collecting several profiles with the same
+   * title are silently ignored. While collecting a profile, functions
+   * from all security contexts are included in it. The token-based
+   * filtering is only performed when querying for a profile.
+   *
+   * |record_samples| parameter controls whether individual samples should
+   * be recorded in addition to the aggregated tree.
+   */
+  void StartProfiling(Local<String> title, bool record_samples = false);
+
+  /**
+   * Stops collecting CPU profile with a given title and returns it.
+   * If the title given is empty, finishes the last profile started.
+   */
+  CpuProfile* StopProfiling(Local<String> title);
+
+  /**
+   * Force collection of a sample. Must be called on the VM thread.
+   * Recording the forced sample does not contribute to the aggregated
+   * profile statistics.
+   */
+  void CollectSample();
+
+  /**
+   * Tells the profiler whether the embedder is idle.
+   */
+  void SetIdle(bool is_idle);
+
+ private:
+  CpuProfiler();
+  ~CpuProfiler();
+  CpuProfiler(const CpuProfiler&);
+  CpuProfiler& operator=(const CpuProfiler&);
+};
+
+
+/**
+ * HeapSnapshotEdge represents a directed connection between heap
+ * graph nodes: from retainers to retained nodes.
+ */
+class V8_EXPORT HeapGraphEdge {
+ public:
+  enum Type {
+    kContextVariable = 0,  // A variable from a function context.
+    kElement = 1,          // An element of an array.
+    kProperty = 2,         // A named object property.
+    kInternal = 3,         // A link that can't be accessed from JS,
+                           // thus, its name isn't a real property name
+                           // (e.g. parts of a ConsString).
+    kHidden = 4,           // A link that is needed for proper sizes
+                           // calculation, but may be hidden from user.
+    kShortcut = 5,         // A link that must not be followed during
+                           // sizes calculation.
+    kWeak = 6              // A weak reference (ignored by the GC).
+  };
+
+  /** Returns edge type (see HeapGraphEdge::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns edge name. This can be a variable name, an element index, or
+   * a property name.
+   */
+  Local<Value> GetName() const;
+
+  /** Returns origin node. */
+  const HeapGraphNode* GetFromNode() const;
+
+  /** Returns destination node. */
+  const HeapGraphNode* GetToNode() const;
+};
+
+
+/**
+ * HeapGraphNode represents a node in a heap graph.
+ */
+class V8_EXPORT HeapGraphNode {
+ public:
+  enum Type {
+    kHidden = 0,         // Hidden node, may be filtered when shown to user.
+    kArray = 1,          // An array of elements.
+    kString = 2,         // A string.
+    kObject = 3,         // A JS object (except for arrays and strings).
+    kCode = 4,           // Compiled code.
+    kClosure = 5,        // Function closure.
+    kRegExp = 6,         // RegExp.
+    kHeapNumber = 7,     // Number stored in the heap.
+    kNative = 8,         // Native object (not from V8 heap).
+    kSynthetic = 9,      // Synthetic object, usualy used for grouping
+                         // snapshot items together.
+    kConsString = 10,    // Concatenated string. A pair of pointers to strings.
+    kSlicedString = 11,  // Sliced string. A fragment of another string.
+    kSymbol = 12         // A Symbol (ES6).
+  };
+
+  /** Returns node type (see HeapGraphNode::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns node name. Depending on node's type this can be the name
+   * of the constructor (for objects), the name of the function (for
+   * closures), string value, or an empty string (for compiled code).
+   */
+  Local<String> GetName() const;
+
+  /**
+   * Returns node id. For the same heap object, the id remains the same
+   * across all snapshots.
+   */
+  SnapshotObjectId GetId() const;
+
+  /** Returns node's own size, in bytes. */
+  size_t GetShallowSize() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child by index. */
+  const HeapGraphEdge* GetChild(int index) const;
+};
+
+
+/**
+ * An interface for exporting data from V8, using "push" model.
+ */
+class V8_EXPORT OutputStream {  // NOLINT
+ public:
+  enum WriteResult {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~OutputStream() {}
+  /** Notify about the end of stream. */
+  virtual void EndOfStream() = 0;
+  /** Get preferred output chunk size. Called only once. */
+  virtual int GetChunkSize() { return 1024; }
+  /**
+   * Writes the next chunk of snapshot data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteAsciiChunk(char* data, int size) = 0;
+  /**
+   * Writes the next chunk of heap stats data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate* data, int count) {
+    return kAbort;
+  }
+};
+
+
+/**
+ * HeapSnapshots record the state of the JS heap at some moment.
+ */
+class V8_EXPORT HeapSnapshot {
+ public:
+  enum SerializationFormat {
+    kJSON = 0  // See format description near 'Serialize' method.
+  };
+
+  /** Returns the root node of the heap graph. */
+  const HeapGraphNode* GetRoot() const;
+
+  /** Returns a node by its id. */
+  const HeapGraphNode* GetNodeById(SnapshotObjectId id) const;
+
+  /** Returns total nodes count in the snapshot. */
+  int GetNodesCount() const;
+
+  /** Returns a node by index. */
+  const HeapGraphNode* GetNode(int index) const;
+
+  /** Returns a max seen JS object Id. */
+  SnapshotObjectId GetMaxSnapshotJSObjectId() const;
+
+  /**
+   * Deletes the snapshot and removes it from HeapProfiler's list.
+   * All pointers to nodes, edges and paths previously returned become
+   * invalid.
+   */
+  void Delete();
+
+  /**
+   * Prepare a serialized representation of the snapshot. The result
+   * is written into the stream provided in chunks of specified size.
+   * The total length of the serialized snapshot is unknown in
+   * advance, it can be roughly equal to JS heap size (that means,
+   * it can be really big - tens of megabytes).
+   *
+   * For the JSON format, heap contents are represented as an object
+   * with the following structure:
+   *
+   *  {
+   *    snapshot: {
+   *      title: "...",
+   *      uid: nnn,
+   *      meta: { meta-info },
+   *      node_count: nnn,
+   *      edge_count: nnn
+   *    },
+   *    nodes: [nodes array],
+   *    edges: [edges array],
+   *    strings: [strings array]
+   *  }
+   *
+   * Nodes reference strings, other nodes, and edges by their indexes
+   * in corresponding arrays.
+   */
+  void Serialize(OutputStream* stream,
+                 SerializationFormat format = kJSON) const;
+};
+
+
+/**
+ * An interface for reporting progress and controlling long-running
+ * activities.
+ */
+class V8_EXPORT ActivityControl {  // NOLINT
+ public:
+  enum ControlOption {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~ActivityControl() {}
+  /**
+   * Notify about current progress. The activity can be stopped by
+   * returning kAbort as the callback result.
+   */
+  virtual ControlOption ReportProgressValue(int done, int total) = 0;
+};
+
+
+/**
+ * AllocationProfile is a sampled profile of allocations done by the program.
+ * This is structured as a call-graph.
+ */
+class V8_EXPORT AllocationProfile {
+ public:
+  struct Allocation {
+    /**
+     * Size of the sampled allocation object.
+     */
+    size_t size;
+
+    /**
+     * The number of objects of such size that were sampled.
+     */
+    unsigned int count;
+  };
+
+  /**
+   * Represents a node in the call-graph.
+   */
+  struct Node {
+    /**
+     * Name of the function. May be empty for anonymous functions or if the
+     * script corresponding to this function has been unloaded.
+     */
+    Local<String> name;
+
+    /**
+     * Name of the script containing the function. May be empty if the script
+     * name is not available, or if the script has been unloaded.
+     */
+    Local<String> script_name;
+
+    /**
+     * id of the script where the function is located. May be equal to
+     * v8::UnboundScript::kNoScriptId in cases where the script doesn't exist.
+     */
+    int script_id;
+
+    /**
+     * Start position of the function in the script.
+     */
+    int start_position;
+
+    /**
+     * 1-indexed line number where the function starts. May be
+     * kNoLineNumberInfo if no line number information is available.
+     */
+    int line_number;
+
+    /**
+     * 1-indexed column number where the function starts. May be
+     * kNoColumnNumberInfo if no line number information is available.
+     */
+    int column_number;
+
+    /**
+     * List of callees called from this node for which we have sampled
+     * allocations. The lifetime of the children is scoped to the containing
+     * AllocationProfile.
+     */
+    std::vector<Node*> children;
+
+    /**
+     * List of self allocations done by this node in the call-graph.
+     */
+    std::vector<Allocation> allocations;
+  };
+
+  /**
+   * Returns the root node of the call-graph. The root node corresponds to an
+   * empty JS call-stack. The lifetime of the returned Node* is scoped to the
+   * containing AllocationProfile.
+   */
+  virtual Node* GetRootNode() = 0;
+
+  virtual ~AllocationProfile() {}
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * Interface for controlling heap profiling. Instance of the
+ * profiler can be retrieved using v8::Isolate::GetHeapProfiler.
+ */
+class V8_EXPORT HeapProfiler {
+ public:
+  enum SamplingFlags {
+    kSamplingNoFlags = 0,
+    kSamplingForceGC = 1 << 0,
+  };
+
+  typedef std::unordered_set<const v8::PersistentBase<v8::Value>*>
+      RetainerChildren;
+  typedef std::vector<std::pair<v8::RetainedObjectInfo*, RetainerChildren>>
+      RetainerGroups;
+  typedef std::vector<std::pair<const v8::PersistentBase<v8::Value>*,
+                                const v8::PersistentBase<v8::Value>*>>
+      RetainerEdges;
+
+  struct RetainerInfos {
+    RetainerGroups groups;
+    RetainerEdges edges;
+  };
+
+  /**
+   * Callback function invoked to retrieve all RetainerInfos from the embedder.
+   */
+  typedef RetainerInfos (*GetRetainerInfosCallback)(v8::Isolate* isolate);
+
+  /**
+   * Callback function invoked for obtaining RetainedObjectInfo for
+   * the given JavaScript wrapper object. It is prohibited to enter V8
+   * while the callback is running: only getters on the handle and
+   * GetPointerFromInternalField on the objects are allowed.
+   */
+  typedef RetainedObjectInfo* (*WrapperInfoCallback)(uint16_t class_id,
+                                                     Local<Value> wrapper);
+
+  /** Returns the number of snapshots taken. */
+  int GetSnapshotCount();
+
+  /** Returns a snapshot by index. */
+  const HeapSnapshot* GetHeapSnapshot(int index);
+
+  /**
+   * Returns SnapshotObjectId for a heap object referenced by |value| if
+   * it has been seen by the heap profiler, kUnknownObjectId otherwise.
+   */
+  SnapshotObjectId GetObjectId(Local<Value> value);
+
+  /**
+   * Returns heap object with given SnapshotObjectId if the object is alive,
+   * otherwise empty handle is returned.
+   */
+  Local<Value> FindObjectById(SnapshotObjectId id);
+
+  /**
+   * Clears internal map from SnapshotObjectId to heap object. The new objects
+   * will not be added into it unless a heap snapshot is taken or heap object
+   * tracking is kicked off.
+   */
+  void ClearObjectIds();
+
+  /**
+   * A constant for invalid SnapshotObjectId. GetSnapshotObjectId will return
+   * it in case heap profiler cannot find id  for the object passed as
+   * parameter. HeapSnapshot::GetNodeById will always return NULL for such id.
+   */
+  static const SnapshotObjectId kUnknownObjectId = 0;
+
+  /**
+   * Callback interface for retrieving user friendly names of global objects.
+   */
+  class ObjectNameResolver {
+   public:
+    /**
+     * Returns name to be used in the heap snapshot for given node. Returned
+     * string must stay alive until snapshot collection is completed.
+     */
+    virtual const char* GetName(Local<Object> object) = 0;
+
+   protected:
+    virtual ~ObjectNameResolver() {}
+  };
+
+  /**
+   * Takes a heap snapshot and returns it.
+   */
+  const HeapSnapshot* TakeHeapSnapshot(
+      ActivityControl* control = NULL,
+      ObjectNameResolver* global_object_name_resolver = NULL);
+
+  /**
+   * Starts tracking of heap objects population statistics. After calling
+   * this method, all heap objects relocations done by the garbage collector
+   * are being registered.
+   *
+   * |track_allocations| parameter controls whether stack trace of each
+   * allocation in the heap will be recorded and reported as part of
+   * HeapSnapshot.
+   */
+  void StartTrackingHeapObjects(bool track_allocations = false);
+
+  /**
+   * Adds a new time interval entry to the aggregated statistics array. The
+   * time interval entry contains information on the current heap objects
+   * population size. The method also updates aggregated statistics and
+   * reports updates for all previous time intervals via the OutputStream
+   * object. Updates on each time interval are provided as a stream of the
+   * HeapStatsUpdate structure instances.
+   * If |timestamp_us| is supplied, timestamp of the new entry will be written
+   * into it. The return value of the function is the last seen heap object Id.
+   *
+   * StartTrackingHeapObjects must be called before the first call to this
+   * method.
+   */
+  SnapshotObjectId GetHeapStats(OutputStream* stream,
+                                int64_t* timestamp_us = NULL);
+
+  /**
+   * Stops tracking of heap objects population statistics, cleans up all
+   * collected data. StartHeapObjectsTracking must be called again prior to
+   * calling GetHeapStats next time.
+   */
+  void StopTrackingHeapObjects();
+
+  /**
+   * Starts gathering a sampling heap profile. A sampling heap profile is
+   * similar to tcmalloc's heap profiler and Go's mprof. It samples object
+   * allocations and builds an online 'sampling' heap profile. At any point in
+   * time, this profile is expected to be a representative sample of objects
+   * currently live in the system. Each sampled allocation includes the stack
+   * trace at the time of allocation, which makes this really useful for memory
+   * leak detection.
+   *
+   * This mechanism is intended to be cheap enough that it can be used in
+   * production with minimal performance overhead.
+   *
+   * Allocations are sampled using a randomized Poisson process. On average, one
+   * allocation will be sampled every |sample_interval| bytes allocated. The
+   * |stack_depth| parameter controls the maximum number of stack frames to be
+   * captured on each allocation.
+   *
+   * NOTE: This is a proof-of-concept at this point. Right now we only sample
+   * newspace allocations. Support for paged space allocation (e.g. pre-tenured
+   * objects, large objects, code objects, etc.) and native allocations
+   * doesn't exist yet, but is anticipated in the future.
+   *
+   * Objects allocated before the sampling is started will not be included in
+   * the profile.
+   *
+   * Returns false if a sampling heap profiler is already running.
+   */
+  bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024,
+                                 int stack_depth = 16,
+                                 SamplingFlags flags = kSamplingNoFlags);
+
+  /**
+   * Stops the sampling heap profile and discards the current profile.
+   */
+  void StopSamplingHeapProfiler();
+
+  /**
+   * Returns the sampled profile of allocations allocated (and still live) since
+   * StartSamplingHeapProfiler was called. The ownership of the pointer is
+   * transfered to the caller. Returns nullptr if sampling heap profiler is not
+   * active.
+   */
+  AllocationProfile* GetAllocationProfile();
+
+  /**
+   * Deletes all snapshots taken. All previously returned pointers to
+   * snapshots and their contents become invalid after this call.
+   */
+  void DeleteAllHeapSnapshots();
+
+  /** Binds a callback to embedder's class ID. */
+  void SetWrapperClassInfoProvider(
+      uint16_t class_id,
+      WrapperInfoCallback callback);
+
+  void SetGetRetainerInfosCallback(GetRetainerInfosCallback callback);
+
+  /**
+   * Default value of persistent handle class ID. Must not be used to
+   * define a class. Can be used to reset a class of a persistent
+   * handle.
+   */
+  static const uint16_t kPersistentHandleNoClassId = 0;
+
+  /** Returns memory used for profiler internal data and snapshots. */
+  size_t GetProfilerMemorySize();
+
+ private:
+  HeapProfiler();
+  ~HeapProfiler();
+  HeapProfiler(const HeapProfiler&);
+  HeapProfiler& operator=(const HeapProfiler&);
+};
+
+/**
+ * Interface for providing information about embedder's objects
+ * held by global handles. This information is reported in two ways:
+ *
+ *  1. When calling AddObjectGroup, an embedder may pass
+ *     RetainedObjectInfo instance describing the group.  To collect
+ *     this information while taking a heap snapshot, V8 calls GC
+ *     prologue and epilogue callbacks.
+ *
+ *  2. When a heap snapshot is collected, V8 additionally
+ *     requests RetainedObjectInfos for persistent handles that
+ *     were not previously reported via AddObjectGroup.
+ *
+ * Thus, if an embedder wants to provide information about native
+ * objects for heap snapshots, it can do it in a GC prologue
+ * handler, and / or by assigning wrapper class ids in the following way:
+ *
+ *  1. Bind a callback to class id by calling SetWrapperClassInfoProvider.
+ *  2. Call SetWrapperClassId on certain persistent handles.
+ *
+ * V8 takes ownership of RetainedObjectInfo instances passed to it and
+ * keeps them alive only during snapshot collection. Afterwards, they
+ * are freed by calling the Dispose class function.
+ */
+class V8_EXPORT RetainedObjectInfo {  // NOLINT
+ public:
+  /** Called by V8 when it no longer needs an instance. */
+  virtual void Dispose() = 0;
+
+  /** Returns whether two instances are equivalent. */
+  virtual bool IsEquivalent(RetainedObjectInfo* other) = 0;
+
+  /**
+   * Returns hash value for the instance. Equivalent instances
+   * must have the same hash value.
+   */
+  virtual intptr_t GetHash() = 0;
+
+  /**
+   * Returns human-readable label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetLabel.
+   */
+  virtual const char* GetLabel() = 0;
+
+  /**
+   * Returns human-readable group label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetGroupLabel.
+   * Heap snapshot generator will collect all the group names, create
+   * top level entries with these names and attach the objects to the
+   * corresponding top level group objects. There is a default
+   * implementation which is required because embedders don't have their
+   * own implementation yet.
+   */
+  virtual const char* GetGroupLabel() { return GetLabel(); }
+
+  /**
+   * Returns element count in case if a global handle retains
+   * a subgraph by holding one of its nodes.
+   */
+  virtual intptr_t GetElementCount() { return -1; }
+
+  /** Returns embedder's object size in bytes. */
+  virtual intptr_t GetSizeInBytes() { return -1; }
+
+ protected:
+  RetainedObjectInfo() {}
+  virtual ~RetainedObjectInfo() {}
+
+ private:
+  RetainedObjectInfo(const RetainedObjectInfo&);
+  RetainedObjectInfo& operator=(const RetainedObjectInfo&);
+};
+
+
+/**
+ * A struct for exporting HeapStats data from V8, using "push" model.
+ * See HeapProfiler::GetHeapStats.
+ */
+struct HeapStatsUpdate {
+  HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size)
+    : index(index), count(count), size(size) { }
+  uint32_t index;  // Index of the time interval that was changed.
+  uint32_t count;  // New value of count field for the interval with this index.
+  uint32_t size;  // New value of size field for the interval with this index.
+};
+
+
+}  // namespace v8
+
+
+#endif  // V8_V8_PROFILER_H_
diff --git a/android/armeabi-v7a/include/v8/v8-testing.h b/android/armeabi-v7a/include/v8/v8-testing.h
new file mode 100644
index 00000000..f67bf253
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-testing.h
@@ -0,0 +1,48 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_TEST_H_
+#define V8_V8_TEST_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Testing support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class V8_EXPORT Testing {
+ public:
+  enum StressType {
+    kStressTypeOpt,
+    kStressTypeDeopt
+  };
+
+  /**
+   * Set the type of stressing to do. The default if not set is kStressTypeOpt.
+   */
+  static void SetStressRunType(StressType type);
+
+  /**
+   * Get the number of runs of a given test that is required to get the full
+   * stress coverage.
+   */
+  static int GetStressRuns();
+
+  /**
+   * Indicate the number of the run which is about to start. The value of run
+   * should be between 0 and one less than the result from GetStressRuns()
+   */
+  static void PrepareStressRun(int run);
+
+  /**
+   * Force deoptimization of all functions.
+   */
+  static void DeoptimizeAll(Isolate* isolate);
+};
+
+
+}  // namespace v8
+
+#endif  // V8_V8_TEST_H_
diff --git a/android/armeabi-v7a/include/v8/v8-util.h b/android/armeabi-v7a/include/v8/v8-util.h
new file mode 100644
index 00000000..a04a5e84
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-util.h
@@ -0,0 +1,655 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_UTIL_H_
+#define V8_UTIL_H_
+
+#include "v8.h"  // NOLINT(build/include)
+#include <assert.h>
+#include <map>
+#include <vector>
+
+/**
+ * Support for Persistent containers.
+ *
+ * C++11 embedders can use STL containers with Global values,
+ * but pre-C++11 does not support the required move semantic and hence
+ * may want these container classes.
+ */
+namespace v8 {
+
+typedef uintptr_t PersistentContainerValue;
+static const uintptr_t kPersistentContainerNotFound = 0;
+enum PersistentContainerCallbackType {
+  kNotWeak,
+  // These correspond to v8::WeakCallbackType
+  kWeakWithParameter,
+  kWeakWithInternalFields,
+  kWeak = kWeakWithParameter  // For backwards compatibility.  Deprecate.
+};
+
+
+/**
+ * A default trait implemenation for PersistentValueMap which uses std::map
+ * as a backing map.
+ *
+ * Users will have to implement their own weak callbacks & dispose traits.
+ */
+template<typename K, typename V>
+class StdMapTraits {
+ public:
+  // STL map & related:
+  typedef std::map<K, PersistentContainerValue> Impl;
+  typedef typename Impl::iterator Iterator;
+
+  static bool Empty(Impl* impl) { return impl->empty(); }
+  static size_t Size(Impl* impl) { return impl->size(); }
+  static void Swap(Impl& a, Impl& b) { std::swap(a, b); }  // NOLINT
+  static Iterator Begin(Impl* impl) { return impl->begin(); }
+  static Iterator End(Impl* impl) { return impl->end(); }
+  static K Key(Iterator it) { return it->first; }
+  static PersistentContainerValue Value(Iterator it) { return it->second; }
+  static PersistentContainerValue Set(Impl* impl, K key,
+      PersistentContainerValue value) {
+    std::pair<Iterator, bool> res = impl->insert(std::make_pair(key, value));
+    PersistentContainerValue old_value = kPersistentContainerNotFound;
+    if (!res.second) {
+      old_value = res.first->second;
+      res.first->second = value;
+    }
+    return old_value;
+  }
+  static PersistentContainerValue Get(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    return it->second;
+  }
+  static PersistentContainerValue Remove(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    PersistentContainerValue value = it->second;
+    impl->erase(it);
+    return value;
+  }
+};
+
+
+/**
+ * A default trait implementation for PersistentValueMap, which inherits
+ * a std:map backing map from StdMapTraits and holds non-weak persistent
+ * objects and has no special Dispose handling.
+ *
+ * You should not derive from this class, since MapType depends on the
+ * surrounding class, and hence a subclass cannot simply inherit the methods.
+ */
+template<typename K, typename V>
+class DefaultPersistentValueMapTraits : public StdMapTraits<K, V> {
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef PersistentValueMap<K, V, DefaultPersistentValueMapTraits<K, V> >
+      MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(
+      MapType* map, const K& key, Local<V> value) {
+    return NULL;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return NULL;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) { }
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+};
+
+
+template <typename K, typename V>
+class DefaultGlobalMapTraits : public StdMapTraits<K, V> {
+ private:
+  template <typename T>
+  struct RemovePointer;
+
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef GlobalValueMap<K, V, DefaultGlobalMapTraits<K, V> > MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(MapType* map, const K& key,
+                                                     Local<V> value) {
+    return nullptr;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return nullptr;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) {}
+  static void OnWeakCallback(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+  // This is a second pass callback, so SetSecondPassCallback cannot be called.
+  static void DisposeWeak(const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+
+ private:
+  template <typename T>
+  struct RemovePointer<T*> {
+    typedef T Type;
+  };
+};
+
+
+/**
+ * A map wrapper that allows using Global as a mapped value.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * The map relies on a backing map, whose type and accessors are described
+ * by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template <typename K, typename V, typename Traits>
+class PersistentValueMapBase {
+ public:
+  Isolate* GetIsolate() { return isolate_; }
+
+  /**
+   * Return size of the map.
+   */
+  size_t Size() { return Traits::Size(&impl_); }
+
+  /**
+   * Return whether the map holds weak persistents.
+   */
+  bool IsWeak() { return Traits::kCallbackType != kNotWeak; }
+
+  /**
+   * Get value stored in map.
+   */
+  Local<V> Get(const K& key) {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, key)));
+  }
+
+  /**
+   * Check whether a value is contained in the map.
+   */
+  bool Contains(const K& key) {
+    return Traits::Get(&impl_, key) != kPersistentContainerNotFound;
+  }
+
+  /**
+   * Get value stored in map and set it in returnValue.
+   * Return true if a value was found.
+   */
+  bool SetReturnValue(const K& key,
+      ReturnValue<Value> returnValue) {
+    return SetReturnValueFromVal(&returnValue, Traits::Get(&impl_, key));
+  }
+
+  /**
+   * Call Isolate::SetReference with the given parent and the map value.
+   */
+  void SetReference(const K& key,
+      const Persistent<Object>& parent) {
+    GetIsolate()->SetReference(
+      reinterpret_cast<internal::Object**>(parent.val_),
+      reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))));
+  }
+
+  /**
+   * Call V8::RegisterExternallyReferencedObject with the map value for given
+   * key.
+   */
+  void RegisterExternallyReferencedObject(K& key) {
+    assert(Contains(key));
+    V8::RegisterExternallyReferencedObject(
+        reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))),
+        reinterpret_cast<internal::Isolate*>(GetIsolate()));
+  }
+
+  /**
+   * Return value for key and remove it from the map.
+   */
+  Global<V> Remove(const K& key) {
+    return Release(Traits::Remove(&impl_, key)).Pass();
+  }
+
+  /**
+  * Traverses the map repeatedly,
+  * in case side effects of disposal cause insertions.
+  **/
+  void Clear() {
+    typedef typename Traits::Iterator It;
+    HandleScope handle_scope(isolate_);
+    // TODO(dcarney): figure out if this swap and loop is necessary.
+    while (!Traits::Empty(&impl_)) {
+      typename Traits::Impl impl;
+      Traits::Swap(impl_, impl);
+      for (It i = Traits::Begin(&impl); i != Traits::End(&impl); ++i) {
+        Traits::Dispose(isolate_, Release(Traits::Value(i)).Pass(),
+                        Traits::Key(i));
+      }
+    }
+  }
+
+  /**
+   * Helper class for GetReference/SetWithReference. Do not use outside
+   * that context.
+   */
+  class PersistentValueReference {
+   public:
+    PersistentValueReference() : value_(kPersistentContainerNotFound) { }
+    PersistentValueReference(const PersistentValueReference& other)
+        : value_(other.value_) { }
+
+    Local<V> NewLocal(Isolate* isolate) const {
+      return Local<V>::New(isolate, FromVal(value_));
+    }
+    bool IsEmpty() const {
+      return value_ == kPersistentContainerNotFound;
+    }
+    template<typename T>
+    bool SetReturnValue(ReturnValue<T> returnValue) {
+      return SetReturnValueFromVal(&returnValue, value_);
+    }
+    void Reset() {
+      value_ = kPersistentContainerNotFound;
+    }
+    void operator=(const PersistentValueReference& other) {
+      value_ = other.value_;
+    }
+
+   private:
+    friend class PersistentValueMapBase;
+    friend class PersistentValueMap<K, V, Traits>;
+    friend class GlobalValueMap<K, V, Traits>;
+
+    explicit PersistentValueReference(PersistentContainerValue value)
+        : value_(value) { }
+
+    void operator=(PersistentContainerValue value) {
+      value_ = value;
+    }
+
+    PersistentContainerValue value_;
+  };
+
+  /**
+   * Get a reference to a map value. This enables fast, repeated access
+   * to a value stored in the map while the map remains unchanged.
+   *
+   * Careful: This is potentially unsafe, so please use with care.
+   * The value will become invalid if the value for this key changes
+   * in the underlying map, as a result of Set or Remove for the same
+   * key; as a result of the weak callback for the same key; or as a
+   * result of calling Clear() or destruction of the map.
+   */
+  PersistentValueReference GetReference(const K& key) {
+    return PersistentValueReference(Traits::Get(&impl_, key));
+  }
+
+ protected:
+  explicit PersistentValueMapBase(Isolate* isolate) : isolate_(isolate) {}
+
+  ~PersistentValueMapBase() { Clear(); }
+
+  Isolate* isolate() { return isolate_; }
+  typename Traits::Impl* impl() { return &impl_; }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static PersistentContainerValue Leak(Global<V>* persistent) {
+    return reinterpret_cast<PersistentContainerValue>(persistent->val_);
+  }
+
+  /**
+   * Return a container value as Global and make sure the weak
+   * callback is properly disposed of. All remove functionality should go
+   * through this.
+   */
+  static Global<V> Release(PersistentContainerValue v) {
+    Global<V> p;
+    p.val_ = FromVal(v);
+    if (Traits::kCallbackType != kNotWeak && p.IsWeak()) {
+      Traits::DisposeCallbackData(
+          p.template ClearWeak<typename Traits::WeakCallbackDataType>());
+    }
+    return p.Pass();
+  }
+
+  void RemoveWeak(const K& key) {
+    Global<V> p;
+    p.val_ = FromVal(Traits::Remove(&impl_, key));
+    p.Reset();
+  }
+
+ private:
+  PersistentValueMapBase(PersistentValueMapBase&);
+  void operator=(PersistentValueMapBase&);
+
+  static bool SetReturnValueFromVal(ReturnValue<Value>* returnValue,
+                                    PersistentContainerValue value) {
+    bool hasValue = value != kPersistentContainerNotFound;
+    if (hasValue) {
+      returnValue->SetInternal(
+          *reinterpret_cast<internal::Object**>(FromVal(value)));
+    }
+    return hasValue;
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+
+template <typename K, typename V, typename Traits>
+class PersistentValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit PersistentValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+        Traits::WeakCallbackParameter(this, key, value), WeakCallback);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void WeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      PersistentValueMap<K, V, Traits>* persistentValueMap =
+          Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      Traits::Dispose(data.GetIsolate(),
+                      persistentValueMap->Remove(key).Pass(), key);
+      Traits::DisposeCallbackData(data.GetParameter());
+    }
+  }
+};
+
+
+template <typename K, typename V, typename Traits>
+class GlobalValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit GlobalValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      WeakCallbackType callback_type =
+          Traits::kCallbackType == kWeakWithInternalFields
+              ? WeakCallbackType::kInternalFields
+              : WeakCallbackType::kParameter;
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+          Traits::WeakCallbackParameter(this, key, value), OnWeakCallback,
+          callback_type);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void OnWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      auto map = Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      map->RemoveWeak(key);
+      Traits::OnWeakCallback(data);
+      data.SetSecondPassCallback(SecondWeakCallback);
+    }
+  }
+
+  static void SecondWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    Traits::DisposeWeak(data);
+  }
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Persistents are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template<typename K, typename V,
+    typename Traits = DefaultPersistentValueMapTraits<K, V> >
+class StdPersistentValueMap : public PersistentValueMap<K, V, Traits> {
+ public:
+  explicit StdPersistentValueMap(Isolate* isolate)
+      : PersistentValueMap<K, V, Traits>(isolate) {}
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Globals are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template <typename K, typename V,
+          typename Traits = DefaultGlobalMapTraits<K, V> >
+class StdGlobalValueMap : public GlobalValueMap<K, V, Traits> {
+ public:
+  explicit StdGlobalValueMap(Isolate* isolate)
+      : GlobalValueMap<K, V, Traits>(isolate) {}
+};
+
+
+class DefaultPersistentValueVectorTraits {
+ public:
+  typedef std::vector<PersistentContainerValue> Impl;
+
+  static void Append(Impl* impl, PersistentContainerValue value) {
+    impl->push_back(value);
+  }
+  static bool IsEmpty(const Impl* impl) {
+    return impl->empty();
+  }
+  static size_t Size(const Impl* impl) {
+    return impl->size();
+  }
+  static PersistentContainerValue Get(const Impl* impl, size_t i) {
+    return (i < impl->size()) ? impl->at(i) : kPersistentContainerNotFound;
+  }
+  static void ReserveCapacity(Impl* impl, size_t capacity) {
+    impl->reserve(capacity);
+  }
+  static void Clear(Impl* impl) {
+    impl->clear();
+  }
+};
+
+
+/**
+ * A vector wrapper that safely stores Global values.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * This class relies on a backing vector implementation, whose type and methods
+ * are described by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template<typename V, typename Traits = DefaultPersistentValueVectorTraits>
+class PersistentValueVector {
+ public:
+  explicit PersistentValueVector(Isolate* isolate) : isolate_(isolate) { }
+
+  ~PersistentValueVector() {
+    Clear();
+  }
+
+  /**
+   * Append a value to the vector.
+   */
+  void Append(Local<V> value) {
+    Global<V> persistent(isolate_, value);
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Append a persistent's value to the vector.
+   */
+  void Append(Global<V> persistent) {
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Are there any values in the vector?
+   */
+  bool IsEmpty() const {
+    return Traits::IsEmpty(&impl_);
+  }
+
+  /**
+   * How many elements are in the vector?
+   */
+  size_t Size() const {
+    return Traits::Size(&impl_);
+  }
+
+  /**
+   * Retrieve the i-th value in the vector.
+   */
+  Local<V> Get(size_t index) const {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, index)));
+  }
+
+  /**
+   * Remove all elements from the vector.
+   */
+  void Clear() {
+    size_t length = Traits::Size(&impl_);
+    for (size_t i = 0; i < length; i++) {
+      Global<V> p;
+      p.val_ = FromVal(Traits::Get(&impl_, i));
+    }
+    Traits::Clear(&impl_);
+  }
+
+  /**
+   * Reserve capacity in the vector.
+   * (Efficiency gains depend on the backing implementation.)
+   */
+  void ReserveCapacity(size_t capacity) {
+    Traits::ReserveCapacity(&impl_, capacity);
+  }
+
+ private:
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+}  // namespace v8
+
+#endif  // V8_UTIL_H
diff --git a/android/armeabi-v7a/include/v8/v8-value-serializer-version.h b/android/armeabi-v7a/include/v8/v8-value-serializer-version.h
new file mode 100644
index 00000000..c72911c6
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-value-serializer-version.h
@@ -0,0 +1,24 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Compile-time constants.
+ *
+ * This header provides access to information about the value serializer at
+ * compile time, without declaring or defining any symbols that require linking
+ * to V8.
+ */
+
+#ifndef INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+#define INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+
+#include <stdint.h>
+
+namespace v8 {
+
+constexpr uint32_t CurrentValueSerializerFormatVersion() { return 13; }
+
+}  // namespace v8
+
+#endif  // INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
diff --git a/android/armeabi-v7a/include/v8/v8-version-string.h b/android/armeabi-v7a/include/v8/v8-version-string.h
new file mode 100644
index 00000000..075282de
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-version-string.h
@@ -0,0 +1,33 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_VERSION_STRING_H_
+#define V8_VERSION_STRING_H_
+
+#include "v8-version.h"  // NOLINT(build/include)
+
+// This is here rather than v8-version.h to keep that file simple and
+// machine-processable.
+
+#if V8_IS_CANDIDATE_VERSION
+#define V8_CANDIDATE_STRING " (candidate)"
+#else
+#define V8_CANDIDATE_STRING ""
+#endif
+
+#define V8_SX(x) #x
+#define V8_S(x) V8_SX(x)
+
+#if V8_PATCH_LEVEL > 0
+#define V8_VERSION_STRING                                        \
+  V8_S(V8_MAJOR_VERSION)                                         \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) "." V8_S( \
+      V8_PATCH_LEVEL) V8_CANDIDATE_STRING
+#else
+#define V8_VERSION_STRING \
+  V8_S(V8_MAJOR_VERSION)  \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) V8_CANDIDATE_STRING
+#endif
+
+#endif  // V8_VERSION_STRING_H_
diff --git a/android/armeabi-v7a/include/v8/v8-version.h b/android/armeabi-v7a/include/v8/v8-version.h
new file mode 100644
index 00000000..0889459c
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8-version.h
@@ -0,0 +1,20 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INCLUDE_VERSION_H_  // V8_VERSION_H_ conflicts with src/version.h
+#define V8_INCLUDE_VERSION_H_
+
+// These macros define the version number for the current version.
+// NOTE these macros are used by some of the tool scripts and the build
+// system so their names cannot be changed without changing the scripts.
+#define V8_MAJOR_VERSION 6
+#define V8_MINOR_VERSION 0
+#define V8_BUILD_NUMBER 286
+#define V8_PATCH_LEVEL 52
+
+// Use 1 for candidates and 0 otherwise.
+// (Boolean macro values are not supported by all preprocessors.)
+#define V8_IS_CANDIDATE_VERSION 0
+
+#endif  // V8_INCLUDE_VERSION_H_
diff --git a/android/armeabi-v7a/include/v8/v8.h b/android/armeabi-v7a/include/v8/v8.h
new file mode 100644
index 00000000..da3cdfdc
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8.h
@@ -0,0 +1,10155 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/** \mainpage V8 API Reference Guide
+ *
+ * V8 is Google's open source JavaScript engine.
+ *
+ * This set of documents provides reference material generated from the
+ * V8 header file, include/v8.h.
+ *
+ * For other documentation see http://code.google.com/apis/v8/
+ */
+
+#ifndef INCLUDE_V8_H_
+#define INCLUDE_V8_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "v8-version.h"  // NOLINT(build/include)
+#include "v8config.h"    // NOLINT(build/include)
+
+// We reserve the V8_* prefix for macros defined in V8 public API and
+// assume there are no name conflicts with the embedder's code.
+
+#ifdef V8_OS_WIN
+
+// Setup for Windows DLL export/import. When building the V8 DLL the
+// BUILDING_V8_SHARED needs to be defined. When building a program which uses
+// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
+// static library or building a program which uses the V8 static library neither
+// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
+#ifdef BUILDING_V8_SHARED
+# define V8_EXPORT __declspec(dllexport)
+#elif USING_V8_SHARED
+# define V8_EXPORT __declspec(dllimport)
+#else
+# define V8_EXPORT
+#endif  // BUILDING_V8_SHARED
+
+#else  // V8_OS_WIN
+
+// Setup for Linux shared library export.
+#if V8_HAS_ATTRIBUTE_VISIBILITY
+# ifdef BUILDING_V8_SHARED
+#  define V8_EXPORT __attribute__ ((visibility("default")))
+# else
+#  define V8_EXPORT
+# endif
+#else
+# define V8_EXPORT
+#endif
+
+#endif  // V8_OS_WIN
+
+/**
+ * The v8 JavaScript engine.
+ */
+namespace v8 {
+
+class AccessorSignature;
+class Array;
+class ArrayBuffer;
+class Boolean;
+class BooleanObject;
+class Context;
+class CpuProfiler;
+class Data;
+class Date;
+class External;
+class Function;
+class FunctionTemplate;
+class HeapProfiler;
+class ImplementationUtilities;
+class Int32;
+class Integer;
+class Isolate;
+template <class T>
+class Maybe;
+class Name;
+class Number;
+class NumberObject;
+class Object;
+class ObjectOperationDescriptor;
+class ObjectTemplate;
+class Platform;
+class Primitive;
+class Promise;
+class PropertyDescriptor;
+class Proxy;
+class RawOperationDescriptor;
+class Script;
+class SharedArrayBuffer;
+class Signature;
+class StartupData;
+class StackFrame;
+class StackTrace;
+class String;
+class StringObject;
+class Symbol;
+class SymbolObject;
+class Private;
+class Uint32;
+class Utils;
+class Value;
+class WasmCompiledModule;
+template <class T> class Local;
+template <class T>
+class MaybeLocal;
+template <class T> class Eternal;
+template<class T> class NonCopyablePersistentTraits;
+template<class T> class PersistentBase;
+template <class T, class M = NonCopyablePersistentTraits<T> >
+class Persistent;
+template <class T>
+class Global;
+template<class K, class V, class T> class PersistentValueMap;
+template <class K, class V, class T>
+class PersistentValueMapBase;
+template <class K, class V, class T>
+class GlobalValueMap;
+template<class V, class T> class PersistentValueVector;
+template<class T, class P> class WeakCallbackObject;
+class FunctionTemplate;
+class ObjectTemplate;
+template<typename T> class FunctionCallbackInfo;
+template<typename T> class PropertyCallbackInfo;
+class StackTrace;
+class StackFrame;
+class Isolate;
+class CallHandlerHelper;
+class EscapableHandleScope;
+template<typename T> class ReturnValue;
+
+namespace internal {
+class Arguments;
+class Heap;
+class HeapObject;
+class Isolate;
+class Object;
+struct StreamedSource;
+template<typename T> class CustomArguments;
+class PropertyCallbackArguments;
+class FunctionCallbackArguments;
+class GlobalHandles;
+}  // namespace internal
+
+namespace debug {
+class ConsoleCallArguments;
+}  // namespace debug
+
+// --- Handles ---
+
+#define TYPE_CHECK(T, S)                                       \
+  while (false) {                                              \
+    *(static_cast<T* volatile*>(0)) = static_cast<S*>(0);      \
+  }
+
+/**
+ * An object reference managed by the v8 garbage collector.
+ *
+ * All objects returned from v8 have to be tracked by the garbage
+ * collector so that it knows that the objects are still alive.  Also,
+ * because the garbage collector may move objects, it is unsafe to
+ * point directly to an object.  Instead, all objects are stored in
+ * handles which are known by the garbage collector and updated
+ * whenever an object moves.  Handles should always be passed by value
+ * (except in cases like out-parameters) and they should never be
+ * allocated on the heap.
+ *
+ * There are two types of handles: local and persistent handles.
+ *
+ * Local handles are light-weight and transient and typically used in
+ * local operations.  They are managed by HandleScopes. That means that a
+ * HandleScope must exist on the stack when they are created and that they are
+ * only valid inside of the HandleScope active during their creation.
+ * For passing a local handle to an outer HandleScope, an EscapableHandleScope
+ * and its Escape() method must be used.
+ *
+ * Persistent handles can be used when storing objects across several
+ * independent operations and have to be explicitly deallocated when they're no
+ * longer used.
+ *
+ * It is safe to extract the object stored in the handle by
+ * dereferencing the handle (for instance, to extract the Object* from
+ * a Local<Object>); the value will still be governed by a handle
+ * behind the scenes and the same rules apply to these values as to
+ * their handles.
+ */
+template <class T>
+class Local {
+ public:
+  V8_INLINE Local() : val_(0) {}
+  template <class S>
+  V8_INLINE Local(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    /**
+     * This check fails when trying to convert between incompatible
+     * handles. For example, converting from a Local<String> to a
+     * Local<Number>.
+     */
+    TYPE_CHECK(T, S);
+  }
+
+  /**
+   * Returns true if the handle is empty.
+   */
+  V8_INLINE bool IsEmpty() const { return val_ == 0; }
+
+  /**
+   * Sets the handle to be empty. IsEmpty() will then return true.
+   */
+  V8_INLINE void Clear() { val_ = 0; }
+
+  V8_INLINE T* operator->() const { return val_; }
+
+  V8_INLINE T* operator*() const { return val_; }
+
+  /**
+   * Checks whether two handles are the same.
+   * Returns true if both are empty, or if the objects
+   * to which they refer are identical.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  template <class S> V8_INLINE bool operator==(
+      const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  /**
+   * Checks whether two handles are different.
+   * Returns true if only one of the handles is empty, or if
+   * the objects to which they refer are different.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S> V8_INLINE bool operator!=(
+      const Persistent<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   * Cast a handle to a subclass, e.g. Local<Value> to Local<Object>.
+   * This is only valid if the handle actually refers to a value of the
+   * target type.
+   */
+  template <class S> V8_INLINE static Local<T> Cast(Local<S> that) {
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (that.IsEmpty()) return Local<T>();
+#endif
+    return Local<T>(T::Cast(*that));
+  }
+
+  /**
+   * Calling this is equivalent to Local<S>::Cast().
+   * In particular, this is only valid if the handle actually refers to a value
+   * of the target type.
+   */
+  template <class S>
+  V8_INLINE Local<S> As() const {
+    return Local<S>::Cast(*this);
+  }
+
+  /**
+   * Create a local handle for the content of another handle.
+   * The referee is kept alive by the local handle even when
+   * the original handle is destroyed/disposed.
+   */
+  V8_INLINE static Local<T> New(Isolate* isolate, Local<T> that);
+  V8_INLINE static Local<T> New(Isolate* isolate,
+                                const PersistentBase<T>& that);
+
+ private:
+  friend class Utils;
+  template<class F> friend class Eternal;
+  template<class F> friend class PersistentBase;
+  template<class F, class M> friend class Persistent;
+  template<class F> friend class Local;
+  template <class F>
+  friend class MaybeLocal;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  friend class String;
+  friend class Object;
+  friend class Context;
+  friend class Private;
+  template<class F> friend class internal::CustomArguments;
+  friend Local<Primitive> Undefined(Isolate* isolate);
+  friend Local<Primitive> Null(Isolate* isolate);
+  friend Local<Boolean> True(Isolate* isolate);
+  friend Local<Boolean> False(Isolate* isolate);
+  friend class HandleScope;
+  friend class EscapableHandleScope;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  template <class F>
+  friend class ReturnValue;
+
+  explicit V8_INLINE Local(T* that) : val_(that) {}
+  V8_INLINE static Local<T> New(Isolate* isolate, T* that);
+  T* val_;
+};
+
+
+#if !defined(V8_IMMINENT_DEPRECATION_WARNINGS)
+// Handle is an alias for Local for historical reasons.
+template <class T>
+using Handle = Local<T>;
+#endif
+
+
+/**
+ * A MaybeLocal<> is a wrapper around Local<> that enforces a check whether
+ * the Local<> is empty before it can be used.
+ *
+ * If an API method returns a MaybeLocal<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, an
+ * empty MaybeLocal is returned.
+ */
+template <class T>
+class MaybeLocal {
+ public:
+  V8_INLINE MaybeLocal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE MaybeLocal(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    TYPE_CHECK(T, S);
+  }
+
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * |false| is returned and |out| is left untouched.
+   */
+  template <class S>
+  V8_WARN_UNUSED_RESULT V8_INLINE bool ToLocal(Local<S>* out) const {
+    out->val_ = IsEmpty() ? nullptr : this->val_;
+    return !IsEmpty();
+  }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * V8 will crash the process.
+   */
+  V8_INLINE Local<T> ToLocalChecked();
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>, using a default value if this
+   * MaybeLocal<> is empty.
+   */
+  template <class S>
+  V8_INLINE Local<S> FromMaybe(Local<S> default_value) const {
+    return IsEmpty() ? default_value : Local<S>(val_);
+  }
+
+ private:
+  T* val_;
+};
+
+/**
+ * Eternal handles are set-once handles that live for the lifetime of the
+ * isolate.
+ */
+template <class T> class Eternal {
+ public:
+  V8_INLINE Eternal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE Eternal(Isolate* isolate, Local<S> handle) : val_(nullptr) {
+    Set(isolate, handle);
+  }
+  // Can only be safely called if already set.
+  V8_INLINE Local<T> Get(Isolate* isolate) const;
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+  template<class S> V8_INLINE void Set(Isolate* isolate, Local<S> handle);
+
+ private:
+  T* val_;
+};
+
+
+static const int kInternalFieldsInWeakCallback = 2;
+static const int kEmbedderFieldsInWeakCallback = 2;
+
+template <typename T>
+class WeakCallbackInfo {
+ public:
+  typedef void (*Callback)(const WeakCallbackInfo<T>& data);
+
+  WeakCallbackInfo(Isolate* isolate, T* parameter,
+                   void* embedder_fields[kEmbedderFieldsInWeakCallback],
+                   Callback* callback)
+      : isolate_(isolate), parameter_(parameter), callback_(callback) {
+    for (int i = 0; i < kEmbedderFieldsInWeakCallback; ++i) {
+      embedder_fields_[i] = embedder_fields[i];
+    }
+  }
+
+  V8_INLINE Isolate* GetIsolate() const { return isolate_; }
+  V8_INLINE T* GetParameter() const { return parameter_; }
+  V8_INLINE void* GetInternalField(int index) const;
+
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField1() const) {
+    return embedder_fields_[0];
+  }
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField2() const) {
+    return embedder_fields_[1];
+  }
+
+  V8_DEPRECATED("Not realiable once SetSecondPassCallback() was used.",
+                bool IsFirstPass() const) {
+    return callback_ != nullptr;
+  }
+
+  // When first called, the embedder MUST Reset() the Global which triggered the
+  // callback. The Global itself is unusable for anything else. No v8 other api
+  // calls may be called in the first callback. Should additional work be
+  // required, the embedder must set a second pass callback, which will be
+  // called after all the initial callbacks are processed.
+  // Calling SetSecondPassCallback on the second pass will immediately crash.
+  void SetSecondPassCallback(Callback callback) const { *callback_ = callback; }
+
+ private:
+  Isolate* isolate_;
+  T* parameter_;
+  Callback* callback_;
+  void* embedder_fields_[kEmbedderFieldsInWeakCallback];
+};
+
+
+// kParameter will pass a void* parameter back to the callback, kInternalFields
+// will pass the first two internal fields back to the callback, kFinalizer
+// will pass a void* parameter back, but is invoked before the object is
+// actually collected, so it can be resurrected. In the last case, it is not
+// possible to request a second pass callback.
+enum class WeakCallbackType { kParameter, kInternalFields, kFinalizer };
+
+/**
+ * An object reference that is independent of any handle scope.  Where
+ * a Local handle only lives as long as the HandleScope in which it was
+ * allocated, a PersistentBase handle remains valid until it is explicitly
+ * disposed using Reset().
+ *
+ * A persistent handle contains a reference to a storage cell within
+ * the V8 engine which holds an object value and which is updated by
+ * the garbage collector whenever the object is moved.  A new storage
+ * cell can be created using the constructor or PersistentBase::Reset and
+ * existing handles can be disposed using PersistentBase::Reset.
+ *
+ */
+template <class T> class PersistentBase {
+ public:
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * IsEmpty() will return true after this call.
+   */
+  V8_INLINE void Reset();
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const Local<S>& other);
+
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const PersistentBase<S>& other);
+
+  V8_INLINE bool IsEmpty() const { return val_ == NULL; }
+  V8_INLINE void Empty() { val_ = 0; }
+
+  V8_INLINE Local<T> Get(Isolate* isolate) const {
+    return Local<T>::New(isolate, *this);
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const PersistentBase<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   *  Install a finalization callback on this object.
+   *  NOTE: There is no guarantee as to *when* or even *if* the callback is
+   *  invoked. The invocation is performed solely on a best effort basis.
+   *  As always, GC-based finalization should *not* be relied upon for any
+   *  critical form of resource management!
+   */
+  template <typename P>
+  V8_INLINE void SetWeak(P* parameter,
+                         typename WeakCallbackInfo<P>::Callback callback,
+                         WeakCallbackType type);
+
+  /**
+   * Turns this handle into a weak phantom handle without finalization callback.
+   * The handle will be reset automatically when the garbage collector detects
+   * that the object is no longer reachable.
+   * A related function Isolate::NumberOfPhantomHandleResetsSinceLastCall
+   * returns how many phantom handles were reset by the garbage collector.
+   */
+  V8_INLINE void SetWeak();
+
+  template<typename P>
+  V8_INLINE P* ClearWeak();
+
+  // TODO(dcarney): remove this.
+  V8_INLINE void ClearWeak() { ClearWeak<void>(); }
+
+  /**
+   * Allows the embedder to tell the v8 garbage collector that a certain object
+   * is alive. Only allowed when the embedder is asked to trace its heap by
+   * EmbedderHeapTracer.
+   */
+  V8_INLINE void RegisterExternalReference(Isolate* isolate) const;
+
+  /**
+   * Marks the reference to this object independent. Garbage collector is free
+   * to ignore any object groups containing this object. Weak callback for an
+   * independent handle should not assume that it will be preceded by a global
+   * GC prologue callback or followed by a global GC epilogue callback.
+   */
+  V8_INLINE void MarkIndependent();
+
+  /**
+   * Marks the reference to this object as active. The scavenge garbage
+   * collection should not reclaim the objects marked as active.
+   * This bit is cleared after the each garbage collection pass.
+   */
+  V8_INLINE void MarkActive();
+
+  V8_INLINE bool IsIndependent() const;
+
+  /** Checks if the handle holds the only reference to an object. */
+  V8_INLINE bool IsNearDeath() const;
+
+  /** Returns true if the handle's reference is weak.  */
+  V8_INLINE bool IsWeak() const;
+
+  /**
+   * Assigns a wrapper class ID to the handle. See RetainedObjectInfo interface
+   * description in v8-profiler.h for details.
+   */
+  V8_INLINE void SetWrapperClassId(uint16_t class_id);
+
+  /**
+   * Returns the class ID previously assigned to this handle or 0 if no class ID
+   * was previously assigned.
+   */
+  V8_INLINE uint16_t WrapperClassId() const;
+
+  PersistentBase(const PersistentBase& other) = delete;  // NOLINT
+  void operator=(const PersistentBase&) = delete;
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template <class F>
+  friend class Global;
+  template<class F> friend class PersistentBase;
+  template<class F> friend class ReturnValue;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  friend class Object;
+
+  explicit V8_INLINE PersistentBase(T* val) : val_(val) {}
+  V8_INLINE static T* New(Isolate* isolate, T* that);
+
+  T* val_;
+};
+
+
+/**
+ * Default traits for Persistent. This class does not allow
+ * use of the copy constructor or assignment operator.
+ * At present kResetInDestructor is not set, but that will change in a future
+ * version.
+ */
+template<class T>
+class NonCopyablePersistentTraits {
+ public:
+  typedef Persistent<T, NonCopyablePersistentTraits<T> > NonCopyablePersistent;
+  static const bool kResetInDestructor = false;
+  template<class S, class M>
+  V8_INLINE static void Copy(const Persistent<S, M>& source,
+                             NonCopyablePersistent* dest) {
+    Uncompilable<Object>();
+  }
+  // TODO(dcarney): come up with a good compile error here.
+  template<class O> V8_INLINE static void Uncompilable() {
+    TYPE_CHECK(O, Primitive);
+  }
+};
+
+
+/**
+ * Helper class traits to allow copying and assignment of Persistent.
+ * This will clone the contents of storage cell, but not any of the flags, etc.
+ */
+template<class T>
+struct CopyablePersistentTraits {
+  typedef Persistent<T, CopyablePersistentTraits<T> > CopyablePersistent;
+  static const bool kResetInDestructor = true;
+  template<class S, class M>
+  static V8_INLINE void Copy(const Persistent<S, M>& source,
+                             CopyablePersistent* dest) {
+    // do nothing, just allow copy
+  }
+};
+
+
+/**
+ * A PersistentBase which allows copy and assignment.
+ *
+ * Copy, assignment and destructor behavior is controlled by the traits
+ * class M.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T, class M> class Persistent : public PersistentBase<T> {
+ public:
+  /**
+   * A Persistent with no storage cell.
+   */
+  V8_INLINE Persistent() : PersistentBase<T>(0) { }
+  /**
+   * Construct a Persistent from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Persistent(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Persistent from a Persistent.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S, class M2>
+  V8_INLINE Persistent(Isolate* isolate, const Persistent<S, M2>& that)
+    : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * The copy constructors and assignment operator create a Persistent
+   * exactly as the Persistent constructor, but the Copy function from the
+   * traits class is called, allowing the setting of flags based on the
+   * copied Persistent.
+   */
+  V8_INLINE Persistent(const Persistent& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent(const Persistent<S, M2>& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  V8_INLINE Persistent& operator=(const Persistent& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent& operator=(const Persistent<S, M2>& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  /**
+   * The destructor will dispose the Persistent based on the
+   * kResetInDestructor flags in the traits class.  Since not calling dispose
+   * can result in a memory leak, it is recommended to always set this flag.
+   */
+  V8_INLINE ~Persistent() {
+    if (M::kResetInDestructor) this->Reset();
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE static Persistent<T>& Cast(const Persistent<S>& that) {  // NOLINT
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (!that.IsEmpty()) T::Cast(*that);
+#endif
+    return reinterpret_cast<Persistent<T>&>(const_cast<Persistent<S>&>(that));
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE Persistent<S>& As() const {  // NOLINT
+    return Persistent<S>::Cast(*this);
+  }
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template<class F> friend class ReturnValue;
+
+  explicit V8_INLINE Persistent(T* that) : PersistentBase<T>(that) {}
+  V8_INLINE T* operator*() const { return this->val_; }
+  template<class S, class M2>
+  V8_INLINE void Copy(const Persistent<S, M2>& that);
+};
+
+
+/**
+ * A PersistentBase which has move semantics.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T>
+class Global : public PersistentBase<T> {
+ public:
+  /**
+   * A Global with no storage cell.
+   */
+  V8_INLINE Global() : PersistentBase<T>(nullptr) {}
+  /**
+   * Construct a Global from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Global from a PersistentBase.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, const PersistentBase<S>& that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, that.val_)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Move constructor.
+   */
+  V8_INLINE Global(Global&& other) : PersistentBase<T>(other.val_) {  // NOLINT
+    other.val_ = nullptr;
+  }
+  V8_INLINE ~Global() { this->Reset(); }
+  /**
+   * Move via assignment.
+   */
+  template <class S>
+  V8_INLINE Global& operator=(Global<S>&& rhs) {  // NOLINT
+    TYPE_CHECK(T, S);
+    if (this != &rhs) {
+      this->Reset();
+      this->val_ = rhs.val_;
+      rhs.val_ = nullptr;
+    }
+    return *this;
+  }
+  /**
+   * Pass allows returning uniques from functions, etc.
+   */
+  Global Pass() { return static_cast<Global&&>(*this); }  // NOLINT
+
+  /*
+   * For compatibility with Chromium's base::Bind (base::Passed).
+   */
+  typedef void MoveOnlyTypeForCPP03;
+
+  Global(const Global&) = delete;
+  void operator=(const Global&) = delete;
+
+ private:
+  template <class F>
+  friend class ReturnValue;
+  V8_INLINE T* operator*() const { return this->val_; }
+};
+
+
+// UniquePersistent is an alias for Global for historical reason.
+template <class T>
+using UniquePersistent = Global<T>;
+
+
+ /**
+ * A stack-allocated class that governs a number of local handles.
+ * After a handle scope has been created, all local handles will be
+ * allocated within that handle scope until either the handle scope is
+ * deleted or another handle scope is created.  If there is already a
+ * handle scope and a new one is created, all allocations will take
+ * place in the new handle scope until it is deleted.  After that,
+ * new handles will again be allocated in the original handle scope.
+ *
+ * After the handle scope of a local handle has been deleted the
+ * garbage collector will no longer track the object stored in the
+ * handle and may deallocate it.  The behavior of accessing a handle
+ * for which the handle scope has been deleted is undefined.
+ */
+class V8_EXPORT HandleScope {
+ public:
+  explicit HandleScope(Isolate* isolate);
+
+  ~HandleScope();
+
+  /**
+   * Counts the number of allocated handles.
+   */
+  static int NumberOfHandles(Isolate* isolate);
+
+  V8_INLINE Isolate* GetIsolate() const {
+    return reinterpret_cast<Isolate*>(isolate_);
+  }
+
+  HandleScope(const HandleScope&) = delete;
+  void operator=(const HandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ protected:
+  V8_INLINE HandleScope() {}
+
+  void Initialize(Isolate* isolate);
+
+  static internal::Object** CreateHandle(internal::Isolate* isolate,
+                                         internal::Object* value);
+
+ private:
+  // Uses heap_object to obtain the current Isolate.
+  static internal::Object** CreateHandle(internal::HeapObject* heap_object,
+                                         internal::Object* value);
+
+  internal::Isolate* isolate_;
+  internal::Object** prev_next_;
+  internal::Object** prev_limit_;
+
+  // Local::New uses CreateHandle with an Isolate* parameter.
+  template<class F> friend class Local;
+
+  // Object::GetInternalField and Context::GetEmbedderData use CreateHandle with
+  // a HeapObject* in their shortcuts.
+  friend class Object;
+  friend class Context;
+};
+
+
+/**
+ * A HandleScope which first allocates a handle in the current scope
+ * which will be later filled with the escape value.
+ */
+class V8_EXPORT EscapableHandleScope : public HandleScope {
+ public:
+  explicit EscapableHandleScope(Isolate* isolate);
+  V8_INLINE ~EscapableHandleScope() {}
+
+  /**
+   * Pushes the value into the previous scope and returns a handle to it.
+   * Cannot be called twice.
+   */
+  template <class T>
+  V8_INLINE Local<T> Escape(Local<T> value) {
+    internal::Object** slot =
+        Escape(reinterpret_cast<internal::Object**>(*value));
+    return Local<T>(reinterpret_cast<T*>(slot));
+  }
+
+  EscapableHandleScope(const EscapableHandleScope&) = delete;
+  void operator=(const EscapableHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Object** Escape(internal::Object** escape_value);
+  internal::Object** escape_slot_;
+};
+
+/**
+ * A SealHandleScope acts like a handle scope in which no handle allocations
+ * are allowed. It can be useful for debugging handle leaks.
+ * Handles can be allocated within inner normal HandleScopes.
+ */
+class V8_EXPORT SealHandleScope {
+ public:
+  SealHandleScope(Isolate* isolate);
+  ~SealHandleScope();
+
+  SealHandleScope(const SealHandleScope&) = delete;
+  void operator=(const SealHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Isolate* const isolate_;
+  internal::Object** prev_limit_;
+  int prev_sealed_level_;
+};
+
+
+// --- Special objects ---
+
+
+/**
+ * The superclass of values and API object templates.
+ */
+class V8_EXPORT Data {
+ private:
+  Data();
+};
+
+
+/**
+ * The optional attributes of ScriptOrigin.
+ */
+class ScriptOriginOptions {
+ public:
+  V8_INLINE ScriptOriginOptions(bool is_shared_cross_origin = false,
+                                bool is_opaque = false, bool is_wasm = false,
+                                bool is_module = false)
+      : flags_((is_shared_cross_origin ? kIsSharedCrossOrigin : 0) |
+               (is_wasm ? kIsWasm : 0) | (is_opaque ? kIsOpaque : 0) |
+               (is_module ? kIsModule : 0)) {}
+  V8_INLINE ScriptOriginOptions(int flags)
+      : flags_(flags &
+               (kIsSharedCrossOrigin | kIsOpaque | kIsWasm | kIsModule)) {}
+
+  bool IsSharedCrossOrigin() const {
+    return (flags_ & kIsSharedCrossOrigin) != 0;
+  }
+  bool IsOpaque() const { return (flags_ & kIsOpaque) != 0; }
+  bool IsWasm() const { return (flags_ & kIsWasm) != 0; }
+  bool IsModule() const { return (flags_ & kIsModule) != 0; }
+
+  int Flags() const { return flags_; }
+
+ private:
+  enum {
+    kIsSharedCrossOrigin = 1,
+    kIsOpaque = 1 << 1,
+    kIsWasm = 1 << 2,
+    kIsModule = 1 << 3
+  };
+  const int flags_;
+};
+
+/**
+ * The origin, within a file, of a script.
+ */
+class ScriptOrigin {
+ public:
+  V8_INLINE ScriptOrigin(
+      Local<Value> resource_name,
+      Local<Integer> resource_line_offset = Local<Integer>(),
+      Local<Integer> resource_column_offset = Local<Integer>(),
+      Local<Boolean> resource_is_shared_cross_origin = Local<Boolean>(),
+      Local<Integer> script_id = Local<Integer>(),
+      Local<Value> source_map_url = Local<Value>(),
+      Local<Boolean> resource_is_opaque = Local<Boolean>(),
+      Local<Boolean> is_wasm = Local<Boolean>(),
+      Local<Boolean> is_module = Local<Boolean>());
+
+  V8_INLINE Local<Value> ResourceName() const;
+  V8_INLINE Local<Integer> ResourceLineOffset() const;
+  V8_INLINE Local<Integer> ResourceColumnOffset() const;
+  /**
+    * Returns true for embedder's debugger scripts
+    */
+  V8_INLINE Local<Integer> ScriptID() const;
+  V8_INLINE Local<Value> SourceMapUrl() const;
+  V8_INLINE ScriptOriginOptions Options() const { return options_; }
+
+ private:
+  Local<Value> resource_name_;
+  Local<Integer> resource_line_offset_;
+  Local<Integer> resource_column_offset_;
+  ScriptOriginOptions options_;
+  Local<Integer> script_id_;
+  Local<Value> source_map_url_;
+};
+
+
+/**
+ * A compiled JavaScript script, not yet tied to a Context.
+ */
+class V8_EXPORT UnboundScript {
+ public:
+  /**
+   * Binds the script to the currently entered context.
+   */
+  Local<Script> BindToCurrentContext();
+
+  int GetId();
+  Local<Value> GetScriptName();
+
+  /**
+   * Data read from magic sourceURL comments.
+   */
+  Local<Value> GetSourceURL();
+  /**
+   * Data read from magic sourceMappingURL comments.
+   */
+  Local<Value> GetSourceMappingURL();
+
+  /**
+   * Returns zero based line number of the code_pos location in the script.
+   * -1 will be returned if no information available.
+   */
+  int GetLineNumber(int code_pos);
+
+  static const int kNoScriptId = 0;
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT Module {
+ public:
+  /**
+   * Returns the number of modules requested by this module.
+   */
+  int GetModuleRequestsLength() const;
+
+  /**
+   * Returns the ith module specifier in this module.
+   * i must be < GetModuleRequestsLength() and >= 0.
+   */
+  Local<String> GetModuleRequest(int i) const;
+
+  /**
+   * Returns the identity hash for this object.
+   */
+  int GetIdentityHash() const;
+
+  typedef MaybeLocal<Module> (*ResolveCallback)(Local<Context> context,
+                                                Local<String> specifier,
+                                                Local<Module> referrer);
+
+  /**
+   * ModuleDeclarationInstantiation
+   *
+   * Returns false if an exception occurred during instantiation. (In the case
+   * where the callback throws an exception, that exception is propagated.)
+   */
+  V8_WARN_UNUSED_RESULT bool Instantiate(Local<Context> context,
+                                         ResolveCallback callback);
+
+  /**
+   * ModuleEvaluation
+   *
+   * Returns the completion value.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Evaluate(Local<Context> context);
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT DynamicImportResult {
+ public:
+  /**
+   * Resolves the promise with the namespace object of the given
+   * module.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportSuccess(Local<Context> context,
+                                                        Local<Module> module);
+
+  /**
+   * Rejects the promise with the given exception.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportFailure(Local<Context> context,
+                                                        Local<Value> exception);
+};
+
+/**
+ * A compiled JavaScript script, tied to a Context which was active when the
+ * script was compiled.
+ */
+class V8_EXPORT Script {
+ public:
+  /**
+   * A shorthand for ScriptCompiler::Compile().
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Script> Compile(Local<String> source,
+                            ScriptOrigin* origin = nullptr));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Local<String> source,
+      ScriptOrigin* origin = nullptr);
+
+  static Local<Script> V8_DEPRECATE_SOON("Use maybe version",
+                                         Compile(Local<String> source,
+                                                 Local<String> file_name));
+
+  /**
+   * Runs the script returning the resulting value. It will be run in the
+   * context in which it was created (ScriptCompiler::CompileBound or
+   * UnboundScript::BindToCurrentContext()).
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Run());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Run(Local<Context> context);
+
+  /**
+   * Returns the corresponding context-unbound script.
+   */
+  Local<UnboundScript> GetUnboundScript();
+};
+
+
+/**
+ * For compiling scripts.
+ */
+class V8_EXPORT ScriptCompiler {
+ public:
+  /**
+   * Compilation data that the embedder can cache and pass back to speed up
+   * future compilations. The data is produced if the CompilerOptions passed to
+   * the compilation functions in ScriptCompiler contains produce_data_to_cache
+   * = true. The data to cache can then can be retrieved from
+   * UnboundScript.
+   */
+  struct V8_EXPORT CachedData {
+    enum BufferPolicy {
+      BufferNotOwned,
+      BufferOwned
+    };
+
+    CachedData()
+        : data(NULL),
+          length(0),
+          rejected(false),
+          buffer_policy(BufferNotOwned) {}
+
+    // If buffer_policy is BufferNotOwned, the caller keeps the ownership of
+    // data and guarantees that it stays alive until the CachedData object is
+    // destroyed. If the policy is BufferOwned, the given data will be deleted
+    // (with delete[]) when the CachedData object is destroyed.
+    CachedData(const uint8_t* data, int length,
+               BufferPolicy buffer_policy = BufferNotOwned);
+    ~CachedData();
+    // TODO(marja): Async compilation; add constructors which take a callback
+    // which will be called when V8 no longer needs the data.
+    const uint8_t* data;
+    int length;
+    bool rejected;
+    BufferPolicy buffer_policy;
+
+    // Prevent copying.
+    CachedData(const CachedData&) = delete;
+    CachedData& operator=(const CachedData&) = delete;
+  };
+
+  /**
+   * Source code which can be then compiled to a UnboundScript or Script.
+   */
+  class Source {
+   public:
+    // Source takes ownership of CachedData.
+    V8_INLINE Source(Local<String> source_string, const ScriptOrigin& origin,
+           CachedData* cached_data = NULL);
+    V8_INLINE Source(Local<String> source_string,
+                     CachedData* cached_data = NULL);
+    V8_INLINE ~Source();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the Source object is
+    // alive.
+    V8_INLINE const CachedData* GetCachedData() const;
+
+    V8_INLINE const ScriptOriginOptions& GetResourceOptions() const;
+
+    // Prevent copying.
+    Source(const Source&) = delete;
+    Source& operator=(const Source&) = delete;
+
+   private:
+    friend class ScriptCompiler;
+
+    Local<String> source_string;
+
+    // Origin information
+    Local<Value> resource_name;
+    Local<Integer> resource_line_offset;
+    Local<Integer> resource_column_offset;
+    ScriptOriginOptions resource_options;
+    Local<Value> source_map_url;
+
+    // Cached data from previous compilation (if a kConsume*Cache flag is
+    // set), or hold newly generated cache data (kProduce*Cache flags) are
+    // set when calling a compile method.
+    CachedData* cached_data;
+  };
+
+  /**
+   * For streaming incomplete script data to V8. The embedder should implement a
+   * subclass of this class.
+   */
+  class V8_EXPORT ExternalSourceStream {
+   public:
+    virtual ~ExternalSourceStream() {}
+
+    /**
+     * V8 calls this to request the next chunk of data from the embedder. This
+     * function will be called on a background thread, so it's OK to block and
+     * wait for the data, if the embedder doesn't have data yet. Returns the
+     * length of the data returned. When the data ends, GetMoreData should
+     * return 0. Caller takes ownership of the data.
+     *
+     * When streaming UTF-8 data, V8 handles multi-byte characters split between
+     * two data chunks, but doesn't handle multi-byte characters split between
+     * more than two data chunks. The embedder can avoid this problem by always
+     * returning at least 2 bytes of data.
+     *
+     * If the embedder wants to cancel the streaming, they should make the next
+     * GetMoreData call return 0. V8 will interpret it as end of data (and most
+     * probably, parsing will fail). The streaming task will return as soon as
+     * V8 has parsed the data it received so far.
+     */
+    virtual size_t GetMoreData(const uint8_t** src) = 0;
+
+    /**
+     * V8 calls this method to set a 'bookmark' at the current position in
+     * the source stream, for the purpose of (maybe) later calling
+     * ResetToBookmark. If ResetToBookmark is called later, then subsequent
+     * calls to GetMoreData should return the same data as they did when
+     * SetBookmark was called earlier.
+     *
+     * The embedder may return 'false' to indicate it cannot provide this
+     * functionality.
+     */
+    virtual bool SetBookmark();
+
+    /**
+     * V8 calls this to return to a previously set bookmark.
+     */
+    virtual void ResetToBookmark();
+  };
+
+
+  /**
+   * Source code which can be streamed into V8 in pieces. It will be parsed
+   * while streaming. It can be compiled after the streaming is complete.
+   * StreamedSource must be kept alive while the streaming task is ran (see
+   * ScriptStreamingTask below).
+   */
+  class V8_EXPORT StreamedSource {
+   public:
+    enum Encoding { ONE_BYTE, TWO_BYTE, UTF8 };
+
+    StreamedSource(ExternalSourceStream* source_stream, Encoding encoding);
+    ~StreamedSource();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the StreamedSource
+    // object is alive.
+    const CachedData* GetCachedData() const;
+
+    internal::StreamedSource* impl() const { return impl_; }
+
+    // Prevent copying.
+    StreamedSource(const StreamedSource&) = delete;
+    StreamedSource& operator=(const StreamedSource&) = delete;
+
+   private:
+    internal::StreamedSource* impl_;
+  };
+
+  /**
+   * A streaming task which the embedder must run on a background thread to
+   * stream scripts into V8. Returned by ScriptCompiler::StartStreamingScript.
+   */
+  class ScriptStreamingTask {
+   public:
+    virtual ~ScriptStreamingTask() {}
+    virtual void Run() = 0;
+  };
+
+  enum CompileOptions {
+    kNoCompileOptions = 0,
+    kProduceParserCache,
+    kConsumeParserCache,
+    kProduceCodeCache,
+    kConsumeCodeCache
+  };
+
+  /**
+   * Compiles the specified script (context-independent).
+   * Cached data as part of the source object can be optionally produced to be
+   * consumed later to speed up compilation of identical source scripts.
+   *
+   * Note that when producing cached data, the source must point to NULL for
+   * cached data. When consuming cached data, the cached data must have been
+   * produced by the same version of V8.
+   *
+   * \param source Script source code.
+   * \return Compiled script object (context independent; for running it must be
+   *   bound to a context).
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<UnboundScript> CompileUnbound(
+                           Isolate* isolate, Source* source,
+                           CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundScript(
+      Isolate* isolate, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles the specified script (bound to current context).
+   *
+   * \param source Script source code.
+   * \param pre_data Pre-parsing data, as obtained by ScriptData::PreCompile()
+   *   using pre_data speeds compilation if it's done multiple times.
+   *   Owned by caller, no references are kept when this function returns.
+   * \return Compiled script object, bound to the context that was active
+   *   when this function was called. When run it will always use this
+   *   context.
+   */
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<Script> Compile(Isolate* isolate, Source* source,
+                            CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Returns a task which streams script data into V8, or NULL if the script
+   * cannot be streamed. The user is responsible for running the task on a
+   * background thread and deleting it. When ran, the task starts parsing the
+   * script, and it will request data from the StreamedSource as needed. When
+   * ScriptStreamingTask::Run exits, all data has been streamed and the script
+   * can be compiled (see Compile below).
+   *
+   * This API allows to start the streaming with as little data as possible, and
+   * the remaining data (for example, the ScriptOrigin) is passed to Compile.
+   */
+  static ScriptStreamingTask* StartStreamingScript(
+      Isolate* isolate, StreamedSource* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles a streamed script (bound to current context).
+   *
+   * This can only be called after the streaming has finished
+   * (ScriptStreamingTask has been run). V8 doesn't construct the source string
+   * during streaming, so the embedder needs to pass the full source here.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<Script> Compile(Isolate* isolate,
+                                             StreamedSource* source,
+                                             Local<String> full_source_string,
+                                             const ScriptOrigin& origin));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, StreamedSource* source,
+      Local<String> full_source_string, const ScriptOrigin& origin);
+
+  /**
+   * Return a version tag for CachedData for the current V8 version & flags.
+   *
+   * This value is meant only for determining whether a previously generated
+   * CachedData instance is still valid; the tag has no other meaing.
+   *
+   * Background: The data carried by CachedData may depend on the exact
+   *   V8 version number or current compiler flags. This means that when
+   *   persisting CachedData, the embedder must take care to not pass in
+   *   data from another V8 version, or the same version with different
+   *   features enabled.
+   *
+   *   The easiest way to do so is to clear the embedder's cache on any
+   *   such change.
+   *
+   *   Alternatively, this tag can be stored alongside the cached data and
+   *   compared when it is being used.
+   */
+  static uint32_t CachedDataVersionTag();
+
+  /**
+   * This is an unfinished experimental feature, and is only exposed
+   * here for internal testing purposes. DO NOT USE.
+   *
+   * Compile an ES module, returning a Module that encapsulates
+   * the compiled code.
+   *
+   * Corresponds to the ParseModule abstract operation in the
+   * ECMAScript specification.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Module> CompileModule(
+      Isolate* isolate, Source* source);
+
+  /**
+   * Compile a function for a given context. This is equivalent to running
+   *
+   * with (obj) {
+   *   return function(args) { ... }
+   * }
+   *
+   * It is possible to specify multiple context extensions (obj in the above
+   * example).
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Function> CompileFunctionInContext(
+                               Isolate* isolate, Source* source,
+                               Local<Context> context, size_t arguments_count,
+                               Local<String> arguments[],
+                               size_t context_extension_count,
+                               Local<Object> context_extensions[]));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Function> CompileFunctionInContext(
+      Local<Context> context, Source* source, size_t arguments_count,
+      Local<String> arguments[], size_t context_extension_count,
+      Local<Object> context_extensions[]);
+
+ private:
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundInternal(
+      Isolate* isolate, Source* source, CompileOptions options);
+};
+
+
+/**
+ * An error message.
+ */
+class V8_EXPORT Message {
+ public:
+  Local<String> Get() const;
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<String> GetSourceLine() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> GetSourceLine(
+      Local<Context> context) const;
+
+  /**
+   * Returns the origin for the script from where the function causing the
+   * error originates.
+   */
+  ScriptOrigin GetScriptOrigin() const;
+
+  /**
+   * Returns the resource name for the script from where the function causing
+   * the error originates.
+   */
+  Local<Value> GetScriptResourceName() const;
+
+  /**
+   * Exception stack trace. By default stack traces are not captured for
+   * uncaught exceptions. SetCaptureStackTraceForUncaughtExceptions allows
+   * to change this option.
+   */
+  Local<StackTrace> GetStackTrace() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetLineNumber() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetLineNumber(Local<Context> context) const;
+
+  /**
+   * Returns the index within the script of the first character where
+   * the error occurred.
+   */
+  int GetStartPosition() const;
+
+  /**
+   * Returns the index within the script of the last character where
+   * the error occurred.
+   */
+  int GetEndPosition() const;
+
+  /**
+   * Returns the error level of the message.
+   */
+  int ErrorLevel() const;
+
+  /**
+   * Returns the index within the line of the first character where
+   * the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetStartColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetStartColumn(Local<Context> context) const;
+
+  /**
+   * Returns the index within the line of the last character where
+   * the error occurred.
+   */
+  V8_DEPRECATED("Use maybe version", int GetEndColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetEndColumn(Local<Context> context) const;
+
+  /**
+   * Passes on the value set by the embedder when it fed the script from which
+   * this Message was generated to V8.
+   */
+  bool IsSharedCrossOrigin() const;
+  bool IsOpaque() const;
+
+  // TODO(1245381): Print to a string instead of on a FILE.
+  static void PrintCurrentStackTrace(Isolate* isolate, FILE* out);
+
+  static const int kNoLineNumberInfo = 0;
+  static const int kNoColumnInfo = 0;
+  static const int kNoScriptIdInfo = 0;
+};
+
+
+/**
+ * Representation of a JavaScript stack trace. The information collected is a
+ * snapshot of the execution stack and the information remains valid after
+ * execution continues.
+ */
+class V8_EXPORT StackTrace {
+ public:
+  /**
+   * Flags that determine what information is placed captured for each
+   * StackFrame when grabbing the current stack trace.
+   * Note: these options are deprecated and we always collect all available
+   * information (kDetailed).
+   */
+  enum StackTraceOptions {
+    kLineNumber = 1,
+    kColumnOffset = 1 << 1 | kLineNumber,
+    kScriptName = 1 << 2,
+    kFunctionName = 1 << 3,
+    kIsEval = 1 << 4,
+    kIsConstructor = 1 << 5,
+    kScriptNameOrSourceURL = 1 << 6,
+    kScriptId = 1 << 7,
+    kExposeFramesAcrossSecurityOrigins = 1 << 8,
+    kOverview = kLineNumber | kColumnOffset | kScriptName | kFunctionName,
+    kDetailed = kOverview | kIsEval | kIsConstructor | kScriptNameOrSourceURL
+  };
+
+  /**
+   * Returns a StackFrame at a particular index.
+   */
+  Local<StackFrame> GetFrame(uint32_t index) const;
+
+  /**
+   * Returns the number of StackFrames.
+   */
+  int GetFrameCount() const;
+
+  /**
+   * Returns StackTrace as a v8::Array that contains StackFrame objects.
+   */
+  V8_DEPRECATED("Use native API instead", Local<Array> AsArray());
+
+  /**
+   * Grab a snapshot of the current JavaScript execution stack.
+   *
+   * \param frame_limit The maximum number of stack frames we want to capture.
+   * \param options Enumerates the set of things we will capture for each
+   *   StackFrame.
+   */
+  static Local<StackTrace> CurrentStackTrace(
+      Isolate* isolate, int frame_limit, StackTraceOptions options = kDetailed);
+};
+
+
+/**
+ * A single JavaScript stack frame.
+ */
+class V8_EXPORT StackFrame {
+ public:
+  /**
+   * Returns the number, 1-based, of the line for the associate function call.
+   * This method will return Message::kNoLineNumberInfo if it is unable to
+   * retrieve the line number, or if kLineNumber was not passed as an option
+   * when capturing the StackTrace.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns the 1-based column offset on the line for the associated function
+   * call.
+   * This method will return Message::kNoColumnInfo if it is unable to retrieve
+   * the column number, or if kColumnOffset was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetColumn() const;
+
+  /**
+   * Returns the id of the script for the function for this StackFrame.
+   * This method will return Message::kNoScriptIdInfo if it is unable to
+   * retrieve the script id, or if kScriptId was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetScriptId() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame.
+   */
+  Local<String> GetScriptName() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame or sourceURL value if the script name
+   * is undefined and its source ends with //# sourceURL=... string or
+   * deprecated //@ sourceURL=... string.
+   */
+  Local<String> GetScriptNameOrSourceURL() const;
+
+  /**
+   * Returns the name of the function associated with this stack frame.
+   */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns whether or not the associated function is compiled via a call to
+   * eval().
+   */
+  bool IsEval() const;
+
+  /**
+   * Returns whether or not the associated function is called as a
+   * constructor via "new".
+   */
+  bool IsConstructor() const;
+
+  /**
+   * Returns whether or not the associated functions is defined in wasm.
+   */
+  bool IsWasm() const;
+};
+
+
+// A StateTag represents a possible state of the VM.
+enum StateTag { JS, GC, COMPILER, OTHER, EXTERNAL, IDLE };
+
+// A RegisterState represents the current state of registers used
+// by the sampling profiler API.
+struct RegisterState {
+  RegisterState() : pc(nullptr), sp(nullptr), fp(nullptr) {}
+  void* pc;  // Instruction pointer.
+  void* sp;  // Stack pointer.
+  void* fp;  // Frame pointer.
+};
+
+// The output structure filled up by GetStackSample API function.
+struct SampleInfo {
+  size_t frames_count;            // Number of frames collected.
+  StateTag vm_state;              // Current VM state.
+  void* external_callback_entry;  // External callback address if VM is
+                                  // executing an external callback.
+};
+
+/**
+ * A JSON Parser and Stringifier.
+ */
+class V8_EXPORT JSON {
+ public:
+  /**
+   * Tries to parse the string |json_string| and returns it as value if
+   * successful.
+   *
+   * \param json_string The string to parse.
+   * \return The corresponding value if successfully parsed.
+   */
+  static V8_DEPRECATED("Use the maybe version taking context",
+                       Local<Value> Parse(Local<String> json_string));
+  static V8_DEPRECATE_SOON("Use the maybe version taking context",
+                           MaybeLocal<Value> Parse(Isolate* isolate,
+                                                   Local<String> json_string));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> Parse(
+      Local<Context> context, Local<String> json_string);
+
+  /**
+   * Tries to stringify the JSON-serializable object |json_object| and returns
+   * it as string if successful.
+   *
+   * \param json_object The JSON-serializable object to stringify.
+   * \return The corresponding string if successfully stringified.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> Stringify(
+      Local<Context> context, Local<Object> json_object,
+      Local<String> gap = Local<String>());
+};
+
+/**
+ * Value serialization compatible with the HTML structured clone algorithm.
+ * The format is backward-compatible (i.e. safe to store to disk).
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueSerializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * Handles the case where a DataCloneError would be thrown in the structured
+     * clone spec. Other V8 embedders may throw some other appropriate exception
+     * type.
+     */
+    virtual void ThrowDataCloneError(Local<String> message) = 0;
+
+    /**
+     * The embedder overrides this method to write some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * Nothing<bool>() returned.
+     */
+    virtual Maybe<bool> WriteHostObject(Isolate* isolate, Local<Object> object);
+
+    /**
+     * Called when the ValueSerializer is going to serialize a
+     * SharedArrayBuffer object. The embedder must return an ID for the
+     * object, using the same ID if this SharedArrayBuffer has already been
+     * serialized in this buffer. When deserializing, this ID will be passed to
+     * ValueDeserializer::TransferSharedArrayBuffer as |transfer_id|.
+     *
+     * If the object cannot be serialized, an
+     * exception should be thrown and Nothing<uint32_t>() returned.
+     */
+    virtual Maybe<uint32_t> GetSharedArrayBufferId(
+        Isolate* isolate, Local<SharedArrayBuffer> shared_array_buffer);
+
+    virtual Maybe<uint32_t> GetWasmModuleTransferId(
+        Isolate* isolate, Local<WasmCompiledModule> module);
+    /**
+     * Allocates memory for the buffer of at least the size provided. The actual
+     * size (which may be greater or equal) is written to |actual_size|. If no
+     * buffer has been allocated yet, nullptr will be provided.
+     *
+     * If the memory cannot be allocated, nullptr should be returned.
+     * |actual_size| will be ignored. It is assumed that |old_buffer| is still
+     * valid in this case and has not been modified.
+     */
+    virtual void* ReallocateBufferMemory(void* old_buffer, size_t size,
+                                         size_t* actual_size);
+
+    /**
+     * Frees a buffer allocated with |ReallocateBufferMemory|.
+     */
+    virtual void FreeBufferMemory(void* buffer);
+  };
+
+  explicit ValueSerializer(Isolate* isolate);
+  ValueSerializer(Isolate* isolate, Delegate* delegate);
+  ~ValueSerializer();
+
+  /**
+   * Writes out a header, which includes the format version.
+   */
+  void WriteHeader();
+
+  /**
+   * Serializes a JavaScript value into the buffer.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> WriteValue(Local<Context> context,
+                                               Local<Value> value);
+
+  /**
+   * Returns the stored data. This serializer should not be used once the buffer
+   * is released. The contents are undefined if a previous write has failed.
+   */
+  V8_DEPRECATE_SOON("Use Release()", std::vector<uint8_t> ReleaseBuffer());
+
+  /**
+   * Returns the stored data (allocated using the delegate's
+   * AllocateBufferMemory) and its size. This serializer should not be used once
+   * the buffer is released. The contents are undefined if a previous write has
+   * failed.
+   */
+  V8_WARN_UNUSED_RESULT std::pair<uint8_t*, size_t> Release();
+
+  /**
+   * Marks an ArrayBuffer as havings its contents transferred out of band.
+   * Pass the corresponding ArrayBuffer in the deserializing context to
+   * ValueDeserializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   */
+  V8_DEPRECATE_SOON("Use Delegate::GetSharedArrayBufferId",
+                    void TransferSharedArrayBuffer(
+                        uint32_t transfer_id,
+                        Local<SharedArrayBuffer> shared_array_buffer));
+
+  /**
+   * Indicate whether to treat ArrayBufferView objects as host objects,
+   * i.e. pass them to Delegate::WriteHostObject. This should not be
+   * called when no Delegate was passed.
+   *
+   * The default is not to treat ArrayBufferViews as host objects.
+   */
+  void SetTreatArrayBufferViewsAsHostObjects(bool mode);
+
+  /**
+   * Write raw data in various common formats to the buffer.
+   * Note that integer types are written in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::WriteHostObject.
+   */
+  void WriteUint32(uint32_t value);
+  void WriteUint64(uint64_t value);
+  void WriteDouble(double value);
+  void WriteRawBytes(const void* source, size_t length);
+
+ private:
+  ValueSerializer(const ValueSerializer&) = delete;
+  void operator=(const ValueSerializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * Deserializes values from data written with ValueSerializer, or a compatible
+ * implementation.
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueDeserializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * The embedder overrides this method to read some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * MaybeLocal<Object>() returned.
+     */
+    virtual MaybeLocal<Object> ReadHostObject(Isolate* isolate);
+
+    /**
+     * Get a WasmCompiledModule given a transfer_id previously provided
+     * by ValueSerializer::GetWasmModuleTransferId
+     */
+    virtual MaybeLocal<WasmCompiledModule> GetWasmModuleFromId(
+        Isolate* isolate, uint32_t transfer_id);
+  };
+
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size);
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size,
+                    Delegate* delegate);
+  ~ValueDeserializer();
+
+  /**
+   * Reads and validates a header (including the format version).
+   * May, for example, reject an invalid or unsupported wire format.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> ReadHeader(Local<Context> context);
+
+  /**
+   * Deserializes a JavaScript value from the buffer.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> ReadValue(Local<Context> context);
+
+  /**
+   * Accepts the array buffer corresponding to the one passed previously to
+   * ValueSerializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   * The id is not necessarily in the same namespace as unshared ArrayBuffer
+   * objects.
+   */
+  void TransferSharedArrayBuffer(uint32_t id,
+                                 Local<SharedArrayBuffer> shared_array_buffer);
+
+  /**
+   * Must be called before ReadHeader to enable support for reading the legacy
+   * wire format (i.e., which predates this being shipped).
+   *
+   * Don't use this unless you need to read data written by previous versions of
+   * blink::ScriptValueSerializer.
+   */
+  void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);
+
+  /**
+   * Expect inline wasm in the data stream (rather than in-memory transfer)
+   */
+  void SetExpectInlineWasm(bool allow_inline_wasm);
+
+  /**
+   * Reads the underlying wire format version. Likely mostly to be useful to
+   * legacy code reading old wire format versions. Must be called after
+   * ReadHeader.
+   */
+  uint32_t GetWireFormatVersion() const;
+
+  /**
+   * Reads raw data in various common formats to the buffer.
+   * Note that integer types are read in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::ReadHostObject.
+   */
+  V8_WARN_UNUSED_RESULT bool ReadUint32(uint32_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadUint64(uint64_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadDouble(double* value);
+  V8_WARN_UNUSED_RESULT bool ReadRawBytes(size_t length, const void** data);
+
+ private:
+  ValueDeserializer(const ValueDeserializer&) = delete;
+  void operator=(const ValueDeserializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * A map whose keys are referenced weakly. It is similar to JavaScript WeakMap
+ * but can be created without entering a v8::Context and hence shouldn't
+ * escape to JavaScript.
+ */
+class V8_EXPORT NativeWeakMap : public Data {
+ public:
+  static Local<NativeWeakMap> New(Isolate* isolate);
+  void Set(Local<Value> key, Local<Value> value);
+  Local<Value> Get(Local<Value> key) const;
+  bool Has(Local<Value> key);
+  bool Delete(Local<Value> key);
+};
+
+
+// --- Value ---
+
+
+/**
+ * The superclass of all JavaScript values and objects.
+ */
+class V8_EXPORT Value : public Data {
+ public:
+  /**
+   * Returns true if this value is the undefined value.  See ECMA-262
+   * 4.3.10.
+   */
+  V8_INLINE bool IsUndefined() const;
+
+  /**
+   * Returns true if this value is the null value.  See ECMA-262
+   * 4.3.11.
+   */
+  V8_INLINE bool IsNull() const;
+
+  /**
+   * Returns true if this value is either the null or the undefined value.
+   * See ECMA-262
+   * 4.3.11. and 4.3.12
+   */
+  V8_INLINE bool IsNullOrUndefined() const;
+
+  /**
+  * Returns true if this value is true.
+  */
+  bool IsTrue() const;
+
+  /**
+   * Returns true if this value is false.
+   */
+  bool IsFalse() const;
+
+  /**
+   * Returns true if this value is a symbol or a string.
+   */
+  bool IsName() const;
+
+  /**
+   * Returns true if this value is an instance of the String type.
+   * See ECMA-262 8.4.
+   */
+  V8_INLINE bool IsString() const;
+
+  /**
+   * Returns true if this value is a symbol.
+   */
+  bool IsSymbol() const;
+
+  /**
+   * Returns true if this value is a function.
+   */
+  bool IsFunction() const;
+
+  /**
+   * Returns true if this value is an array. Note that it will return false for
+   * an Proxy for an array.
+   */
+  bool IsArray() const;
+
+  /**
+   * Returns true if this value is an object.
+   */
+  bool IsObject() const;
+
+  /**
+   * Returns true if this value is boolean.
+   */
+  bool IsBoolean() const;
+
+  /**
+   * Returns true if this value is a number.
+   */
+  bool IsNumber() const;
+
+  /**
+   * Returns true if this value is external.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this value is a 32-bit signed integer.
+   */
+  bool IsInt32() const;
+
+  /**
+   * Returns true if this value is a 32-bit unsigned integer.
+   */
+  bool IsUint32() const;
+
+  /**
+   * Returns true if this value is a Date.
+   */
+  bool IsDate() const;
+
+  /**
+   * Returns true if this value is an Arguments object.
+   */
+  bool IsArgumentsObject() const;
+
+  /**
+   * Returns true if this value is a Boolean object.
+   */
+  bool IsBooleanObject() const;
+
+  /**
+   * Returns true if this value is a Number object.
+   */
+  bool IsNumberObject() const;
+
+  /**
+   * Returns true if this value is a String object.
+   */
+  bool IsStringObject() const;
+
+  /**
+   * Returns true if this value is a Symbol object.
+   */
+  bool IsSymbolObject() const;
+
+  /**
+   * Returns true if this value is a NativeError.
+   */
+  bool IsNativeError() const;
+
+  /**
+   * Returns true if this value is a RegExp.
+   */
+  bool IsRegExp() const;
+
+  /**
+   * Returns true if this value is an async function.
+   */
+  bool IsAsyncFunction() const;
+
+  /**
+   * Returns true if this value is a Generator function.
+   */
+  bool IsGeneratorFunction() const;
+
+  /**
+   * Returns true if this value is a Generator object (iterator).
+   */
+  bool IsGeneratorObject() const;
+
+  /**
+   * Returns true if this value is a Promise.
+   */
+  bool IsPromise() const;
+
+  /**
+   * Returns true if this value is a Map.
+   */
+  bool IsMap() const;
+
+  /**
+   * Returns true if this value is a Set.
+   */
+  bool IsSet() const;
+
+  /**
+   * Returns true if this value is a Map Iterator.
+   */
+  bool IsMapIterator() const;
+
+  /**
+   * Returns true if this value is a Set Iterator.
+   */
+  bool IsSetIterator() const;
+
+  /**
+   * Returns true if this value is a WeakMap.
+   */
+  bool IsWeakMap() const;
+
+  /**
+   * Returns true if this value is a WeakSet.
+   */
+  bool IsWeakSet() const;
+
+  /**
+   * Returns true if this value is an ArrayBuffer.
+   */
+  bool IsArrayBuffer() const;
+
+  /**
+   * Returns true if this value is an ArrayBufferView.
+   */
+  bool IsArrayBufferView() const;
+
+  /**
+   * Returns true if this value is one of TypedArrays.
+   */
+  bool IsTypedArray() const;
+
+  /**
+   * Returns true if this value is an Uint8Array.
+   */
+  bool IsUint8Array() const;
+
+  /**
+   * Returns true if this value is an Uint8ClampedArray.
+   */
+  bool IsUint8ClampedArray() const;
+
+  /**
+   * Returns true if this value is an Int8Array.
+   */
+  bool IsInt8Array() const;
+
+  /**
+   * Returns true if this value is an Uint16Array.
+   */
+  bool IsUint16Array() const;
+
+  /**
+   * Returns true if this value is an Int16Array.
+   */
+  bool IsInt16Array() const;
+
+  /**
+   * Returns true if this value is an Uint32Array.
+   */
+  bool IsUint32Array() const;
+
+  /**
+   * Returns true if this value is an Int32Array.
+   */
+  bool IsInt32Array() const;
+
+  /**
+   * Returns true if this value is a Float32Array.
+   */
+  bool IsFloat32Array() const;
+
+  /**
+   * Returns true if this value is a Float64Array.
+   */
+  bool IsFloat64Array() const;
+
+  /**
+   * Returns true if this value is a DataView.
+   */
+  bool IsDataView() const;
+
+  /**
+   * Returns true if this value is a SharedArrayBuffer.
+   * This is an experimental feature.
+   */
+  bool IsSharedArrayBuffer() const;
+
+  /**
+   * Returns true if this value is a JavaScript Proxy.
+   */
+  bool IsProxy() const;
+
+  bool IsWebAssemblyCompiledModule() const;
+
+  V8_WARN_UNUSED_RESULT MaybeLocal<Boolean> ToBoolean(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToDetailString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> ToObject(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Integer> ToInteger(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToUint32(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Int32> ToInt32(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Boolean> ToBoolean(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Number> ToNumber(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<String> ToString(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<String> ToDetailString(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Object> ToObject(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Integer> ToInteger(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<Uint32> ToUint32(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Int32> ToInt32(Isolate* isolate) const);
+
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Boolean> ToBoolean() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Number> ToNumber() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<String> ToString() const);
+  inline V8_DEPRECATED("Use maybe version",
+                       Local<String> ToDetailString() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<Object> ToObject() const);
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Integer> ToInteger() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Uint32> ToUint32() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Int32> ToInt32() const);
+
+  /**
+   * Attempts to convert a string to an array index.
+   * Returns an empty handle if the conversion fails.
+   */
+  V8_DEPRECATED("Use maybe version", Local<Uint32> ToArrayIndex() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToArrayIndex(
+      Local<Context> context) const;
+
+  V8_WARN_UNUSED_RESULT Maybe<bool> BooleanValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<double> NumberValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int64_t> IntegerValue(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<uint32_t> Uint32Value(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int32_t> Int32Value(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version", bool BooleanValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", double NumberValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", int64_t IntegerValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", uint32_t Uint32Value() const);
+  V8_DEPRECATE_SOON("Use maybe version", int32_t Int32Value() const);
+
+  /** JS == */
+  V8_DEPRECATE_SOON("Use maybe version", bool Equals(Local<Value> that) const);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Equals(Local<Context> context,
+                                           Local<Value> that) const;
+  bool StrictEquals(Local<Value> that) const;
+  bool SameValue(Local<Value> that) const;
+
+  template <class T> V8_INLINE static Value* Cast(T* value);
+
+  Local<String> TypeOf(Isolate*);
+
+  Maybe<bool> InstanceOf(Local<Context> context, Local<Object> object);
+
+ private:
+  V8_INLINE bool QuickIsUndefined() const;
+  V8_INLINE bool QuickIsNull() const;
+  V8_INLINE bool QuickIsNullOrUndefined() const;
+  V8_INLINE bool QuickIsString() const;
+  bool FullIsUndefined() const;
+  bool FullIsNull() const;
+  bool FullIsString() const;
+};
+
+
+/**
+ * The superclass of primitive values.  See ECMA-262 4.3.2.
+ */
+class V8_EXPORT Primitive : public Value { };
+
+
+/**
+ * A primitive boolean value (ECMA-262, 4.3.14).  Either the true
+ * or false value.
+ */
+class V8_EXPORT Boolean : public Primitive {
+ public:
+  bool Value() const;
+  V8_INLINE static Boolean* Cast(v8::Value* obj);
+  V8_INLINE static Local<Boolean> New(Isolate* isolate, bool value);
+
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A superclass for symbols and strings.
+ */
+class V8_EXPORT Name : public Primitive {
+ public:
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses an inline property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  V8_INLINE static Name* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * A flag describing different modes of string creation.
+ *
+ * Aside from performance implications there are no differences between the two
+ * creation modes.
+ */
+enum class NewStringType {
+  /**
+   * Create a new string, always allocating new storage memory.
+   */
+  kNormal,
+
+  /**
+   * Acts as a hint that the string should be created in the
+   * old generation heap space and be deduplicated if an identical string
+   * already exists.
+   */
+  kInternalized
+};
+
+/**
+ * A JavaScript string value (ECMA-262, 4.3.17).
+ */
+class V8_EXPORT String : public Name {
+ public:
+  static const int kMaxLength = (1 << 28) - 16;
+
+  enum Encoding {
+    UNKNOWN_ENCODING = 0x1,
+    TWO_BYTE_ENCODING = 0x0,
+    ONE_BYTE_ENCODING = 0x8
+  };
+  /**
+   * Returns the number of characters (UTF-16 code units) in this string.
+   */
+  int Length() const;
+
+  /**
+   * Returns the number of bytes in the UTF-8 encoded
+   * representation of this string.
+   */
+  int Utf8Length() const;
+
+  /**
+   * Returns whether this string is known to contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Does not read the string.
+   * False negatives are possible.
+   */
+  bool IsOneByte() const;
+
+  /**
+   * Returns whether this string contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Will read the entire string in some cases.
+   */
+  bool ContainsOnlyOneByte() const;
+
+  /**
+   * Write the contents of the string to an external buffer.
+   * If no arguments are given, expects the buffer to be large
+   * enough to hold the entire string and NULL terminator. Copies
+   * the contents of the string and the NULL terminator into the
+   * buffer.
+   *
+   * WriteUtf8 will not write partial UTF-8 sequences, preferring to stop
+   * before the end of the buffer.
+   *
+   * Copies up to length characters into the output buffer.
+   * Only null-terminates if there is enough space in the buffer.
+   *
+   * \param buffer The buffer into which the string will be copied.
+   * \param start The starting position within the string at which
+   * copying begins.
+   * \param length The number of characters to copy from the string.  For
+   *    WriteUtf8 the number of bytes in the buffer.
+   * \param nchars_ref The number of characters written, can be NULL.
+   * \param options Various options that might affect performance of this or
+   *    subsequent operations.
+   * \return The number of characters copied to the buffer excluding the null
+   *    terminator.  For WriteUtf8: The number of bytes copied to the buffer
+   *    including the null terminator (if written).
+   */
+  enum WriteOptions {
+    NO_OPTIONS = 0,
+    HINT_MANY_WRITES_EXPECTED = 1,
+    NO_NULL_TERMINATION = 2,
+    PRESERVE_ONE_BYTE_NULL = 4,
+    // Used by WriteUtf8 to replace orphan surrogate code units with the
+    // unicode replacement character. Needs to be set to guarantee valid UTF-8
+    // output.
+    REPLACE_INVALID_UTF8 = 8
+  };
+
+  // 16-bit character codes.
+  int Write(uint16_t* buffer,
+            int start = 0,
+            int length = -1,
+            int options = NO_OPTIONS) const;
+  // One byte characters.
+  int WriteOneByte(uint8_t* buffer,
+                   int start = 0,
+                   int length = -1,
+                   int options = NO_OPTIONS) const;
+  // UTF-8 encoded characters.
+  int WriteUtf8(char* buffer,
+                int length = -1,
+                int* nchars_ref = NULL,
+                int options = NO_OPTIONS) const;
+
+  /**
+   * A zero length string.
+   */
+  V8_INLINE static Local<String> Empty(Isolate* isolate);
+
+  /**
+   * Returns true if the string is external
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if the string is both external and one-byte.
+   */
+  bool IsExternalOneByte() const;
+
+  class V8_EXPORT ExternalStringResourceBase {  // NOLINT
+   public:
+    virtual ~ExternalStringResourceBase() {}
+
+    virtual bool IsCompressible() const { return false; }
+
+   protected:
+    ExternalStringResourceBase() {}
+
+    /**
+     * Internally V8 will call this Dispose method when the external string
+     * resource is no longer needed. The default implementation will use the
+     * delete operator. This method can be overridden in subclasses to
+     * control how allocated external string resources are disposed.
+     */
+    virtual void Dispose() { delete this; }
+
+    // Disallow copying and assigning.
+    ExternalStringResourceBase(const ExternalStringResourceBase&) = delete;
+    void operator=(const ExternalStringResourceBase&) = delete;
+
+   private:
+    friend class internal::Heap;
+    friend class v8::String;
+  };
+
+  /**
+   * An ExternalStringResource is a wrapper around a two-byte string
+   * buffer that resides outside V8's heap. Implement an
+   * ExternalStringResource to manage the life cycle of the underlying
+   * buffer.  Note that the string data must be immutable.
+   */
+  class V8_EXPORT ExternalStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalStringResource() {}
+
+    /**
+     * The string data from the underlying buffer.
+     */
+    virtual const uint16_t* data() const = 0;
+
+    /**
+     * The length of the string. That is, the number of two-byte characters.
+     */
+    virtual size_t length() const = 0;
+
+   protected:
+    ExternalStringResource() {}
+  };
+
+  /**
+   * An ExternalOneByteStringResource is a wrapper around an one-byte
+   * string buffer that resides outside V8's heap. Implement an
+   * ExternalOneByteStringResource to manage the life cycle of the
+   * underlying buffer.  Note that the string data must be immutable
+   * and that the data must be Latin-1 and not UTF-8, which would require
+   * special treatment internally in the engine and do not allow efficient
+   * indexing.  Use String::New or convert to 16 bit data for non-Latin1.
+   */
+
+  class V8_EXPORT ExternalOneByteStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalOneByteStringResource() {}
+    /** The string data from the underlying buffer.*/
+    virtual const char* data() const = 0;
+    /** The number of Latin-1 characters in the string.*/
+    virtual size_t length() const = 0;
+   protected:
+    ExternalOneByteStringResource() {}
+  };
+
+  /**
+   * If the string is an external string, return the ExternalStringResourceBase
+   * regardless of the encoding, otherwise return NULL.  The encoding of the
+   * string is returned in encoding_out.
+   */
+  V8_INLINE ExternalStringResourceBase* GetExternalStringResourceBase(
+      Encoding* encoding_out) const;
+
+  /**
+   * Get the ExternalStringResource for an external string.  Returns
+   * NULL if IsExternal() doesn't return true.
+   */
+  V8_INLINE ExternalStringResource* GetExternalStringResource() const;
+
+  /**
+   * Get the ExternalOneByteStringResource for an external one-byte string.
+   * Returns NULL if IsExternalOneByte() doesn't return true.
+   */
+  const ExternalOneByteStringResource* GetExternalOneByteStringResource() const;
+
+  V8_INLINE static String* Cast(v8::Value* obj);
+
+  // TODO(dcarney): remove with deprecation of New functions.
+  enum NewStringType {
+    kNormalString = static_cast<int>(v8::NewStringType::kNormal),
+    kInternalizedString = static_cast<int>(v8::NewStringType::kInternalized)
+  };
+
+  /** Allocates a new string from UTF-8 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromUtf8(Isolate* isolate, const char* data,
+                                NewStringType type = kNormalString,
+                                int length = -1));
+
+  /** Allocates a new string from UTF-8 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromUtf8(
+      Isolate* isolate, const char* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from Latin-1 data.*/
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<String> NewFromOneByte(Isolate* isolate, const uint8_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from Latin-1 data.  Only returns an empty value
+   * when length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromOneByte(
+      Isolate* isolate, const uint8_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from UTF-16 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromTwoByte(Isolate* isolate, const uint16_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from UTF-16 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromTwoByte(
+      Isolate* isolate, const uint16_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /**
+   * Creates a new string by concatenating the left and the right strings
+   * passed in as parameters.
+   */
+  static Local<String> Concat(Local<String> left, Local<String> right);
+
+  /**
+   * Creates a new external string using the data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<String> NewExternal(
+                           Isolate* isolate, ExternalStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalTwoByte(
+      Isolate* isolate, ExternalStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalStringResource* resource);
+
+  /**
+   * Creates a new external string using the one-byte data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewExternal(Isolate* isolate,
+                                ExternalOneByteStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalOneByte(
+      Isolate* isolate, ExternalOneByteStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalOneByteStringResource* resource);
+
+  /**
+   * Returns true if this string can be made external.
+   */
+  bool CanMakeExternal();
+
+  /**
+   * Converts an object to a UTF-8-encoded character array.  Useful if
+   * you want to print the object.  If conversion to a string fails
+   * (e.g. due to an exception in the toString() method of the object)
+   * then the length() method returns 0 and the * operator returns
+   * NULL.
+   */
+  class V8_EXPORT Utf8Value {
+   public:
+    explicit Utf8Value(Local<v8::Value> obj);
+    ~Utf8Value();
+    char* operator*() { return str_; }
+    const char* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Utf8Value(const Utf8Value&) = delete;
+    void operator=(const Utf8Value&) = delete;
+
+   private:
+    char* str_;
+    int length_;
+  };
+
+  /**
+   * Converts an object to a two-byte (UTF-16-encoded) string.
+   * If conversion to a string fails (eg. due to an exception in the toString()
+   * method of the object) then the length() method returns 0 and the * operator
+   * returns NULL.
+   */
+  class V8_EXPORT Value {
+   public:
+    explicit Value(Local<v8::Value> obj);
+    ~Value();
+    uint16_t* operator*() { return str_; }
+    const uint16_t* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Value(const Value&) = delete;
+    void operator=(const Value&) = delete;
+
+   private:
+    uint16_t* str_;
+    int length_;
+  };
+
+ private:
+  void VerifyExternalStringResourceBase(ExternalStringResourceBase* v,
+                                        Encoding encoding) const;
+  void VerifyExternalStringResource(ExternalStringResource* val) const;
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript symbol (ECMA-262 edition 6)
+ */
+class V8_EXPORT Symbol : public Name {
+ public:
+  /**
+   * Returns the print name string of the symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a symbol. If name is not empty, it will be used as the description.
+   */
+  static Local<Symbol> New(Isolate* isolate,
+                           Local<String> name = Local<String>());
+
+  /**
+   * Access global symbol registry.
+   * Note that symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys.
+   */
+  static Local<Symbol> For(Isolate *isolate, Local<String> name);
+
+  /**
+   * Retrieve a global symbol. Similar to |For|, but using a separate
+   * registry that is not accessible by (and cannot clash with) JavaScript code.
+   */
+  static Local<Symbol> ForApi(Isolate *isolate, Local<String> name);
+
+  // Well-known symbols
+  static Local<Symbol> GetHasInstance(Isolate* isolate);
+  static Local<Symbol> GetIsConcatSpreadable(Isolate* isolate);
+  static Local<Symbol> GetIterator(Isolate* isolate);
+  static Local<Symbol> GetMatch(Isolate* isolate);
+  static Local<Symbol> GetReplace(Isolate* isolate);
+  static Local<Symbol> GetSearch(Isolate* isolate);
+  static Local<Symbol> GetSplit(Isolate* isolate);
+  static Local<Symbol> GetToPrimitive(Isolate* isolate);
+  static Local<Symbol> GetToStringTag(Isolate* isolate);
+  static Local<Symbol> GetUnscopables(Isolate* isolate);
+
+  V8_INLINE static Symbol* Cast(Value* obj);
+
+ private:
+  Symbol();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A private symbol
+ *
+ * This is an experimental feature. Use at your own risk.
+ */
+class V8_EXPORT Private : public Data {
+ public:
+  /**
+   * Returns the print name string of the private symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a private symbol. If name is not empty, it will be the description.
+   */
+  static Local<Private> New(Isolate* isolate,
+                            Local<String> name = Local<String>());
+
+  /**
+   * Retrieve a global private symbol. If a symbol with this name has not
+   * been retrieved in the same isolate before, it is created.
+   * Note that private symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys,
+   * e.g., "Class#property".
+   */
+  static Local<Private> ForApi(Isolate* isolate, Local<String> name);
+
+ private:
+  Private();
+};
+
+
+/**
+ * A JavaScript number value (ECMA-262, 4.3.20)
+ */
+class V8_EXPORT Number : public Primitive {
+ public:
+  double Value() const;
+  static Local<Number> New(Isolate* isolate, double value);
+  V8_INLINE static Number* Cast(v8::Value* obj);
+ private:
+  Number();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a signed integer.
+ */
+class V8_EXPORT Integer : public Number {
+ public:
+  static Local<Integer> New(Isolate* isolate, int32_t value);
+  static Local<Integer> NewFromUnsigned(Isolate* isolate, uint32_t value);
+  int64_t Value() const;
+  V8_INLINE static Integer* Cast(v8::Value* obj);
+ private:
+  Integer();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit signed integer.
+ */
+class V8_EXPORT Int32 : public Integer {
+ public:
+  int32_t Value() const;
+  V8_INLINE static Int32* Cast(v8::Value* obj);
+
+ private:
+  Int32();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit unsigned integer.
+ */
+class V8_EXPORT Uint32 : public Integer {
+ public:
+  uint32_t Value() const;
+  V8_INLINE static Uint32* Cast(v8::Value* obj);
+
+ private:
+  Uint32();
+  static void CheckCast(v8::Value* obj);
+};
+
+/**
+ * PropertyAttribute.
+ */
+enum PropertyAttribute {
+  /** None. **/
+  None = 0,
+  /** ReadOnly, i.e., not writable. **/
+  ReadOnly = 1 << 0,
+  /** DontEnum, i.e., not enumerable. **/
+  DontEnum = 1 << 1,
+  /** DontDelete, i.e., not configurable. **/
+  DontDelete = 1 << 2
+};
+
+/**
+ * Accessor[Getter|Setter] are used as callback functions when
+ * setting|getting a particular property. See Object and ObjectTemplate's
+ * method SetAccessor.
+ */
+typedef void (*AccessorGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+typedef void (*AccessorNameGetterCallback)(
+    Local<Name> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+typedef void (*AccessorSetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+typedef void (*AccessorNameSetterCallback)(
+    Local<Name> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+
+
+/**
+ * Access control specifications.
+ *
+ * Some accessors should be accessible across contexts.  These
+ * accessors have an explicit access control parameter which specifies
+ * the kind of cross-context access that should be allowed.
+ *
+ * TODO(dcarney): Remove PROHIBITS_OVERWRITING as it is now unused.
+ */
+enum AccessControl {
+  DEFAULT               = 0,
+  ALL_CAN_READ          = 1,
+  ALL_CAN_WRITE         = 1 << 1,
+  PROHIBITS_OVERWRITING = 1 << 2
+};
+
+/**
+ * Property filter bits. They can be or'ed to build a composite filter.
+ */
+enum PropertyFilter {
+  ALL_PROPERTIES = 0,
+  ONLY_WRITABLE = 1,
+  ONLY_ENUMERABLE = 2,
+  ONLY_CONFIGURABLE = 4,
+  SKIP_STRINGS = 8,
+  SKIP_SYMBOLS = 16
+};
+
+/**
+ * Keys/Properties filter enums:
+ *
+ * KeyCollectionMode limits the range of collected properties. kOwnOnly limits
+ * the collected properties to the given Object only. kIncludesPrototypes will
+ * include all keys of the objects's prototype chain as well.
+ */
+enum class KeyCollectionMode { kOwnOnly, kIncludePrototypes };
+
+/**
+ * kIncludesIndices allows for integer indices to be collected, while
+ * kSkipIndices will exclude integer indicies from being collected.
+ */
+enum class IndexFilter { kIncludeIndices, kSkipIndices };
+
+/**
+ * Integrity level for objects.
+ */
+enum class IntegrityLevel { kFrozen, kSealed };
+
+/**
+ * A JavaScript object (ECMA-262, 4.3.3)
+ */
+class V8_EXPORT Object : public Value {
+ public:
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(Local<Value> key, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context,
+                                        Local<Value> key, Local<Value> value);
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(uint32_t index, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index,
+                                        Local<Value> value);
+
+  // Implements CreateDataProperty (ECMA-262, 7.3.4).
+  //
+  // Defines a configurable, writable, enumerable property with the given value
+  // on the object unless the property already exists and is not configurable
+  // or the object is not extensible.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       Local<Name> key,
+                                                       Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       uint32_t index,
+                                                       Local<Value> value);
+
+  // Implements DefineOwnProperty.
+  //
+  // In general, CreateDataProperty will be faster, however, does not allow
+  // for specifying attributes.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineOwnProperty(
+      Local<Context> context, Local<Name> key, Local<Value> value,
+      PropertyAttribute attributes = None);
+
+  // Implements Object.DefineProperty(O, P, Attributes), see Ecma-262 19.1.2.4.
+  //
+  // The defineProperty function is used to add an own property or
+  // update the attributes of an existing own property of an object.
+  //
+  // Both data and accessor descriptors can be used.
+  //
+  // In general, CreateDataProperty is faster, however, does not allow
+  // for specifying attributes or an accessor descriptor.
+  //
+  // The PropertyDescriptor can change when redefining a property.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineProperty(
+      Local<Context> context, Local<Name> key, PropertyDescriptor& descriptor);
+
+  // Sets an own property on this object bypassing interceptors and
+  // overriding accessors or read-only properties.
+  //
+  // Note that if the object has an interceptor the property will be set
+  // locally, but since the interceptor takes precedence the local property
+  // will only be returned if the interceptor doesn't return a value.
+  //
+  // Note also that this only works for named properties.
+  V8_DEPRECATED("Use CreateDataProperty / DefineOwnProperty",
+                bool ForceSet(Local<Value> key, Local<Value> value,
+                              PropertyAttribute attribs = None));
+  V8_DEPRECATE_SOON("Use CreateDataProperty / DefineOwnProperty",
+                    Maybe<bool> ForceSet(Local<Context> context,
+                                         Local<Value> key, Local<Value> value,
+                                         PropertyAttribute attribs = None));
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(Local<Value> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(uint32_t index));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              uint32_t index);
+
+  /**
+   * Gets the property attributes of a property which can be None or
+   * any combination of ReadOnly, DontEnum and DontDelete. Returns
+   * None when the property doesn't exist.
+   */
+  V8_DEPRECATED("Use maybe version",
+                PropertyAttribute GetPropertyAttributes(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetPropertyAttributes(
+      Local<Context> context, Local<Value> key);
+
+  /**
+   * Returns Object.getOwnPropertyDescriptor as per ES2016 section 19.1.2.6.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetOwnPropertyDescriptor(Local<Name> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetOwnPropertyDescriptor(
+      Local<Context> context, Local<Name> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Has(Local<Value> key));
+  /**
+   * Object::Has() calls the abstract operation HasProperty(O, P) described
+   * in ECMA-262, 7.3.10. Has() returns
+   * true, if the object has the property, either own or on the prototype chain.
+   * Interceptors, i.e., PropertyQueryCallbacks, are called if present.
+   *
+   * Has() has the same side effects as JavaScript's `variable in object`.
+   * For example, calling Has() on a revoked proxy will throw an exception.
+   *
+   * \note Has() converts the key to a name, which possibly calls back into
+   * JavaScript.
+   *
+   * See also v8::Object::HasOwnProperty() and
+   * v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Delete(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  V8_DEPRECATED("Use maybe version", bool Has(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        uint32_t index);
+
+  V8_DEPRECATED("Use maybe version", bool Delete(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           uint32_t index);
+
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<String> name,
+                                 AccessorGetterCallback getter,
+                                 AccessorSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<Name> name,
+                                 AccessorNameGetterCallback getter,
+                                 AccessorNameSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetAccessor(Local<Context> context,
+                          Local<Name> name,
+                          AccessorNameGetterCallback getter,
+                          AccessorNameSetterCallback setter = 0,
+                          MaybeLocal<Value> data = MaybeLocal<Value>(),
+                          AccessControl settings = DEFAULT,
+                          PropertyAttribute attribute = None);
+
+  void SetAccessorProperty(Local<Name> name, Local<Function> getter,
+                           Local<Function> setter = Local<Function>(),
+                           PropertyAttribute attribute = None,
+                           AccessControl settings = DEFAULT);
+
+  /**
+   * Sets a native data property like Template::SetNativeDataProperty, but
+   * this method sets on this object directly.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetNativeDataProperty(
+      Local<Context> context, Local<Name> name,
+      AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = nullptr,
+      Local<Value> data = Local<Value>(), PropertyAttribute attributes = None);
+
+  /**
+   * Functionality for private properties.
+   * This is an experimental feature, use at your own risk.
+   * Note: Private properties are not inherited. Do not rely on this, since it
+   * may change.
+   */
+  Maybe<bool> HasPrivate(Local<Context> context, Local<Private> key);
+  Maybe<bool> SetPrivate(Local<Context> context, Local<Private> key,
+                         Local<Value> value);
+  Maybe<bool> DeletePrivate(Local<Context> context, Local<Private> key);
+  MaybeLocal<Value> GetPrivate(Local<Context> context, Local<Private> key);
+
+  /**
+   * Returns an array containing the names of the enumerable properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context, KeyCollectionMode mode,
+      PropertyFilter property_filter, IndexFilter index_filter);
+
+  /**
+   * This function has the same functionality as GetPropertyNames but
+   * the returned array doesn't contain the names of properties from
+   * prototype objects.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetOwnPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context);
+
+  /**
+   * Returns an array containing the names of the filtered properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context, PropertyFilter filter);
+
+  /**
+   * Get the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  Local<Value> GetPrototype();
+
+  /**
+   * Set the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  V8_DEPRECATED("Use maybe version", bool SetPrototype(Local<Value> prototype));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetPrototype(Local<Context> context,
+                                                 Local<Value> prototype);
+
+  /**
+   * Finds an instance of the given function template in the prototype
+   * chain.
+   */
+  Local<Object> FindInstanceInPrototypeChain(Local<FunctionTemplate> tmpl);
+
+  /**
+   * Call builtin Object.prototype.toString on this object.
+   * This is different from Value::ToString() that may call
+   * user-defined toString function. This one does not.
+   */
+  V8_DEPRECATED("Use maybe version", Local<String> ObjectProtoToString());
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ObjectProtoToString(
+      Local<Context> context);
+
+  /**
+   * Returns the name of the function invoked as a constructor for this object.
+   */
+  Local<String> GetConstructorName();
+
+  /**
+   * Sets the integrity level of the object.
+   */
+  Maybe<bool> SetIntegrityLevel(Local<Context> context, IntegrityLevel level);
+
+  /** Gets the number of internal fields for this Object. */
+  int InternalFieldCount();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static int InternalFieldCount(
+      const PersistentBase<Object>& object) {
+    return object.val_->InternalFieldCount();
+  }
+
+  /** Gets the value from an internal field. */
+  V8_INLINE Local<Value> GetInternalField(int index);
+
+  /** Sets the value in an internal field. */
+  void SetInternalField(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from an internal field. This field
+   * must have been set by SetAlignedPointerInInternalField, everything else
+   * leads to undefined behavior.
+   */
+  V8_INLINE void* GetAlignedPointerFromInternalField(int index);
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static void* GetAlignedPointerFromInternalField(
+      const PersistentBase<Object>& object, int index) {
+    return object.val_->GetAlignedPointerFromInternalField(index);
+  }
+
+  /**
+   * Sets a 2-byte-aligned native pointer in an internal field. To retrieve such
+   * a field, GetAlignedPointerFromInternalField must be used, everything else
+   * leads to undefined behavior.
+   */
+  void SetAlignedPointerInInternalField(int index, void* value);
+  void SetAlignedPointerInInternalFields(int argc, int indices[],
+                                         void* values[]);
+
+  // Testers for local properties.
+  V8_DEPRECATED("Use maybe version", bool HasOwnProperty(Local<String> key));
+
+  /**
+   * HasOwnProperty() is like JavaScript's Object.prototype.hasOwnProperty().
+   *
+   * See also v8::Object::Has() and v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   Local<Name> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedProperty(Local<String> key));
+  /**
+   * Use HasRealNamedProperty() if you want to check if an object has an own
+   * property without causing side effects, i.e., without calling interceptors.
+   *
+   * This function is similar to v8::Object::HasOwnProperty(), but it does not
+   * call interceptors.
+   *
+   * \note Consider using non-masking interceptors, i.e., the interceptors are
+   * not called if the receiver has the real named property. See
+   * `v8::PropertyHandlerFlags::kNonMasking`.
+   *
+   * See also v8::Object::Has().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedProperty(Local<Context> context,
+                                                         Local<Name> key);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealIndexedProperty(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealIndexedProperty(
+      Local<Context> context, uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedCallbackProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedCallbackProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Local<Value> GetRealNamedPropertyInPrototypeChain(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedPropertyInPrototypeChain(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property in the prototype chain,
+   * which can be None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Maybe<PropertyAttribute> GetRealNamedPropertyAttributesInPrototypeChain(
+          Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute>
+  GetRealNamedPropertyAttributesInPrototypeChain(Local<Context> context,
+                                                 Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located on the object or
+   * in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetRealNamedProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property which can be
+   * None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+                    Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+      Local<Context> context, Local<Name> key);
+
+  /** Tests for a named lookup interceptor.*/
+  bool HasNamedLookupInterceptor();
+
+  /** Tests for an index lookup interceptor.*/
+  bool HasIndexedLookupInterceptor();
+
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses a hidden property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  /**
+   * Clone this object with a fast but shallow copy.  Values will point
+   * to the same values as the original object.
+   */
+  // TODO(dcarney): take an isolate and optionally bail out?
+  Local<Object> Clone();
+
+  /**
+   * Returns the context in which the object was created.
+   */
+  Local<Context> CreationContext();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static Local<Context> CreationContext(
+      const PersistentBase<Object>& object) {
+    return object.val_->CreationContext();
+  }
+
+  /**
+   * Checks whether a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * When an Object is callable this method returns true.
+   */
+  bool IsCallable();
+
+  /**
+   * True if this object is a constructor.
+   */
+  bool IsConstructor();
+
+  /**
+   * Call an Object as a function if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsFunction(Local<Value> recv, int argc,
+                                            Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsFunction(Local<Context> context,
+                                                         Local<Value> recv,
+                                                         int argc,
+                                                         Local<Value> argv[]);
+
+  /**
+   * Call an Object as a constructor if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * Note: This method behaves like the Function::NewInstance method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsConstructor(int argc, Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsConstructor(
+      Local<Context> context, int argc, Local<Value> argv[]);
+
+  /**
+   * Return the isolate to which the Object belongs to.
+   */
+  V8_DEPRECATE_SOON("Keep track of isolate correctly", Isolate* GetIsolate());
+
+  static Local<Object> New(Isolate* isolate);
+
+  V8_INLINE static Object* Cast(Value* obj);
+
+ private:
+  Object();
+  static void CheckCast(Value* obj);
+  Local<Value> SlowGetInternalField(int index);
+  void* SlowGetAlignedPointerFromInternalField(int index);
+};
+
+
+/**
+ * An instance of the built-in array constructor (ECMA-262, 15.4.2).
+ */
+class V8_EXPORT Array : public Object {
+ public:
+  uint32_t Length() const;
+
+  /**
+   * Clones an element at index |index|.  Returns an empty
+   * handle if cloning fails (for any reason).
+   */
+  V8_DEPRECATED("Cloning is not supported.",
+                Local<Object> CloneElementAt(uint32_t index));
+  V8_DEPRECATED("Cloning is not supported.",
+                MaybeLocal<Object> CloneElementAt(Local<Context> context,
+                                                  uint32_t index));
+
+  /**
+   * Creates a JavaScript array with the given length. If the length
+   * is negative the returned array will have length 0.
+   */
+  static Local<Array> New(Isolate* isolate, int length = 0);
+
+  V8_INLINE static Array* Cast(Value* obj);
+ private:
+  Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Map constructor (ECMA-262, 6th Edition, 23.1.1).
+ */
+class V8_EXPORT Map : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Map> Set(Local<Context> context,
+                                            Local<Value> key,
+                                            Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of length Size() * 2, where index N is the Nth key and
+   * index N + 1 is the Nth value.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Map.
+   */
+  static Local<Map> New(Isolate* isolate);
+
+  V8_INLINE static Map* Cast(Value* obj);
+
+ private:
+  Map();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Set constructor (ECMA-262, 6th Edition, 23.2.1).
+ */
+class V8_EXPORT Set : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Set> Add(Local<Context> context,
+                                            Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of the keys in this Set.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Set.
+   */
+  static Local<Set> New(Isolate* isolate);
+
+  V8_INLINE static Set* Cast(Value* obj);
+
+ private:
+  Set();
+  static void CheckCast(Value* obj);
+};
+
+
+template<typename T>
+class ReturnValue {
+ public:
+  template <class S> V8_INLINE ReturnValue(const ReturnValue<S>& that)
+      : value_(that.value_) {
+    TYPE_CHECK(T, S);
+  }
+  // Local setters
+  template <typename S>
+  V8_INLINE V8_DEPRECATE_SOON("Use Global<> instead",
+                              void Set(const Persistent<S>& handle));
+  template <typename S>
+  V8_INLINE void Set(const Global<S>& handle);
+  template <typename S>
+  V8_INLINE void Set(const Local<S> handle);
+  // Fast primitive setters
+  V8_INLINE void Set(bool value);
+  V8_INLINE void Set(double i);
+  V8_INLINE void Set(int32_t i);
+  V8_INLINE void Set(uint32_t i);
+  // Fast JS primitive setters
+  V8_INLINE void SetNull();
+  V8_INLINE void SetUndefined();
+  V8_INLINE void SetEmptyString();
+  // Convenience getter for Isolate
+  V8_INLINE Isolate* GetIsolate() const;
+
+  // Pointer setter: Uncompilable to prevent inadvertent misuse.
+  template <typename S>
+  V8_INLINE void Set(S* whatever);
+
+  // Getter. Creates a new Local<> so it comes with a certain performance
+  // hit. If the ReturnValue was not yet set, this will return the undefined
+  // value.
+  V8_INLINE Local<Value> Get() const;
+
+ private:
+  template<class F> friend class ReturnValue;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  template <class F, class G, class H>
+  friend class PersistentValueMapBase;
+  V8_INLINE void SetInternal(internal::Object* value) { *value_ = value; }
+  V8_INLINE internal::Object* GetDefaultValue();
+  V8_INLINE explicit ReturnValue(internal::Object** slot);
+  internal::Object** value_;
+};
+
+
+/**
+ * The argument information given to function call callbacks.  This
+ * class provides access to information about the context of the call,
+ * including the receiver, the number and values of arguments, and
+ * the holder of the function.
+ */
+template<typename T>
+class FunctionCallbackInfo {
+ public:
+  /** The number of available arguments. */
+  V8_INLINE int Length() const;
+  /** Accessor for the available arguments. */
+  V8_INLINE Local<Value> operator[](int i) const;
+  V8_INLINE V8_DEPRECATED("Use Data() to explicitly pass Callee instead",
+                          Local<Function> Callee() const);
+  /** Returns the receiver. This corresponds to the "this" value. */
+  V8_INLINE Local<Object> This() const;
+  /**
+   * If the callback was created without a Signature, this is the same
+   * value as This(). If there is a signature, and the signature didn't match
+   * This() but one of its hidden prototypes, this will be the respective
+   * hidden prototype.
+   *
+   * Note that this is not the prototype of This() on which the accessor
+   * referencing this callback was found (which in V8 internally is often
+   * referred to as holder [sic]).
+   */
+  V8_INLINE Local<Object> Holder() const;
+  /** For construct calls, this returns the "new.target" value. */
+  V8_INLINE Local<Value> NewTarget() const;
+  /** Indicates whether this is a regular call or a construct call. */
+  V8_INLINE bool IsConstructCall() const;
+  /** The data argument specified when creating the callback. */
+  V8_INLINE Local<Value> Data() const;
+  /** The current Isolate. */
+  V8_INLINE Isolate* GetIsolate() const;
+  /** The ReturnValue for the call. */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 8;
+
+ protected:
+  friend class internal::FunctionCallbackArguments;
+  friend class internal::CustomArguments<FunctionCallbackInfo>;
+  friend class debug::ConsoleCallArguments;
+  static const int kHolderIndex = 0;
+  static const int kIsolateIndex = 1;
+  static const int kReturnValueDefaultValueIndex = 2;
+  static const int kReturnValueIndex = 3;
+  static const int kDataIndex = 4;
+  static const int kCalleeIndex = 5;
+  static const int kContextSaveIndex = 6;
+  static const int kNewTargetIndex = 7;
+
+  V8_INLINE FunctionCallbackInfo(internal::Object** implicit_args,
+                                 internal::Object** values, int length);
+  internal::Object** implicit_args_;
+  internal::Object** values_;
+  int length_;
+};
+
+
+/**
+ * The information passed to a property callback about the context
+ * of the property access.
+ */
+template<typename T>
+class PropertyCallbackInfo {
+ public:
+  /**
+   * \return The isolate of the property access.
+   */
+  V8_INLINE Isolate* GetIsolate() const;
+
+  /**
+   * \return The data set in the configuration, i.e., in
+   * `NamedPropertyHandlerConfiguration` or
+   * `IndexedPropertyHandlerConfiguration.`
+   */
+  V8_INLINE Local<Value> Data() const;
+
+  /**
+   * \return The receiver. In many cases, this is the object on which the
+   * property access was intercepted. When using
+   * `Reflect.get`, `Function.prototype.call`, or similar functions, it is the
+   * object passed in as receiver or thisArg.
+   *
+   * \code
+   *  void GetterCallback(Local<Name> name,
+   *                      const v8::PropertyCallbackInfo<v8::Value>& info) {
+   *     auto context = info.GetIsolate()->GetCurrentContext();
+   *
+   *     v8::Local<v8::Value> a_this =
+   *         info.This()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *     v8::Local<v8::Value> a_holder =
+   *         info.Holder()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *
+   *    CHECK(v8_str("r")->Equals(context, a_this).FromJust());
+   *    CHECK(v8_str("obj")->Equals(context, a_holder).FromJust());
+   *
+   *    info.GetReturnValue().Set(name);
+   *  }
+   *
+   *  v8::Local<v8::FunctionTemplate> templ =
+   *  v8::FunctionTemplate::New(isolate);
+   *  templ->InstanceTemplate()->SetHandler(
+   *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+   *  LocalContext env;
+   *  env->Global()
+   *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+   *                                           .ToLocalChecked()
+   *                                           ->NewInstance(env.local())
+   *                                           .ToLocalChecked())
+   *      .FromJust();
+   *
+   *  CompileRun("obj.a = 'obj'; var r = {a: 'r'}; Reflect.get(obj, 'x', r)");
+   * \endcode
+   */
+  V8_INLINE Local<Object> This() const;
+
+  /**
+   * \return The object in the prototype chain of the receiver that has the
+   * interceptor. Suppose you have `x` and its prototype is `y`, and `y`
+   * has an interceptor. Then `info.This()` is `x` and `info.Holder()` is `y`.
+   * The Holder() could be a hidden object (the global object, rather
+   * than the global proxy).
+   *
+   * \note For security reasons, do not pass the object back into the runtime.
+   */
+  V8_INLINE Local<Object> Holder() const;
+
+  /**
+   * \return The return value of the callback.
+   * Can be changed by calling Set().
+   * \code
+   * info.GetReturnValue().Set(...)
+   * \endcode
+   *
+   */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+
+  /**
+   * \return True if the intercepted function should throw if an error occurs.
+   * Usually, `true` corresponds to `'use strict'`.
+   *
+   * \note Always `false` when intercepting `Reflect.set()`
+   * independent of the language mode.
+   */
+  V8_INLINE bool ShouldThrowOnError() const;
+
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 7;
+
+ protected:
+  friend class MacroAssembler;
+  friend class internal::PropertyCallbackArguments;
+  friend class internal::CustomArguments<PropertyCallbackInfo>;
+  static const int kShouldThrowOnErrorIndex = 0;
+  static const int kHolderIndex = 1;
+  static const int kIsolateIndex = 2;
+  static const int kReturnValueDefaultValueIndex = 3;
+  static const int kReturnValueIndex = 4;
+  static const int kDataIndex = 5;
+  static const int kThisIndex = 6;
+
+  V8_INLINE PropertyCallbackInfo(internal::Object** args) : args_(args) {}
+  internal::Object** args_;
+};
+
+
+typedef void (*FunctionCallback)(const FunctionCallbackInfo<Value>& info);
+
+enum class ConstructorBehavior { kThrow, kAllow };
+
+/**
+ * A JavaScript function object (ECMA-262, 15.3).
+ */
+class V8_EXPORT Function : public Object {
+ public:
+  /**
+   * Create a function in the current execution context
+   * for a given FunctionCallback.
+   */
+  static MaybeLocal<Function> New(
+      Local<Context> context, FunctionCallback callback,
+      Local<Value> data = Local<Value>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Function> New(Isolate* isolate, FunctionCallback callback,
+                          Local<Value> data = Local<Value>(), int length = 0));
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Object> NewInstance(int argc, Local<Value> argv[]) const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context, int argc, Local<Value> argv[]) const;
+
+  V8_DEPRECATED("Use maybe version", Local<Object> NewInstance() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context) const {
+    return NewInstance(context, 0, nullptr);
+  }
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Value> Call(Local<Value> recv, int argc,
+                                      Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Call(Local<Context> context,
+                                               Local<Value> recv, int argc,
+                                               Local<Value> argv[]);
+
+  void SetName(Local<String> name);
+  Local<Value> GetName() const;
+
+  /**
+   * Name inferred from variable or property assignment of this function.
+   * Used to facilitate debugging and profiling of JavaScript code written
+   * in an OO style, where many functions are anonymous but are assigned
+   * to object properties.
+   */
+  Local<Value> GetInferredName() const;
+
+  /**
+   * displayName if it is set, otherwise name if it is configured, otherwise
+   * function name, otherwise inferred name.
+   */
+  Local<Value> GetDebugName() const;
+
+  /**
+   * User-defined name assigned to the "displayName" property of this function.
+   * Used to facilitate debugging and profiling of JavaScript code.
+   */
+  Local<Value> GetDisplayName() const;
+
+  /**
+   * Returns zero based line number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptLineNumber() const;
+  /**
+   * Returns zero based column number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptColumnNumber() const;
+
+  /**
+   * Tells whether this function is builtin.
+   */
+  V8_DEPRECATED("this should no longer be used.", bool IsBuiltin() const);
+
+  /**
+   * Returns scriptId.
+   */
+  int ScriptId() const;
+
+  /**
+   * Returns the original function if this function is bound, else returns
+   * v8::Undefined.
+   */
+  Local<Value> GetBoundFunction() const;
+
+  ScriptOrigin GetScriptOrigin() const;
+  V8_INLINE static Function* Cast(Value* obj);
+  static const int kLineOffsetNotFound;
+
+ private:
+  Function();
+  static void CheckCast(Value* obj);
+};
+
+#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
+#endif
+
+/**
+ * An instance of the built-in Promise constructor (ES6 draft).
+ */
+class V8_EXPORT Promise : public Object {
+ public:
+  /**
+   * State of the promise. Each value corresponds to one of the possible values
+   * of the [[PromiseState]] field.
+   */
+  enum PromiseState { kPending, kFulfilled, kRejected };
+
+  class V8_EXPORT Resolver : public Object {
+   public:
+    /**
+     * Create a new resolver, along with an associated promise in pending state.
+     */
+    static V8_DEPRECATE_SOON("Use maybe version",
+                             Local<Resolver> New(Isolate* isolate));
+    static V8_WARN_UNUSED_RESULT MaybeLocal<Resolver> New(
+        Local<Context> context);
+
+    /**
+     * Extract the associated promise.
+     */
+    Local<Promise> GetPromise();
+
+    /**
+     * Resolve/reject the associated promise with a given value.
+     * Ignored if the promise is no longer pending.
+     */
+    V8_DEPRECATE_SOON("Use maybe version", void Resolve(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Resolve(Local<Context> context,
+                                              Local<Value> value);
+
+    V8_DEPRECATE_SOON("Use maybe version", void Reject(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Reject(Local<Context> context,
+                                             Local<Value> value);
+
+    V8_INLINE static Resolver* Cast(Value* obj);
+
+   private:
+    Resolver();
+    static void CheckCast(Value* obj);
+  };
+
+  /**
+   * Register a resolution/rejection handler with a promise.
+   * The handler is given the respective resolution/rejection value as
+   * an argument. If the promise is already resolved/rejected, the handler is
+   * invoked at the end of turn.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Catch(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Catch(Local<Context> context,
+                                                  Local<Function> handler);
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Then(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
+                                                 Local<Function> handler);
+
+  /**
+   * Returns true if the promise has at least one derived promise, and
+   * therefore resolve/reject handlers (including default handler).
+   */
+  bool HasHandler();
+
+  /**
+   * Returns the content of the [[PromiseResult]] field. The Promise must not
+   * be pending.
+   */
+  Local<Value> Result();
+
+  /**
+   * Returns the value of the [[PromiseState]] field.
+   */
+  PromiseState State();
+
+  V8_INLINE static Promise* Cast(Value* obj);
+
+  static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
+
+ private:
+  Promise();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of a Property Descriptor, see Ecma-262 6.2.4.
+ *
+ * Properties in a descriptor are present or absent. If you do not set
+ * `enumerable`, `configurable`, and `writable`, they are absent. If `value`,
+ * `get`, or `set` are absent, but you must specify them in the constructor, use
+ * empty handles.
+ *
+ * Accessors `get` and `set` must be callable or undefined if they are present.
+ *
+ * \note Only query properties if they are present, i.e., call `x()` only if
+ * `has_x()` returns true.
+ *
+ * \code
+ * // var desc = {writable: false}
+ * v8::PropertyDescriptor d(Local<Value>()), false);
+ * d.value(); // error, value not set
+ * if (d.has_writable()) {
+ *   d.writable(); // false
+ * }
+ *
+ * // var desc = {value: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate));
+ *
+ * // var desc = {get: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate), Local<Value>()));
+ * \endcode
+ */
+class V8_EXPORT PropertyDescriptor {
+ public:
+  // GenericDescriptor
+  PropertyDescriptor();
+
+  // DataDescriptor
+  PropertyDescriptor(Local<Value> value);
+
+  // DataDescriptor with writable property
+  PropertyDescriptor(Local<Value> value, bool writable);
+
+  // AccessorDescriptor
+  PropertyDescriptor(Local<Value> get, Local<Value> set);
+
+  ~PropertyDescriptor();
+
+  Local<Value> value() const;
+  bool has_value() const;
+
+  Local<Value> get() const;
+  bool has_get() const;
+  Local<Value> set() const;
+  bool has_set() const;
+
+  void set_enumerable(bool enumerable);
+  bool enumerable() const;
+  bool has_enumerable() const;
+
+  void set_configurable(bool configurable);
+  bool configurable() const;
+  bool has_configurable() const;
+
+  bool writable() const;
+  bool has_writable() const;
+
+  struct PrivateData;
+  PrivateData* get_private() const { return private_; }
+
+  PropertyDescriptor(const PropertyDescriptor&) = delete;
+  void operator=(const PropertyDescriptor&) = delete;
+
+ private:
+  PrivateData* private_;
+};
+
+/**
+ * An instance of the built-in Proxy constructor (ECMA-262, 6th Edition,
+ * 26.2.1).
+ */
+class V8_EXPORT Proxy : public Object {
+ public:
+  Local<Object> GetTarget();
+  Local<Value> GetHandler();
+  bool IsRevoked();
+  void Revoke();
+
+  /**
+   * Creates a new Proxy for the target object.
+   */
+  static MaybeLocal<Proxy> New(Local<Context> context,
+                               Local<Object> local_target,
+                               Local<Object> local_handler);
+
+  V8_INLINE static Proxy* Cast(Value* obj);
+
+ private:
+  Proxy();
+  static void CheckCast(Value* obj);
+};
+
+// TODO(mtrofin): rename WasmCompiledModule to WasmModuleObject, for
+// consistency with internal APIs.
+class V8_EXPORT WasmCompiledModule : public Object {
+ public:
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> SerializedModule;
+  // A buffer that is owned by the caller.
+  typedef std::pair<const uint8_t*, size_t> CallerOwnedBuffer;
+
+  // An opaque, native heap object for transferring wasm modules. It
+  // supports move semantics, and does not support copy semantics.
+  class TransferrableModule final {
+   public:
+    TransferrableModule(TransferrableModule&& src) = default;
+    TransferrableModule(const TransferrableModule& src) = delete;
+
+    TransferrableModule& operator=(TransferrableModule&& src) = default;
+    TransferrableModule& operator=(const TransferrableModule& src) = delete;
+
+   private:
+    typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> OwnedBuffer;
+    friend class WasmCompiledModule;
+    TransferrableModule(OwnedBuffer&& code, OwnedBuffer&& bytes)
+        : compiled_code(std::move(code)), wire_bytes(std::move(bytes)) {}
+
+    OwnedBuffer compiled_code = {nullptr, 0};
+    OwnedBuffer wire_bytes = {nullptr, 0};
+  };
+
+  // Get an in-memory, non-persistable, and context-independent (meaning,
+  // suitable for transfer to another Isolate and Context) representation
+  // of this wasm compiled module.
+  TransferrableModule GetTransferrableModule();
+
+  // Efficiently re-create a WasmCompiledModule, without recompiling, from
+  // a TransferrableModule.
+  static MaybeLocal<WasmCompiledModule> FromTransferrableModule(
+      Isolate* isolate, const TransferrableModule&);
+
+  // Get the wasm-encoded bytes that were used to compile this module.
+  Local<String> GetWasmWireBytes();
+
+  // Serialize the compiled module. The serialized data does not include the
+  // uncompiled bytes.
+  SerializedModule Serialize();
+
+  // If possible, deserialize the module, otherwise compile it from the provided
+  // uncompiled bytes.
+  static MaybeLocal<WasmCompiledModule> DeserializeOrCompile(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  V8_INLINE static WasmCompiledModule* Cast(Value* obj);
+
+ private:
+  // TODO(ahaas): please remove the friend once streamed compilation is
+  // implemented
+  friend class WasmModuleObjectBuilder;
+
+  static MaybeLocal<WasmCompiledModule> Deserialize(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  static MaybeLocal<WasmCompiledModule> Compile(Isolate* isolate,
+                                                const uint8_t* start,
+                                                size_t length);
+  static CallerOwnedBuffer AsCallerOwned(
+      const TransferrableModule::OwnedBuffer& buff) {
+    return {buff.first.get(), buff.second};
+  }
+
+  WasmCompiledModule();
+  static void CheckCast(Value* obj);
+};
+
+class V8_EXPORT WasmModuleObjectBuilder final {
+ public:
+  WasmModuleObjectBuilder(Isolate* isolate) : isolate_(isolate) {}
+  // The buffer passed into OnBytesReceived is owned by the caller.
+  void OnBytesReceived(const uint8_t*, size_t size);
+  MaybeLocal<WasmCompiledModule> Finish();
+
+ private:
+  Isolate* isolate_ = nullptr;
+  // TODO(ahaas): We probably need none of this below here once streamed
+  // compilation is implemented.
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> Buffer;
+
+  // Disable copy semantics *in this implementation*. We can choose to
+  // relax this, albeit it's not clear why.
+  WasmModuleObjectBuilder(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder(WasmModuleObjectBuilder&&) = default;
+  WasmModuleObjectBuilder& operator=(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder& operator=(WasmModuleObjectBuilder&&) = default;
+
+  std::vector<Buffer> received_buffers_;
+  size_t total_size_ = 0;
+};
+
+#ifndef V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+enum class ArrayBufferCreationMode { kInternalized, kExternalized };
+
+
+/**
+ * An instance of the built-in ArrayBuffer constructor (ES6 draft 15.13.5).
+ */
+class V8_EXPORT ArrayBuffer : public Object {
+ public:
+  /**
+   * A thread-safe allocator that V8 uses to allocate |ArrayBuffer|'s memory.
+   * The allocator is a global V8 setting. It has to be set via
+   * Isolate::CreateParams.
+   *
+   * Memory allocated through this allocator by V8 is accounted for as external
+   * memory by V8. Note that V8 keeps track of the memory for all internalized
+   * |ArrayBuffer|s. Responsibility for tracking external memory (using
+   * Isolate::AdjustAmountOfExternalAllocatedMemory) is handed over to the
+   * embedder upon externalization and taken over upon internalization (creating
+   * an internalized buffer from an existing buffer).
+   *
+   * Note that it is unsafe to call back into V8 from any of the allocator
+   * functions.
+   */
+  class V8_EXPORT Allocator { // NOLINT
+   public:
+    virtual ~Allocator() {}
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory should be initialized to zeroes.
+     */
+    virtual void* Allocate(size_t length) = 0;
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory does not have to be initialized.
+     */
+    virtual void* AllocateUninitialized(size_t length) = 0;
+
+    /**
+     * Reserved |length| bytes, but do not commit the memory. Must call
+     * |SetProtection| to make memory accessible.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void* Reserve(size_t length);
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate|.
+     */
+    virtual void Free(void* data, size_t length) = 0;
+
+    enum class AllocationMode { kNormal, kReservation };
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate| or
+     * |Reserve|, depending on |mode|.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void Free(void* data, size_t length, AllocationMode mode);
+
+    enum class Protection { kNoAccess, kReadWrite };
+
+    /**
+     * Change the protection on a region of memory.
+     *
+     * On platforms that make a distinction between reserving and committing
+     * memory, changing the protection to kReadWrite must also ensure the memory
+     * is committed.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void SetProtection(void* data, size_t length,
+                               Protection protection);
+
+    /**
+     * malloc/free based convenience allocator.
+     *
+     * Caller takes ownership, i.e. the returned object needs to be freed using
+     * |delete allocator| once it is no longer in use.
+     */
+    static Allocator* NewDefaultAllocator();
+  };
+
+  /**
+   * The contents of an |ArrayBuffer|. Externalization of |ArrayBuffer|
+   * returns an instance of this class, populated, with a pointer to data
+   * and byte length.
+   *
+   * The Data pointer of ArrayBuffer::Contents is always allocated with
+   * Allocator::Allocate that is set via Isolate::CreateParams.
+   */
+  class V8_EXPORT Contents { // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class ArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new ArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created ArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<ArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new ArrayBuffer over an existing memory block.
+   * The created array buffer is by default immediately in externalized state.
+   * In externalized state, the memory block will not be reclaimed when a
+   * created ArrayBuffer is garbage-collected.
+   * In internalized state, the memory block will be released using
+   * |Allocator::Free| once all ArrayBuffers referencing it are collected by
+   * the garbage collector.
+   */
+  static Local<ArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if ArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this ArrayBuffer may be neutered.
+   */
+  bool IsNeuterable() const;
+
+  /**
+   * Neuters this ArrayBuffer and all its views (typed arrays).
+   * Neutering sets the byte length of the buffer and all typed arrays to zero,
+   * preventing JavaScript from ever accessing underlying backing store.
+   * ArrayBuffer should have been externalized and must be neuterable.
+   */
+  void Neuter();
+
+  /**
+   * Make this ArrayBuffer external. The pointer to underlying memory block
+   * and byte length are returned as |Contents| structure. After ArrayBuffer
+   * had been externalized, it does no longer own the memory block. The caller
+   * should take steps to free memory when it is no longer needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * that has been set via Isolate::CreateParams.
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer gets garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|.
+   */
+  Contents GetContents();
+
+  V8_INLINE static ArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+#ifndef V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+/**
+ * A base class for an instance of one of "views" over ArrayBuffer,
+ * including TypedArrays and DataView (ES6 draft 15.13).
+ */
+class V8_EXPORT ArrayBufferView : public Object {
+ public:
+  /**
+   * Returns underlying ArrayBuffer.
+   */
+  Local<ArrayBuffer> Buffer();
+  /**
+   * Byte offset in |Buffer|.
+   */
+  size_t ByteOffset();
+  /**
+   * Size of a view in bytes.
+   */
+  size_t ByteLength();
+
+  /**
+   * Copy the contents of the ArrayBufferView's buffer to an embedder defined
+   * memory without additional overhead that calling ArrayBufferView::Buffer
+   * might incur.
+   *
+   * Will write at most min(|byte_length|, ByteLength) bytes starting at
+   * ByteOffset of the underlying buffer to the memory starting at |dest|.
+   * Returns the number of bytes actually written.
+   */
+  size_t CopyContents(void* dest, size_t byte_length);
+
+  /**
+   * Returns true if ArrayBufferView's backing ArrayBuffer has already been
+   * allocated.
+   */
+  bool HasBuffer() const;
+
+  V8_INLINE static ArrayBufferView* Cast(Value* obj);
+
+  static const int kInternalFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBufferView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A base class for an instance of TypedArray series of constructors
+ * (ES6 draft 15.13.6).
+ */
+class V8_EXPORT TypedArray : public ArrayBufferView {
+ public:
+  /**
+   * Number of elements in this typed array
+   * (e.g. for Int16Array, |ByteLength|/2).
+   */
+  size_t Length();
+
+  V8_INLINE static TypedArray* Cast(Value* obj);
+
+ private:
+  TypedArray();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8Array : public TypedArray {
+ public:
+  static Local<Uint8Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Uint8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Uint8Array* Cast(Value* obj);
+
+ private:
+  Uint8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8ClampedArray constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8ClampedArray : public TypedArray {
+ public:
+  static Local<Uint8ClampedArray> New(Local<ArrayBuffer> array_buffer,
+                                      size_t byte_offset, size_t length);
+  static Local<Uint8ClampedArray> New(
+      Local<SharedArrayBuffer> shared_array_buffer, size_t byte_offset,
+      size_t length);
+  V8_INLINE static Uint8ClampedArray* Cast(Value* obj);
+
+ private:
+  Uint8ClampedArray();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of Int8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int8Array : public TypedArray {
+ public:
+  static Local<Int8Array> New(Local<ArrayBuffer> array_buffer,
+                              size_t byte_offset, size_t length);
+  static Local<Int8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                              size_t byte_offset, size_t length);
+  V8_INLINE static Int8Array* Cast(Value* obj);
+
+ private:
+  Int8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint16Array : public TypedArray {
+ public:
+  static Local<Uint16Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint16Array* Cast(Value* obj);
+
+ private:
+  Uint16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int16Array : public TypedArray {
+ public:
+  static Local<Int16Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int16Array* Cast(Value* obj);
+
+ private:
+  Int16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint32Array : public TypedArray {
+ public:
+  static Local<Uint32Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint32Array* Cast(Value* obj);
+
+ private:
+  Uint32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int32Array : public TypedArray {
+ public:
+  static Local<Int32Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int32Array* Cast(Value* obj);
+
+ private:
+  Int32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float32Array : public TypedArray {
+ public:
+  static Local<Float32Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float32Array* Cast(Value* obj);
+
+ private:
+  Float32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float64Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float64Array : public TypedArray {
+ public:
+  static Local<Float64Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float64Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float64Array* Cast(Value* obj);
+
+ private:
+  Float64Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of DataView constructor (ES6 draft 15.13.7).
+ */
+class V8_EXPORT DataView : public ArrayBufferView {
+ public:
+  static Local<DataView> New(Local<ArrayBuffer> array_buffer,
+                             size_t byte_offset, size_t length);
+  static Local<DataView> New(Local<SharedArrayBuffer> shared_array_buffer,
+                             size_t byte_offset, size_t length);
+  V8_INLINE static DataView* Cast(Value* obj);
+
+ private:
+  DataView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in SharedArrayBuffer constructor.
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedArrayBuffer : public Object {
+ public:
+  /**
+   * The contents of an |SharedArrayBuffer|. Externalization of
+   * |SharedArrayBuffer| returns an instance of this class, populated, with a
+   * pointer to data and byte length.
+   *
+   * The Data pointer of SharedArrayBuffer::Contents is always allocated with
+   * |ArrayBuffer::Allocator::Allocate| by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   * This API is experimental and may change significantly.
+   */
+  class V8_EXPORT Contents {  // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class SharedArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new SharedArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created SharedArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<SharedArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new SharedArrayBuffer over an existing memory block.  The created
+   * array buffer is immediately in externalized state unless otherwise
+   * specified. The memory block will not be reclaimed when a created
+   * SharedArrayBuffer is garbage-collected.
+   */
+  static Local<SharedArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if SharedArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Make this SharedArrayBuffer external. The pointer to underlying memory
+   * block and byte length are returned as |Contents| structure. After
+   * SharedArrayBuffer had been externalized, it does no longer own the memory
+   * block. The caller should take steps to free memory when it is no longer
+   * needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer became garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   */
+  Contents GetContents();
+
+  V8_INLINE static SharedArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  SharedArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Date constructor (ECMA-262, 15.9).
+ */
+class V8_EXPORT Date : public Object {
+ public:
+  static V8_DEPRECATE_SOON("Use maybe version.",
+                           Local<Value> New(Isolate* isolate, double time));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> New(Local<Context> context,
+                                                     double time);
+
+  /**
+   * A specialization of Value::NumberValue that is more efficient
+   * because we know the structure of this object.
+   */
+  double ValueOf() const;
+
+  V8_INLINE static Date* Cast(Value* obj);
+
+  /**
+   * Notification that the embedder has changed the time zone,
+   * daylight savings time, or other date / time configuration
+   * parameters.  V8 keeps a cache of various values used for
+   * date / time computation.  This notification will reset
+   * those cached values for the current context so that date /
+   * time configuration changes would be reflected in the Date
+   * object.
+   *
+   * This API should not be called more than needed as it will
+   * negatively impact the performance of date operations.
+   */
+  static void DateTimeConfigurationChangeNotification(Isolate* isolate);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Number object (ECMA-262, 4.3.21).
+ */
+class V8_EXPORT NumberObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, double value);
+
+  double ValueOf() const;
+
+  V8_INLINE static NumberObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Boolean object (ECMA-262, 4.3.15).
+ */
+class V8_EXPORT BooleanObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, bool value);
+  V8_DEPRECATED("Pass an isolate", static Local<Value> New(bool value));
+
+  bool ValueOf() const;
+
+  V8_INLINE static BooleanObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A String object (ECMA-262, 4.3.18).
+ */
+class V8_EXPORT StringObject : public Object {
+ public:
+  static Local<Value> New(Local<String> value);
+
+  Local<String> ValueOf() const;
+
+  V8_INLINE static StringObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Symbol object (ECMA-262 edition 6).
+ */
+class V8_EXPORT SymbolObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, Local<Symbol> value);
+
+  Local<Symbol> ValueOf() const;
+
+  V8_INLINE static SymbolObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in RegExp constructor (ECMA-262, 15.10).
+ */
+class V8_EXPORT RegExp : public Object {
+ public:
+  /**
+   * Regular expression flag bits. They can be or'ed to enable a set
+   * of flags.
+   */
+  enum Flags {
+    kNone = 0,
+    kGlobal = 1 << 0,
+    kIgnoreCase = 1 << 1,
+    kMultiline = 1 << 2,
+    kSticky = 1 << 3,
+    kUnicode = 1 << 4,
+    kDotAll = 1 << 5,
+  };
+
+  /**
+   * Creates a regular expression from the given pattern string and
+   * the flags bit field. May throw a JavaScript exception as
+   * described in ECMA-262, 15.10.4.1.
+   *
+   * For example,
+   *   RegExp::New(v8::String::New("foo"),
+   *               static_cast<RegExp::Flags>(kGlobal | kMultiline))
+   * is equivalent to evaluating "/foo/gm".
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<RegExp> New(Local<String> pattern,
+                                             Flags flags));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<RegExp> New(Local<Context> context,
+                                                      Local<String> pattern,
+                                                      Flags flags);
+
+  /**
+   * Returns the value of the source property: a string representing
+   * the regular expression.
+   */
+  Local<String> GetSource() const;
+
+  /**
+   * Returns the flags bit field.
+   */
+  Flags GetFlags() const;
+
+  V8_INLINE static RegExp* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A JavaScript value that wraps a C++ void*. This type of value is mainly used
+ * to associate C++ data structures with JavaScript objects.
+ */
+class V8_EXPORT External : public Value {
+ public:
+  static Local<External> New(Isolate* isolate, void* value);
+  V8_INLINE static External* Cast(Value* obj);
+  void* Value() const;
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+#define V8_INTRINSICS_LIST(F)                    \
+  F(ArrayProto_entries, array_entries_iterator)  \
+  F(ArrayProto_forEach, array_for_each_iterator) \
+  F(ArrayProto_keys, array_keys_iterator)        \
+  F(ArrayProto_values, array_values_iterator)    \
+  F(IteratorPrototype, initial_iterator_prototype)
+
+enum Intrinsic {
+#define V8_DECL_INTRINSIC(name, iname) k##name,
+  V8_INTRINSICS_LIST(V8_DECL_INTRINSIC)
+#undef V8_DECL_INTRINSIC
+};
+
+
+// --- Templates ---
+
+
+/**
+ * The superclass of object and function templates.
+ */
+class V8_EXPORT Template : public Data {
+ public:
+  /**
+   * Adds a property to each instance created by this template.
+   *
+   * The property must be defined either as a primitive value, or a template.
+   */
+  void Set(Local<Name> name, Local<Data> value,
+           PropertyAttribute attributes = None);
+  void SetPrivate(Local<Private> name, Local<Data> value,
+                  PropertyAttribute attributes = None);
+  V8_INLINE void Set(Isolate* isolate, const char* name, Local<Data> value);
+
+  void SetAccessorProperty(
+     Local<Name> name,
+     Local<FunctionTemplate> getter = Local<FunctionTemplate>(),
+     Local<FunctionTemplate> setter = Local<FunctionTemplate>(),
+     PropertyAttribute attribute = None,
+     AccessControl settings = DEFAULT);
+
+  /**
+   * Whenever the property with the given name is accessed on objects
+   * created from this Template the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetNativeDataProperty(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+  void SetNativeDataProperty(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+
+  /**
+   * Like SetNativeDataProperty, but V8 will replace the native data property
+   * with a real data property on first access.
+   */
+  void SetLazyDataProperty(Local<Name> name, AccessorNameGetterCallback getter,
+                           Local<Value> data = Local<Value>(),
+                           PropertyAttribute attribute = None);
+
+  /**
+   * During template instantiation, sets the value with the intrinsic property
+   * from the correct context.
+   */
+  void SetIntrinsicDataProperty(Local<Name> name, Intrinsic intrinsic,
+                                PropertyAttribute attribute = None);
+
+ private:
+  Template();
+
+  friend class ObjectTemplate;
+  friend class FunctionTemplate;
+};
+
+
+/**
+ * NamedProperty[Getter|Setter] are used as interceptors on object.
+ * See ObjectTemplate::SetNamedPropertyHandler.
+ */
+typedef void (*NamedPropertyGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns the value if the setter intercepts the request.
+ * Otherwise, returns an empty handle.
+ */
+typedef void (*NamedPropertySetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns a non-empty handle if the interceptor intercepts the request.
+ * The result is an integer encoding property attributes (like v8::None,
+ * v8::DontEnum, etc.)
+ */
+typedef void (*NamedPropertyQueryCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Integer>& info);
+
+
+/**
+ * Returns a non-empty handle if the deleter intercepts the request.
+ * The return value is true if the property could be deleted and false
+ * otherwise.
+ */
+typedef void (*NamedPropertyDeleterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*NamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+
+// TODO(dcarney): Deprecate and remove previous typedefs, and replace
+// GenericNamedPropertyFooCallback with just NamedPropertyFooCallback.
+
+/**
+ * Interceptor for get requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted get request.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict`' mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \code
+ *  void GetterCallback(
+ *    Local<Name> name,
+ *    const v8::PropertyCallbackInfo<v8::Value>& info) {
+ *      info.GetReturnValue().Set(v8_num(42));
+ *  }
+ *
+ *  v8::Local<v8::FunctionTemplate> templ =
+ *      v8::FunctionTemplate::New(isolate);
+ *  templ->InstanceTemplate()->SetHandler(
+ *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+ *  LocalContext env;
+ *  env->Global()
+ *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+ *                                             .ToLocalChecked()
+ *                                             ->NewInstance(env.local())
+ *                                             .ToLocalChecked())
+ *      .FromJust();
+ *  v8::Local<v8::Value> result = CompileRun("obj.a = 17; obj.a");
+ *  CHECK(v8_num(42)->Equals(env.local(), result).FromJust());
+ * \endcode
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyGetterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for set requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the setter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the setter
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param value The value which the property will have if the request
+ * is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertySetterCallback)(
+    Local<Name> property, Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Intercepts all requests that query the attributes of the
+ * property, e.g., getOwnPropertyDescriptor(), propertyIsEnumerable(), and
+ * defineProperty().
+ *
+ * Use `info.GetReturnValue().Set(value)` to set the property attributes. The
+ * value is an interger encoding a `v8::PropertyAttribute`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note Some functions query the property attributes internally, even though
+ * they do not return the attributes. For example, `hasOwnProperty()` can
+ * trigger this interceptor depending on the state of the object.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyQueryCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * Interceptor for delete requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the deleter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)` with a boolean `value`. The `value` is
+ * used as the return value of `delete`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If you need to mimic the behavior of `delete`, i.e., throw in strict
+ * mode instead of returning false, use `info.ShouldThrowOnError()` to determine
+ * if you are in strict mode.
+ *
+ * See also `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyDeleterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*GenericNamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * Interceptor for defineProperty requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the definer successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the definer
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param desc The property descriptor which is used to define the
+ * property if the request is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDefinerCallback)(
+    Local<Name> property, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for getOwnPropertyDescriptor requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted request. The return value must be an object that
+ * can be converted to a PropertyDescriptor, e.g., a `v8::value` returned from
+ * `v8::Object::getOwnPropertyDescriptor`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If GetOwnPropertyDescriptor is intercepted, it will
+ * always return true, i.e., indicate that the property was found.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDescriptorCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyGetterCallback`.
+ */
+typedef void (*IndexedPropertyGetterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertySetterCallback`.
+ */
+typedef void (*IndexedPropertySetterCallback)(
+    uint32_t index,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyQueryCallback`.
+ */
+typedef void (*IndexedPropertyQueryCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDeleterCallback`.
+ */
+typedef void (*IndexedPropertyDeleterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Boolean>& info);
+
+/**
+ * See `v8::GenericNamedPropertyEnumeratorCallback`.
+ */
+typedef void (*IndexedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDefinerCallback`.
+ */
+typedef void (*IndexedPropertyDefinerCallback)(
+    uint32_t index, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDescriptorCallback`.
+ */
+typedef void (*IndexedPropertyDescriptorCallback)(
+    uint32_t index, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Access type specification.
+ */
+enum AccessType {
+  ACCESS_GET,
+  ACCESS_SET,
+  ACCESS_HAS,
+  ACCESS_DELETE,
+  ACCESS_KEYS
+};
+
+
+/**
+ * Returns true if the given context should be allowed to access the given
+ * object.
+ */
+typedef bool (*AccessCheckCallback)(Local<Context> accessing_context,
+                                    Local<Object> accessed_object,
+                                    Local<Value> data);
+
+/**
+ * A FunctionTemplate is used to create functions at runtime. There
+ * can only be one function created from a FunctionTemplate in a
+ * context.  The lifetime of the created function is equal to the
+ * lifetime of the context.  So in case the embedder needs to create
+ * temporary functions that can be collected using Scripts is
+ * preferred.
+ *
+ * Any modification of a FunctionTemplate after first instantiation will trigger
+ * a crash.
+ *
+ * A FunctionTemplate can have properties, these properties are added to the
+ * function object when it is created.
+ *
+ * A FunctionTemplate has a corresponding instance template which is
+ * used to create object instances when the function is used as a
+ * constructor. Properties added to the instance template are added to
+ * each object instance.
+ *
+ * A FunctionTemplate can have a prototype template. The prototype template
+ * is used to create the prototype object of the function.
+ *
+ * The following example shows how to use a FunctionTemplate:
+ *
+ * \code
+ *    v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(isolate);
+ *    t->Set(isolate, "func_property", v8::Number::New(isolate, 1));
+ *
+ *    v8::Local<v8::Template> proto_t = t->PrototypeTemplate();
+ *    proto_t->Set(isolate,
+ *                 "proto_method",
+ *                 v8::FunctionTemplate::New(isolate, InvokeCallback));
+ *    proto_t->Set(isolate, "proto_const", v8::Number::New(isolate, 2));
+ *
+ *    v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
+ *    instance_t->SetAccessor(String::NewFromUtf8(isolate, "instance_accessor"),
+ *                            InstanceAccessorCallback);
+ *    instance_t->SetNamedPropertyHandler(PropertyHandlerCallback);
+ *    instance_t->Set(String::NewFromUtf8(isolate, "instance_property"),
+ *                    Number::New(isolate, 3));
+ *
+ *    v8::Local<v8::Function> function = t->GetFunction();
+ *    v8::Local<v8::Object> instance = function->NewInstance();
+ * \endcode
+ *
+ * Let's use "function" as the JS variable name of the function object
+ * and "instance" for the instance object created above.  The function
+ * and the instance will have the following properties:
+ *
+ * \code
+ *   func_property in function == true;
+ *   function.func_property == 1;
+ *
+ *   function.prototype.proto_method() invokes 'InvokeCallback'
+ *   function.prototype.proto_const == 2;
+ *
+ *   instance instanceof function == true;
+ *   instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   instance.instance_property == 3;
+ * \endcode
+ *
+ * A FunctionTemplate can inherit from another one by calling the
+ * FunctionTemplate::Inherit method.  The following graph illustrates
+ * the semantics of inheritance:
+ *
+ * \code
+ *   FunctionTemplate Parent  -> Parent() . prototype -> { }
+ *     ^                                                  ^
+ *     | Inherit(Parent)                                  | .__proto__
+ *     |                                                  |
+ *   FunctionTemplate Child   -> Child()  . prototype -> { }
+ * \endcode
+ *
+ * A FunctionTemplate 'Child' inherits from 'Parent', the prototype
+ * object of the Child() function has __proto__ pointing to the
+ * Parent() function's prototype object. An instance of the Child
+ * function has all properties on Parent's instance templates.
+ *
+ * Let Parent be the FunctionTemplate initialized in the previous
+ * section and create a Child FunctionTemplate by:
+ *
+ * \code
+ *   Local<FunctionTemplate> parent = t;
+ *   Local<FunctionTemplate> child = FunctionTemplate::New();
+ *   child->Inherit(parent);
+ *
+ *   Local<Function> child_function = child->GetFunction();
+ *   Local<Object> child_instance = child_function->NewInstance();
+ * \endcode
+ *
+ * The Child function and Child instance will have the following
+ * properties:
+ *
+ * \code
+ *   child_func.prototype.__proto__ == function.prototype;
+ *   child_instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   child_instance.instance_property == 3;
+ * \endcode
+ */
+class V8_EXPORT FunctionTemplate : public Template {
+ public:
+  /** Creates a function template.*/
+  static Local<FunctionTemplate> New(
+      Isolate* isolate, FunctionCallback callback = 0,
+      Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<FunctionTemplate> FromSnapshot(Isolate* isolate,
+                                                   size_t index);
+
+  /**
+   * Creates a function template backed/cached by a private property.
+   */
+  static Local<FunctionTemplate> NewWithCache(
+      Isolate* isolate, FunctionCallback callback,
+      Local<Private> cache_property, Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0);
+
+  /** Returns the unique function instance in the current execution context.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Function> GetFunction());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Function> GetFunction(
+      Local<Context> context);
+
+  /**
+   * Similar to Context::NewRemoteContext, this creates an instance that
+   * isn't backed by an actual object.
+   *
+   * The InstanceTemplate of this FunctionTemplate must have access checks with
+   * handlers installed.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewRemoteInstance();
+
+  /**
+   * Set the call-handler callback for a FunctionTemplate.  This
+   * callback is called whenever the function created from this
+   * FunctionTemplate is called.
+   */
+  void SetCallHandler(FunctionCallback callback,
+                      Local<Value> data = Local<Value>());
+
+  /** Set the predefined length property for the FunctionTemplate. */
+  void SetLength(int length);
+
+  /** Get the InstanceTemplate. */
+  Local<ObjectTemplate> InstanceTemplate();
+
+  /**
+   * Causes the function template to inherit from a parent function template.
+   * This means the the function's prototype.__proto__ is set to the parent
+   * function's prototype.
+   **/
+  void Inherit(Local<FunctionTemplate> parent);
+
+  /**
+   * A PrototypeTemplate is the template used to create the prototype object
+   * of the function created by this template.
+   */
+  Local<ObjectTemplate> PrototypeTemplate();
+
+  /**
+   * A PrototypeProviderTemplate is another function template whose prototype
+   * property is used for this template. This is mutually exclusive with setting
+   * a prototype template indirectly by calling PrototypeTemplate() or using
+   * Inherit().
+   **/
+  void SetPrototypeProviderTemplate(Local<FunctionTemplate> prototype_provider);
+
+  /**
+   * Set the class name of the FunctionTemplate.  This is used for
+   * printing objects created with the function created from the
+   * FunctionTemplate as its constructor.
+   */
+  void SetClassName(Local<String> name);
+
+
+  /**
+   * When set to true, no access check will be performed on the receiver of a
+   * function call.  Currently defaults to true, but this is subject to change.
+   */
+  void SetAcceptAnyReceiver(bool value);
+
+  /**
+   * Determines whether the __proto__ accessor ignores instances of
+   * the function template.  If instances of the function template are
+   * ignored, __proto__ skips all instances and instead returns the
+   * next object in the prototype chain.
+   *
+   * Call with a value of true to make the __proto__ accessor ignore
+   * instances of the function template.  Call with a value of false
+   * to make the __proto__ accessor not ignore instances of the
+   * function template.  By default, instances of a function template
+   * are not ignored.
+   */
+  void SetHiddenPrototype(bool value);
+
+  /**
+   * Sets the ReadOnly flag in the attributes of the 'prototype' property
+   * of functions created from this FunctionTemplate to true.
+   */
+  void ReadOnlyPrototype();
+
+  /**
+   * Removes the prototype property from functions created from this
+   * FunctionTemplate.
+   */
+  void RemovePrototype();
+
+  /**
+   * Returns true if the given object is an instance of this function
+   * template.
+   */
+  bool HasInstance(Local<Value> object);
+
+ private:
+  FunctionTemplate();
+  friend class Context;
+  friend class ObjectTemplate;
+};
+
+/**
+ * Configuration flags for v8::NamedPropertyHandlerConfiguration or
+ * v8::IndexedPropertyHandlerConfiguration.
+ */
+enum class PropertyHandlerFlags {
+  /**
+   * None.
+   */
+  kNone = 0,
+
+  /**
+   * See ALL_CAN_READ above.
+   */
+  kAllCanRead = 1,
+
+  /** Will not call into interceptor for properties on the receiver or prototype
+   * chain, i.e., only call into interceptor for properties that do not exist.
+   * Currently only valid for named interceptors.
+   */
+  kNonMasking = 1 << 1,
+
+  /**
+   * Will not call into interceptor for symbol lookup.  Only meaningful for
+   * named interceptors.
+   */
+  kOnlyInterceptStrings = 1 << 2,
+};
+
+struct NamedPropertyHandlerConfiguration {
+  NamedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      GenericNamedPropertyGetterCallback getter = 0,
+      GenericNamedPropertySetterCallback setter = 0,
+      GenericNamedPropertyQueryCallback query = 0,
+      GenericNamedPropertyDeleterCallback deleter = 0,
+      GenericNamedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  NamedPropertyHandlerConfiguration(
+      GenericNamedPropertyGetterCallback getter,
+      GenericNamedPropertySetterCallback setter,
+      GenericNamedPropertyDescriptorCallback descriptor,
+      GenericNamedPropertyDeleterCallback deleter,
+      GenericNamedPropertyEnumeratorCallback enumerator,
+      GenericNamedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  GenericNamedPropertyGetterCallback getter;
+  GenericNamedPropertySetterCallback setter;
+  GenericNamedPropertyQueryCallback query;
+  GenericNamedPropertyDeleterCallback deleter;
+  GenericNamedPropertyEnumeratorCallback enumerator;
+  GenericNamedPropertyDefinerCallback definer;
+  GenericNamedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+struct IndexedPropertyHandlerConfiguration {
+  IndexedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      IndexedPropertyGetterCallback getter = 0,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyHandlerConfiguration(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter,
+      IndexedPropertyDescriptorCallback descriptor,
+      IndexedPropertyDeleterCallback deleter,
+      IndexedPropertyEnumeratorCallback enumerator,
+      IndexedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyGetterCallback getter;
+  IndexedPropertySetterCallback setter;
+  IndexedPropertyQueryCallback query;
+  IndexedPropertyDeleterCallback deleter;
+  IndexedPropertyEnumeratorCallback enumerator;
+  IndexedPropertyDefinerCallback definer;
+  IndexedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+/**
+ * An ObjectTemplate is used to create objects at runtime.
+ *
+ * Properties added to an ObjectTemplate are added to each object
+ * created from the ObjectTemplate.
+ */
+class V8_EXPORT ObjectTemplate : public Template {
+ public:
+  /** Creates an ObjectTemplate. */
+  static Local<ObjectTemplate> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> constructor = Local<FunctionTemplate>());
+  static V8_DEPRECATED("Use isolate version", Local<ObjectTemplate> New());
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<ObjectTemplate> FromSnapshot(Isolate* isolate,
+                                                 size_t index);
+
+  /** Creates a new instance of this template.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Object> NewInstance());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(Local<Context> context);
+
+  /**
+   * Sets an accessor on the object template.
+   *
+   * Whenever the property with the given name is accessed on objects
+   * created from this ObjectTemplate the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetAccessor(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+  void SetAccessor(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string is accessed on objects created
+   * from this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * SetNamedPropertyHandler() is different from SetHandler(), in
+   * that the latter can intercept symbol-named properties as well as
+   * string-named properties when called with a
+   * NamedPropertyHandlerConfiguration. New code should use SetHandler().
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if a property is present,
+   *   and if present, get its attributes.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the named
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetNamedPropertyHandler(NamedPropertyGetterCallback getter,
+                               NamedPropertySetterCallback setter = 0,
+                               NamedPropertyQueryCallback query = 0,
+                               NamedPropertyDeleterCallback deleter = 0,
+                               NamedPropertyEnumeratorCallback enumerator = 0,
+                               Local<Value> data = Local<Value>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string or a symbol is accessed on
+   * objects created from this object template, the provided callback is
+   * invoked instead of accessing the property directly on the JavaScript
+   * object.
+   *
+   * @param configuration The NamedPropertyHandlerConfiguration that defines the
+   * callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const NamedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if an object has a property.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the indexed
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetIndexedPropertyHandler(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>()) {
+    SetHandler(IndexedPropertyHandlerConfiguration(getter, setter, query,
+                                                   deleter, enumerator, data));
+  }
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * @param configuration The IndexedPropertyHandlerConfiguration that defines
+   * the callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const IndexedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets the callback to be used when calling instances created from
+   * this template as a function.  If no callback is set, instances
+   * behave like normal JavaScript objects that cannot be called as a
+   * function.
+   */
+  void SetCallAsFunctionHandler(FunctionCallback callback,
+                                Local<Value> data = Local<Value>());
+
+  /**
+   * Mark object instances of the template as undetectable.
+   *
+   * In many ways, undetectable objects behave as though they are not
+   * there.  They behave like 'undefined' in conditionals and when
+   * printed.  However, properties can be accessed and called as on
+   * normal objects.
+   */
+  void MarkAsUndetectable();
+
+  /**
+   * Sets access check callback on the object template and enables access
+   * checks.
+   *
+   * When accessing properties on instances of this object template,
+   * the access check callback will be called to determine whether or
+   * not to allow cross-context access to the properties.
+   */
+  void SetAccessCheckCallback(AccessCheckCallback callback,
+                              Local<Value> data = Local<Value>());
+
+  /**
+   * Like SetAccessCheckCallback but invokes an interceptor on failed access
+   * checks instead of looking up all-can-read properties. You can only use
+   * either this method or SetAccessCheckCallback, but not both at the same
+   * time.
+   */
+  void SetAccessCheckCallbackAndHandler(
+      AccessCheckCallback callback,
+      const NamedPropertyHandlerConfiguration& named_handler,
+      const IndexedPropertyHandlerConfiguration& indexed_handler,
+      Local<Value> data = Local<Value>());
+
+  /**
+   * Gets the number of internal fields for objects generated from
+   * this template.
+   */
+  int InternalFieldCount();
+
+  /**
+   * Sets the number of internal fields for objects generated from
+   * this template.
+   */
+  void SetInternalFieldCount(int value);
+
+  /**
+   * Returns true if the object will be an immutable prototype exotic object.
+   */
+  bool IsImmutableProto();
+
+  /**
+   * Makes the ObjectTempate for an immutable prototype exotic object, with an
+   * immutable __proto__.
+   */
+  void SetImmutableProto();
+
+ private:
+  ObjectTemplate();
+  static Local<ObjectTemplate> New(internal::Isolate* isolate,
+                                   Local<FunctionTemplate> constructor);
+  friend class FunctionTemplate;
+};
+
+/**
+ * A Signature specifies which receiver is valid for a function.
+ *
+ * A receiver matches a given signature if the receiver (or any of its
+ * hidden prototypes) was created from the signature's FunctionTemplate, or
+ * from a FunctionTemplate that inherits directly or indirectly from the
+ * signature's FunctionTemplate.
+ */
+class V8_EXPORT Signature : public Data {
+ public:
+  static Local<Signature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  Signature();
+};
+
+
+/**
+ * An AccessorSignature specifies which receivers are valid parameters
+ * to an accessor callback.
+ */
+class V8_EXPORT AccessorSignature : public Data {
+ public:
+  static Local<AccessorSignature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  AccessorSignature();
+};
+
+
+// --- Extensions ---
+
+class V8_EXPORT ExternalOneByteStringResourceImpl
+    : public String::ExternalOneByteStringResource {
+ public:
+  ExternalOneByteStringResourceImpl() : data_(0), length_(0) {}
+  ExternalOneByteStringResourceImpl(const char* data, size_t length)
+      : data_(data), length_(length) {}
+  const char* data() const { return data_; }
+  size_t length() const { return length_; }
+
+ private:
+  const char* data_;
+  size_t length_;
+};
+
+/**
+ * Ignore
+ */
+class V8_EXPORT Extension {  // NOLINT
+ public:
+  // Note that the strings passed into this constructor must live as long
+  // as the Extension itself.
+  Extension(const char* name,
+            const char* source = 0,
+            int dep_count = 0,
+            const char** deps = 0,
+            int source_length = -1);
+  virtual ~Extension() { }
+  virtual Local<FunctionTemplate> GetNativeFunctionTemplate(
+      Isolate* isolate, Local<String> name) {
+    return Local<FunctionTemplate>();
+  }
+
+  const char* name() const { return name_; }
+  size_t source_length() const { return source_length_; }
+  const String::ExternalOneByteStringResource* source() const {
+    return &source_; }
+  int dependency_count() { return dep_count_; }
+  const char** dependencies() { return deps_; }
+  void set_auto_enable(bool value) { auto_enable_ = value; }
+  bool auto_enable() { return auto_enable_; }
+
+  // Disallow copying and assigning.
+  Extension(const Extension&) = delete;
+  void operator=(const Extension&) = delete;
+
+ private:
+  const char* name_;
+  size_t source_length_;  // expected to initialize before source_
+  ExternalOneByteStringResourceImpl source_;
+  int dep_count_;
+  const char** deps_;
+  bool auto_enable_;
+};
+
+
+void V8_EXPORT RegisterExtension(Extension* extension);
+
+
+// --- Statics ---
+
+V8_INLINE Local<Primitive> Undefined(Isolate* isolate);
+V8_INLINE Local<Primitive> Null(Isolate* isolate);
+V8_INLINE Local<Boolean> True(Isolate* isolate);
+V8_INLINE Local<Boolean> False(Isolate* isolate);
+
+/**
+ * A set of constraints that specifies the limits of the runtime's memory use.
+ * You must set the heap size before initializing the VM - the size cannot be
+ * adjusted after the VM is initialized.
+ *
+ * If you are using threads then you should hold the V8::Locker lock while
+ * setting the stack limit and you must set a non-default stack limit separately
+ * for each thread.
+ *
+ * The arguments for set_max_semi_space_size, set_max_old_space_size,
+ * set_max_executable_size, set_code_range_size specify limits in MB.
+ */
+class V8_EXPORT ResourceConstraints {
+ public:
+  ResourceConstraints();
+
+  /**
+   * Configures the constraints with reasonable default values based on the
+   * capabilities of the current device the VM is running on.
+   *
+   * \param physical_memory The total amount of physical memory on the current
+   *   device, in bytes.
+   * \param virtual_memory_limit The amount of virtual memory on the current
+   *   device, in bytes, or zero, if there is no limit.
+   */
+  void ConfigureDefaults(uint64_t physical_memory,
+                         uint64_t virtual_memory_limit);
+
+  int max_semi_space_size() const { return max_semi_space_size_; }
+  void set_max_semi_space_size(int limit_in_mb) {
+    max_semi_space_size_ = limit_in_mb;
+  }
+  int max_old_space_size() const { return max_old_space_size_; }
+  void set_max_old_space_size(int limit_in_mb) {
+    max_old_space_size_ = limit_in_mb;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    int max_executable_size() const) {
+    return max_executable_size_;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    void set_max_executable_size(int limit_in_mb)) {
+    max_executable_size_ = limit_in_mb;
+  }
+  uint32_t* stack_limit() const { return stack_limit_; }
+  // Sets an address beyond which the VM's stack may not grow.
+  void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
+  size_t code_range_size() const { return code_range_size_; }
+  void set_code_range_size(size_t limit_in_mb) {
+    code_range_size_ = limit_in_mb;
+  }
+  size_t max_zone_pool_size() const { return max_zone_pool_size_; }
+  void set_max_zone_pool_size(const size_t bytes) {
+    max_zone_pool_size_ = bytes;
+  }
+
+ private:
+  int max_semi_space_size_;
+  int max_old_space_size_;
+  int max_executable_size_;
+  uint32_t* stack_limit_;
+  size_t code_range_size_;
+  size_t max_zone_pool_size_;
+};
+
+
+// --- Exceptions ---
+
+
+typedef void (*FatalErrorCallback)(const char* location, const char* message);
+
+typedef void (*OOMErrorCallback)(const char* location, bool is_heap_oom);
+
+typedef void (*MessageCallback)(Local<Message> message, Local<Value> data);
+
+// --- Tracing ---
+
+typedef void (*LogEventCallback)(const char* name, int event);
+
+/**
+ * Create new error objects by calling the corresponding error object
+ * constructor with the message.
+ */
+class V8_EXPORT Exception {
+ public:
+  static Local<Value> RangeError(Local<String> message);
+  static Local<Value> ReferenceError(Local<String> message);
+  static Local<Value> SyntaxError(Local<String> message);
+  static Local<Value> TypeError(Local<String> message);
+  static Local<Value> Error(Local<String> message);
+
+  /**
+   * Creates an error message for the given exception.
+   * Will try to reconstruct the original stack trace from the exception value,
+   * or capture the current stack trace if not available.
+   */
+  static Local<Message> CreateMessage(Isolate* isolate, Local<Value> exception);
+  V8_DEPRECATED("Use version with an Isolate*",
+                static Local<Message> CreateMessage(Local<Value> exception));
+
+  /**
+   * Returns the original stack trace that was captured at the creation time
+   * of a given exception, or an empty handle if not available.
+   */
+  static Local<StackTrace> GetStackTrace(Local<Value> exception);
+};
+
+
+// --- Counters Callbacks ---
+
+typedef int* (*CounterLookupCallback)(const char* name);
+
+typedef void* (*CreateHistogramCallback)(const char* name,
+                                         int min,
+                                         int max,
+                                         size_t buckets);
+
+typedef void (*AddHistogramSampleCallback)(void* histogram, int sample);
+
+// --- Memory Allocation Callback ---
+enum ObjectSpace {
+  kObjectSpaceNewSpace = 1 << 0,
+  kObjectSpaceOldSpace = 1 << 1,
+  kObjectSpaceCodeSpace = 1 << 2,
+  kObjectSpaceMapSpace = 1 << 3,
+  kObjectSpaceLoSpace = 1 << 4,
+  kObjectSpaceAll = kObjectSpaceNewSpace | kObjectSpaceOldSpace |
+                    kObjectSpaceCodeSpace | kObjectSpaceMapSpace |
+                    kObjectSpaceLoSpace
+};
+
+  enum AllocationAction {
+    kAllocationActionAllocate = 1 << 0,
+    kAllocationActionFree = 1 << 1,
+    kAllocationActionAll = kAllocationActionAllocate | kAllocationActionFree
+  };
+
+// --- Enter/Leave Script Callback ---
+typedef void (*BeforeCallEnteredCallback)(Isolate*);
+typedef void (*CallCompletedCallback)(Isolate*);
+typedef void (*DeprecatedCallCompletedCallback)();
+
+/**
+ * HostImportDynamicallyCallback is called when we require the
+ * embedder to load a module. This is used as part of the dynamic
+ * import syntax. The behavior of this callback is not specified in
+ * EcmaScript.
+ *
+ * The referrer is the name of the file which calls the dynamic
+ * import. The referrer can be used to resolve the module location.
+ *
+ * The specifier is the name of the module that should be imported.
+ *
+ * The DynamicImportResult object is used to signal success or failure
+ * by calling it's respective methods.
+ *
+ */
+typedef void (*HostImportModuleDynamicallyCallback)(
+    Isolate* isolate, Local<String> referrer, Local<String> specifier,
+    Local<DynamicImportResult> result);
+
+/**
+ * PromiseHook with type kInit is called when a new promise is
+ * created. When a new promise is created as part of the chain in the
+ * case of Promise.then or in the intermediate promises created by
+ * Promise.{race, all}/AsyncFunctionAwait, we pass the parent promise
+ * otherwise we pass undefined.
+ *
+ * PromiseHook with type kResolve is called at the beginning of
+ * resolve or reject function defined by CreateResolvingFunctions.
+ *
+ * PromiseHook with type kBefore is called at the beginning of the
+ * PromiseReactionJob.
+ *
+ * PromiseHook with type kAfter is called right at the end of the
+ * PromiseReactionJob.
+ */
+enum class PromiseHookType { kInit, kResolve, kBefore, kAfter };
+
+typedef void (*PromiseHook)(PromiseHookType type, Local<Promise> promise,
+                            Local<Value> parent);
+
+// --- Promise Reject Callback ---
+enum PromiseRejectEvent {
+  kPromiseRejectWithNoHandler = 0,
+  kPromiseHandlerAddedAfterReject = 1
+};
+
+class PromiseRejectMessage {
+ public:
+  PromiseRejectMessage(Local<Promise> promise, PromiseRejectEvent event,
+                       Local<Value> value, Local<StackTrace> stack_trace)
+      : promise_(promise),
+        event_(event),
+        value_(value),
+        stack_trace_(stack_trace) {}
+
+  V8_INLINE Local<Promise> GetPromise() const { return promise_; }
+  V8_INLINE PromiseRejectEvent GetEvent() const { return event_; }
+  V8_INLINE Local<Value> GetValue() const { return value_; }
+
+  V8_DEPRECATED("Use v8::Exception::CreateMessage(GetValue())->GetStackTrace()",
+                V8_INLINE Local<StackTrace> GetStackTrace() const) {
+    return stack_trace_;
+  }
+
+ private:
+  Local<Promise> promise_;
+  PromiseRejectEvent event_;
+  Local<Value> value_;
+  Local<StackTrace> stack_trace_;
+};
+
+typedef void (*PromiseRejectCallback)(PromiseRejectMessage message);
+
+// --- Microtasks Callbacks ---
+typedef void (*MicrotasksCompletedCallback)(Isolate*);
+typedef void (*MicrotaskCallback)(void* data);
+
+
+/**
+ * Policy for running microtasks:
+ *   - explicit: microtasks are invoked with Isolate::RunMicrotasks() method;
+ *   - scoped: microtasks invocation is controlled by MicrotasksScope objects;
+ *   - auto: microtasks are invoked when the script call depth decrements
+ *           to zero.
+ */
+enum class MicrotasksPolicy { kExplicit, kScoped, kAuto };
+
+
+/**
+ * This scope is used to control microtasks when kScopeMicrotasksInvocation
+ * is used on Isolate. In this mode every non-primitive call to V8 should be
+ * done inside some MicrotasksScope.
+ * Microtasks are executed when topmost MicrotasksScope marked as kRunMicrotasks
+ * exits.
+ * kDoNotRunMicrotasks should be used to annotate calls not intended to trigger
+ * microtasks.
+ */
+class V8_EXPORT MicrotasksScope {
+ public:
+  enum Type { kRunMicrotasks, kDoNotRunMicrotasks };
+
+  MicrotasksScope(Isolate* isolate, Type type);
+  ~MicrotasksScope();
+
+  /**
+   * Runs microtasks if no kRunMicrotasks scope is currently active.
+   */
+  static void PerformCheckpoint(Isolate* isolate);
+
+  /**
+   * Returns current depth of nested kRunMicrotasks scopes.
+   */
+  static int GetCurrentDepth(Isolate* isolate);
+
+  /**
+   * Returns true while microtasks are being executed.
+   */
+  static bool IsRunningMicrotasks(Isolate* isolate);
+
+  // Prevent copying.
+  MicrotasksScope(const MicrotasksScope&) = delete;
+  MicrotasksScope& operator=(const MicrotasksScope&) = delete;
+
+ private:
+  internal::Isolate* const isolate_;
+  bool run_;
+};
+
+
+// --- Failed Access Check Callback ---
+typedef void (*FailedAccessCheckCallback)(Local<Object> target,
+                                          AccessType type,
+                                          Local<Value> data);
+
+// --- AllowCodeGenerationFromStrings callbacks ---
+
+/**
+ * Callback to check if code generation from strings is allowed. See
+ * Context::AllowCodeGenerationFromStrings.
+ */
+typedef bool (*AllowCodeGenerationFromStringsCallback)(Local<Context> context);
+
+// --- WASM compilation callbacks ---
+typedef bool (*ExtensionCallback)(const FunctionCallbackInfo<Value>&);
+
+// --- Garbage Collection Callbacks ---
+
+/**
+ * Applications can register callback functions which will be called before and
+ * after certain garbage collection operations.  Allocations are not allowed in
+ * the callback functions, you therefore cannot manipulate objects (set or
+ * delete properties for example) since it is possible such operations will
+ * result in the allocation of objects.
+ */
+enum GCType {
+  kGCTypeScavenge = 1 << 0,
+  kGCTypeMarkSweepCompact = 1 << 1,
+  kGCTypeIncrementalMarking = 1 << 2,
+  kGCTypeProcessWeakCallbacks = 1 << 3,
+  kGCTypeAll = kGCTypeScavenge | kGCTypeMarkSweepCompact |
+               kGCTypeIncrementalMarking | kGCTypeProcessWeakCallbacks
+};
+
+/**
+ * GCCallbackFlags is used to notify additional information about the GC
+ * callback.
+ *   - kGCCallbackFlagConstructRetainedObjectInfos: The GC callback is for
+ *     constructing retained object infos.
+ *   - kGCCallbackFlagForced: The GC callback is for a forced GC for testing.
+ *   - kGCCallbackFlagSynchronousPhantomCallbackProcessing: The GC callback
+ *     is called synchronously without getting posted to an idle task.
+ *   - kGCCallbackFlagCollectAllAvailableGarbage: The GC callback is called
+ *     in a phase where V8 is trying to collect all available garbage
+ *     (e.g., handling a low memory notification).
+ *   - kGCCallbackScheduleIdleGarbageCollection: The GC callback is called to
+ *     trigger an idle garbage collection.
+ */
+enum GCCallbackFlags {
+  kNoGCCallbackFlags = 0,
+  kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1,
+  kGCCallbackFlagForced = 1 << 2,
+  kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3,
+  kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4,
+  kGCCallbackFlagCollectAllExternalMemory = 1 << 5,
+  kGCCallbackScheduleIdleGarbageCollection = 1 << 6,
+};
+
+typedef void (*GCCallback)(GCType type, GCCallbackFlags flags);
+
+typedef void (*InterruptCallback)(Isolate* isolate, void* data);
+
+
+/**
+ * Collection of V8 heap information.
+ *
+ * Instances of this class can be passed to v8::V8::HeapStatistics to
+ * get heap statistics from V8.
+ */
+class V8_EXPORT HeapStatistics {
+ public:
+  HeapStatistics();
+  size_t total_heap_size() { return total_heap_size_; }
+  size_t total_heap_size_executable() { return total_heap_size_executable_; }
+  size_t total_physical_size() { return total_physical_size_; }
+  size_t total_available_size() { return total_available_size_; }
+  size_t used_heap_size() { return used_heap_size_; }
+  size_t heap_size_limit() { return heap_size_limit_; }
+  size_t malloced_memory() { return malloced_memory_; }
+  size_t peak_malloced_memory() { return peak_malloced_memory_; }
+
+  /**
+   * Returns a 0/1 boolean, which signifies whether the V8 overwrite heap
+   * garbage with a bit pattern.
+   */
+  size_t does_zap_garbage() { return does_zap_garbage_; }
+
+ private:
+  size_t total_heap_size_;
+  size_t total_heap_size_executable_;
+  size_t total_physical_size_;
+  size_t total_available_size_;
+  size_t used_heap_size_;
+  size_t heap_size_limit_;
+  size_t malloced_memory_;
+  size_t peak_malloced_memory_;
+  bool does_zap_garbage_;
+
+  friend class V8;
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapSpaceStatistics {
+ public:
+  HeapSpaceStatistics();
+  const char* space_name() { return space_name_; }
+  size_t space_size() { return space_size_; }
+  size_t space_used_size() { return space_used_size_; }
+  size_t space_available_size() { return space_available_size_; }
+  size_t physical_space_size() { return physical_space_size_; }
+
+ private:
+  const char* space_name_;
+  size_t space_size_;
+  size_t space_used_size_;
+  size_t space_available_size_;
+  size_t physical_space_size_;
+
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapObjectStatistics {
+ public:
+  HeapObjectStatistics();
+  const char* object_type() { return object_type_; }
+  const char* object_sub_type() { return object_sub_type_; }
+  size_t object_count() { return object_count_; }
+  size_t object_size() { return object_size_; }
+
+ private:
+  const char* object_type_;
+  const char* object_sub_type_;
+  size_t object_count_;
+  size_t object_size_;
+
+  friend class Isolate;
+};
+
+class V8_EXPORT HeapCodeStatistics {
+ public:
+  HeapCodeStatistics();
+  size_t code_and_metadata_size() { return code_and_metadata_size_; }
+  size_t bytecode_and_metadata_size() { return bytecode_and_metadata_size_; }
+
+ private:
+  size_t code_and_metadata_size_;
+  size_t bytecode_and_metadata_size_;
+
+  friend class Isolate;
+};
+
+class RetainedObjectInfo;
+
+
+/**
+ * FunctionEntryHook is the type of the profile entry hook called at entry to
+ * any generated function when function-level profiling is enabled.
+ *
+ * \param function the address of the function that's being entered.
+ * \param return_addr_location points to a location on stack where the machine
+ *    return address resides. This can be used to identify the caller of
+ *    \p function, and/or modified to divert execution when \p function exits.
+ *
+ * \note the entry hook must not cause garbage collection.
+ */
+typedef void (*FunctionEntryHook)(uintptr_t function,
+                                  uintptr_t return_addr_location);
+
+/**
+ * A JIT code event is issued each time code is added, moved or removed.
+ *
+ * \note removal events are not currently issued.
+ */
+struct JitCodeEvent {
+  enum EventType {
+    CODE_ADDED,
+    CODE_MOVED,
+    CODE_REMOVED,
+    CODE_ADD_LINE_POS_INFO,
+    CODE_START_LINE_INFO_RECORDING,
+    CODE_END_LINE_INFO_RECORDING
+  };
+  // Definition of the code position type. The "POSITION" type means the place
+  // in the source code which are of interest when making stack traces to
+  // pin-point the source location of a stack frame as close as possible.
+  // The "STATEMENT_POSITION" means the place at the beginning of each
+  // statement, and is used to indicate possible break locations.
+  enum PositionType { POSITION, STATEMENT_POSITION };
+
+  // Type of event.
+  EventType type;
+  // Start of the instructions.
+  void* code_start;
+  // Size of the instructions.
+  size_t code_len;
+  // Script info for CODE_ADDED event.
+  Local<UnboundScript> script;
+  // User-defined data for *_LINE_INFO_* event. It's used to hold the source
+  // code line information which is returned from the
+  // CODE_START_LINE_INFO_RECORDING event. And it's passed to subsequent
+  // CODE_ADD_LINE_POS_INFO and CODE_END_LINE_INFO_RECORDING events.
+  void* user_data;
+
+  struct name_t {
+    // Name of the object associated with the code, note that the string is not
+    // zero-terminated.
+    const char* str;
+    // Number of chars in str.
+    size_t len;
+  };
+
+  struct line_info_t {
+    // PC offset
+    size_t offset;
+    // Code postion
+    size_t pos;
+    // The position type.
+    PositionType position_type;
+  };
+
+  union {
+    // Only valid for CODE_ADDED.
+    struct name_t name;
+
+    // Only valid for CODE_ADD_LINE_POS_INFO
+    struct line_info_t line_info;
+
+    // New location of instructions. Only valid for CODE_MOVED.
+    void* new_code_start;
+  };
+};
+
+/**
+ * Option flags passed to the SetRAILMode function.
+ * See documentation https://developers.google.com/web/tools/chrome-devtools/
+ * profile/evaluate-performance/rail
+ */
+enum RAILMode {
+  // Response performance mode: In this mode very low virtual machine latency
+  // is provided. V8 will try to avoid JavaScript execution interruptions.
+  // Throughput may be throttled.
+  PERFORMANCE_RESPONSE,
+  // Animation performance mode: In this mode low virtual machine latency is
+  // provided. V8 will try to avoid as many JavaScript execution interruptions
+  // as possible. Throughput may be throttled. This is the default mode.
+  PERFORMANCE_ANIMATION,
+  // Idle performance mode: The embedder is idle. V8 can complete deferred work
+  // in this mode.
+  PERFORMANCE_IDLE,
+  // Load performance mode: In this mode high throughput is provided. V8 may
+  // turn off latency optimizations.
+  PERFORMANCE_LOAD
+};
+
+/**
+ * Option flags passed to the SetJitCodeEventHandler function.
+ */
+enum JitCodeEventOptions {
+  kJitCodeEventDefault = 0,
+  // Generate callbacks for already existent code.
+  kJitCodeEventEnumExisting = 1
+};
+
+
+/**
+ * Callback function passed to SetJitCodeEventHandler.
+ *
+ * \param event code add, move or removal event.
+ */
+typedef void (*JitCodeEventHandler)(const JitCodeEvent* event);
+
+
+/**
+ * Interface for iterating through all external resources in the heap.
+ */
+class V8_EXPORT ExternalResourceVisitor {  // NOLINT
+ public:
+  virtual ~ExternalResourceVisitor() {}
+  virtual void VisitExternalString(Local<String> string) {}
+};
+
+
+/**
+ * Interface for iterating through all the persistent handles in the heap.
+ */
+class V8_EXPORT PersistentHandleVisitor {  // NOLINT
+ public:
+  virtual ~PersistentHandleVisitor() {}
+  virtual void VisitPersistentHandle(Persistent<Value>* value,
+                                     uint16_t class_id) {}
+};
+
+/**
+ * Memory pressure level for the MemoryPressureNotification.
+ * kNone hints V8 that there is no memory pressure.
+ * kModerate hints V8 to speed up incremental garbage collection at the cost of
+ * of higher latency due to garbage collection pauses.
+ * kCritical hints V8 to free memory as soon as possible. Garbage collection
+ * pauses at this level will be large.
+ */
+enum class MemoryPressureLevel { kNone, kModerate, kCritical };
+
+/**
+ * Interface for tracing through the embedder heap. During a v8 garbage
+ * collection, v8 collects hidden fields of all potential wrappers, and at the
+ * end of its marking phase iterates the collection and asks the embedder to
+ * trace through its heap and use reporter to report each JavaScript object
+ * reachable from any of the given wrappers.
+ *
+ * Before the first call to the TraceWrappersFrom function TracePrologue will be
+ * called. When the garbage collection cycle is finished, TraceEpilogue will be
+ * called.
+ */
+class V8_EXPORT EmbedderHeapTracer {
+ public:
+  enum ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION };
+
+  struct AdvanceTracingActions {
+    explicit AdvanceTracingActions(ForceCompletionAction force_completion_)
+        : force_completion(force_completion_) {}
+
+    ForceCompletionAction force_completion;
+  };
+
+  /**
+   * Called by v8 to register internal fields of found wrappers.
+   *
+   * The embedder is expected to store them somewhere and trace reachable
+   * wrappers from them when called through |AdvanceTracing|.
+   */
+  virtual void RegisterV8References(
+      const std::vector<std::pair<void*, void*> >& embedder_fields) = 0;
+
+  /**
+   * Called at the beginning of a GC cycle.
+   */
+  virtual void TracePrologue() = 0;
+
+  /**
+   * Called to to make a tracing step in the embedder.
+   *
+   * The embedder is expected to trace its heap starting from wrappers reported
+   * by RegisterV8References method, and report back all reachable wrappers.
+   * Furthermore, the embedder is expected to stop tracing by the given
+   * deadline.
+   *
+   * Returns true if there is still work to do.
+   */
+  virtual bool AdvanceTracing(double deadline_in_ms,
+                              AdvanceTracingActions actions) = 0;
+
+  /**
+   * Called at the end of a GC cycle.
+   *
+   * Note that allocation is *not* allowed within |TraceEpilogue|.
+   */
+  virtual void TraceEpilogue() = 0;
+
+  /**
+   * Called upon entering the final marking pause. No more incremental marking
+   * steps will follow this call.
+   */
+  virtual void EnterFinalPause() = 0;
+
+  /**
+   * Called when tracing is aborted.
+   *
+   * The embedder is expected to throw away all intermediate data and reset to
+   * the initial state.
+   */
+  virtual void AbortTracing() = 0;
+
+  /**
+   * Returns the number of wrappers that are still to be traced by the embedder.
+   */
+  virtual size_t NumberOfWrappersToTrace() { return 0; }
+
+ protected:
+  virtual ~EmbedderHeapTracer() = default;
+};
+
+/**
+ * Callback and supporting data used in SnapshotCreator to implement embedder
+ * logic to serialize internal fields.
+ */
+struct SerializeInternalFieldsCallback {
+  typedef StartupData (*CallbackFunction)(Local<Object> holder, int index,
+                                          void* data);
+  SerializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                  void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  CallbackFunction callback;
+  void* data;
+};
+// Note that these fields are called "internal fields" in the API and called
+// "embedder fields" within V8.
+typedef SerializeInternalFieldsCallback SerializeEmbedderFieldsCallback;
+
+/**
+ * Callback and supporting data used to implement embedder logic to deserialize
+ * internal fields.
+ */
+struct DeserializeInternalFieldsCallback {
+  typedef void (*CallbackFunction)(Local<Object> holder, int index,
+                                   StartupData payload, void* data);
+  DeserializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                    void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  void (*callback)(Local<Object> holder, int index, StartupData payload,
+                   void* data);
+  void* data;
+};
+typedef DeserializeInternalFieldsCallback DeserializeEmbedderFieldsCallback;
+
+/**
+ * Isolate represents an isolated instance of the V8 engine.  V8 isolates have
+ * completely separate states.  Objects from one isolate must not be used in
+ * other isolates.  The embedder can create multiple isolates and use them in
+ * parallel in multiple threads.  An isolate can be entered by at most one
+ * thread at any given time.  The Locker/Unlocker API must be used to
+ * synchronize.
+ */
+class V8_EXPORT Isolate {
+ public:
+  /**
+   * Initial configuration parameters for a new Isolate.
+   */
+  struct CreateParams {
+    CreateParams()
+        : entry_hook(nullptr),
+          code_event_handler(nullptr),
+          snapshot_blob(nullptr),
+          counter_lookup_callback(nullptr),
+          create_histogram_callback(nullptr),
+          add_histogram_sample_callback(nullptr),
+          array_buffer_allocator(nullptr),
+          external_references(nullptr),
+          allow_atomics_wait(true),
+          host_import_module_dynamically_callback_(nullptr) {}
+
+    /**
+     * The optional entry_hook allows the host application to provide the
+     * address of a function that's invoked on entry to every V8-generated
+     * function.  Note that entry_hook is invoked at the very start of each
+     * generated function.
+     * An entry_hook can only be provided in no-snapshot builds; in snapshot
+     * builds it must be nullptr.
+     */
+    FunctionEntryHook entry_hook;
+
+    /**
+     * Allows the host application to provide the address of a function that is
+     * notified each time code is added, moved or removed.
+     */
+    JitCodeEventHandler code_event_handler;
+
+    /**
+     * ResourceConstraints to use for the new Isolate.
+     */
+    ResourceConstraints constraints;
+
+    /**
+     * Explicitly specify a startup snapshot blob. The embedder owns the blob.
+     */
+    StartupData* snapshot_blob;
+
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * statistics counters.
+     */
+    CounterLookupCallback counter_lookup_callback;
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * histograms. The CreateHistogram function returns a
+     * histogram which will later be passed to the AddHistogramSample
+     * function.
+     */
+    CreateHistogramCallback create_histogram_callback;
+    AddHistogramSampleCallback add_histogram_sample_callback;
+
+    /**
+     * The ArrayBuffer::Allocator to use for allocating and freeing the backing
+     * store of ArrayBuffers.
+     */
+    ArrayBuffer::Allocator* array_buffer_allocator;
+
+    /**
+     * Specifies an optional nullptr-terminated array of raw addresses in the
+     * embedder that V8 can match against during serialization and use for
+     * deserialization. This array and its content must stay valid for the
+     * entire lifetime of the isolate.
+     */
+    intptr_t* external_references;
+
+    /**
+     * Whether calling Atomics.wait (a function that may block) is allowed in
+     * this isolate. This can also be configured via SetAllowAtomicsWait.
+     */
+    bool allow_atomics_wait;
+
+    /**
+     * This is an unfinished experimental feature, and is only exposed
+     * here for internal testing purposes. DO NOT USE.
+     *
+     * This specifies the callback called by the upcoming dynamic
+     * import() language feature to load modules.
+     */
+    HostImportModuleDynamicallyCallback
+        host_import_module_dynamically_callback_;
+  };
+
+
+  /**
+   * Stack-allocated class which sets the isolate for all operations
+   * executed within a local scope.
+   */
+  class V8_EXPORT Scope {
+   public:
+    explicit Scope(Isolate* isolate) : isolate_(isolate) {
+      isolate->Enter();
+    }
+
+    ~Scope() { isolate_->Exit(); }
+
+    // Prevent copying of Scope objects.
+    Scope(const Scope&) = delete;
+    Scope& operator=(const Scope&) = delete;
+
+   private:
+    Isolate* const isolate_;
+  };
+
+
+  /**
+   * Assert that no Javascript code is invoked.
+   */
+  class V8_EXPORT DisallowJavascriptExecutionScope {
+   public:
+    enum OnFailure { CRASH_ON_FAILURE, THROW_ON_FAILURE };
+
+    DisallowJavascriptExecutionScope(Isolate* isolate, OnFailure on_failure);
+    ~DisallowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    DisallowJavascriptExecutionScope(const DisallowJavascriptExecutionScope&) =
+        delete;
+    DisallowJavascriptExecutionScope& operator=(
+        const DisallowJavascriptExecutionScope&) = delete;
+
+   private:
+    bool on_failure_;
+    void* internal_;
+  };
+
+
+  /**
+   * Introduce exception to DisallowJavascriptExecutionScope.
+   */
+  class V8_EXPORT AllowJavascriptExecutionScope {
+   public:
+    explicit AllowJavascriptExecutionScope(Isolate* isolate);
+    ~AllowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    AllowJavascriptExecutionScope(const AllowJavascriptExecutionScope&) =
+        delete;
+    AllowJavascriptExecutionScope& operator=(
+        const AllowJavascriptExecutionScope&) = delete;
+
+   private:
+    void* internal_throws_;
+    void* internal_assert_;
+  };
+
+  /**
+   * Do not run microtasks while this scope is active, even if microtasks are
+   * automatically executed otherwise.
+   */
+  class V8_EXPORT SuppressMicrotaskExecutionScope {
+   public:
+    explicit SuppressMicrotaskExecutionScope(Isolate* isolate);
+    ~SuppressMicrotaskExecutionScope();
+
+    // Prevent copying of Scope objects.
+    SuppressMicrotaskExecutionScope(const SuppressMicrotaskExecutionScope&) =
+        delete;
+    SuppressMicrotaskExecutionScope& operator=(
+        const SuppressMicrotaskExecutionScope&) = delete;
+
+   private:
+    internal::Isolate* const isolate_;
+  };
+
+  /**
+   * Types of garbage collections that can be requested via
+   * RequestGarbageCollectionForTesting.
+   */
+  enum GarbageCollectionType {
+    kFullGarbageCollection,
+    kMinorGarbageCollection
+  };
+
+  /**
+   * Features reported via the SetUseCounterCallback callback. Do not change
+   * assigned numbers of existing items; add new features to the end of this
+   * list.
+   */
+  enum UseCounterFeature {
+    kUseAsm = 0,
+    kBreakIterator = 1,
+    kLegacyConst = 2,
+    kMarkDequeOverflow = 3,
+    kStoreBufferOverflow = 4,
+    kSlotsBufferOverflow = 5,
+    kObjectObserve = 6,
+    kForcedGC = 7,
+    kSloppyMode = 8,
+    kStrictMode = 9,
+    kStrongMode = 10,
+    kRegExpPrototypeStickyGetter = 11,
+    kRegExpPrototypeToString = 12,
+    kRegExpPrototypeUnicodeGetter = 13,
+    kIntlV8Parse = 14,
+    kIntlPattern = 15,
+    kIntlResolved = 16,
+    kPromiseChain = 17,
+    kPromiseAccept = 18,
+    kPromiseDefer = 19,
+    kHtmlCommentInExternalScript = 20,
+    kHtmlComment = 21,
+    kSloppyModeBlockScopedFunctionRedefinition = 22,
+    kForInInitializer = 23,
+    kArrayProtectorDirtied = 24,
+    kArraySpeciesModified = 25,
+    kArrayPrototypeConstructorModified = 26,
+    kArrayInstanceProtoModified = 27,
+    kArrayInstanceConstructorModified = 28,
+    kLegacyFunctionDeclaration = 29,
+    kRegExpPrototypeSourceGetter = 30,
+    kRegExpPrototypeOldFlagGetter = 31,
+    kDecimalWithLeadingZeroInStrictMode = 32,
+    kLegacyDateParser = 33,
+    kDefineGetterOrSetterWouldThrow = 34,
+    kFunctionConstructorReturnedUndefined = 35,
+    kAssigmentExpressionLHSIsCallInSloppy = 36,
+    kAssigmentExpressionLHSIsCallInStrict = 37,
+    kPromiseConstructorReturnedUndefined = 38,
+
+    // If you add new values here, you'll also need to update Chromium's:
+    // UseCounter.h, V8PerIsolateData.cpp, histograms.xml
+    kUseCounterFeatureCount  // This enum value must be last.
+  };
+
+  enum MessageErrorLevel {
+    kMessageLog = (1 << 0),
+    kMessageDebug = (1 << 1),
+    kMessageInfo = (1 << 2),
+    kMessageError = (1 << 3),
+    kMessageWarning = (1 << 4),
+    kMessageAll = kMessageLog | kMessageDebug | kMessageInfo | kMessageError |
+                  kMessageWarning,
+  };
+
+  typedef void (*UseCounterCallback)(Isolate* isolate,
+                                     UseCounterFeature feature);
+
+
+  /**
+   * Creates a new isolate.  Does not change the currently entered
+   * isolate.
+   *
+   * When an isolate is no longer used its resources should be freed
+   * by calling Dispose().  Using the delete operator is not allowed.
+   *
+   * V8::Initialize() must have run prior to this.
+   */
+  static Isolate* New(const CreateParams& params);
+
+  /**
+   * Returns the entered isolate for the current thread or NULL in
+   * case there is no current isolate.
+   *
+   * This method must not be invoked before V8::Initialize() was invoked.
+   */
+  static Isolate* GetCurrent();
+
+  /**
+   * Custom callback used by embedders to help V8 determine if it should abort
+   * when it throws and no internal handler is predicted to catch the
+   * exception. If --abort-on-uncaught-exception is used on the command line,
+   * then V8 will abort if either:
+   * - no custom callback is set.
+   * - the custom callback set returns true.
+   * Otherwise, the custom callback will not be called and V8 will not abort.
+   */
+  typedef bool (*AbortOnUncaughtExceptionCallback)(Isolate*);
+  void SetAbortOnUncaughtExceptionCallback(
+      AbortOnUncaughtExceptionCallback callback);
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to guide heuristics.
+   * It is allowed to call this function from another thread while
+   * the isolate is executing long running JavaScript code.
+   */
+  void MemoryPressureNotification(MemoryPressureLevel level);
+
+  /**
+   * Methods below this point require holding a lock (using Locker) in
+   * a multi-threaded environment.
+   */
+
+  /**
+   * Sets this isolate as the entered one for the current thread.
+   * Saves the previously entered one (if any), so that it can be
+   * restored when exiting.  Re-entering an isolate is allowed.
+   */
+  void Enter();
+
+  /**
+   * Exits this isolate by restoring the previously entered one in the
+   * current thread.  The isolate may still stay the same, if it was
+   * entered more than once.
+   *
+   * Requires: this == Isolate::GetCurrent().
+   */
+  void Exit();
+
+  /**
+   * Disposes the isolate.  The isolate must not be entered by any
+   * thread to be disposable.
+   */
+  void Dispose();
+
+  /**
+   * Dumps activated low-level V8 internal stats. This can be used instead
+   * of performing a full isolate disposal.
+   */
+  void DumpAndResetStats();
+
+  /**
+   * Discards all V8 thread-specific data for the Isolate. Should be used
+   * if a thread is terminating and it has used an Isolate that will outlive
+   * the thread -- all thread-specific data for an Isolate is discarded when
+   * an Isolate is disposed so this call is pointless if an Isolate is about
+   * to be Disposed.
+   */
+  void DiscardThreadSpecificMetadata();
+
+  /**
+   * Associate embedder-specific data with the isolate. |slot| has to be
+   * between 0 and GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE void SetData(uint32_t slot, void* data);
+
+  /**
+   * Retrieve embedder-specific data from the isolate.
+   * Returns NULL if SetData has never been called for the given |slot|.
+   */
+  V8_INLINE void* GetData(uint32_t slot);
+
+  /**
+   * Returns the maximum number of available embedder data slots. Valid slots
+   * are in the range of 0 - GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE static uint32_t GetNumberOfDataSlots();
+
+  /**
+   * Get statistics about the heap memory usage.
+   */
+  void GetHeapStatistics(HeapStatistics* heap_statistics);
+
+  /**
+   * Returns the number of spaces in the heap.
+   */
+  size_t NumberOfHeapSpaces();
+
+  /**
+   * Get the memory usage of a space in the heap.
+   *
+   * \param space_statistics The HeapSpaceStatistics object to fill in
+   *   statistics.
+   * \param index The index of the space to get statistics from, which ranges
+   *   from 0 to NumberOfHeapSpaces() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapSpaceStatistics(HeapSpaceStatistics* space_statistics,
+                              size_t index);
+
+  /**
+   * Returns the number of types of objects tracked in the heap at GC.
+   */
+  size_t NumberOfTrackedHeapObjectTypes();
+
+  /**
+   * Get statistics about objects in the heap.
+   *
+   * \param object_statistics The HeapObjectStatistics object to fill in
+   *   statistics of objects of given type, which were live in the previous GC.
+   * \param type_index The index of the type of object to fill details about,
+   *   which ranges from 0 to NumberOfTrackedHeapObjectTypes() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapObjectStatisticsAtLastGC(HeapObjectStatistics* object_statistics,
+                                       size_t type_index);
+
+  /**
+   * Get statistics about code and its metadata in the heap.
+   *
+   * \param object_statistics The HeapCodeStatistics object to fill in
+   *   statistics of code, bytecode and their metadata.
+   * \returns true on success.
+   */
+  bool GetHeapCodeAndMetadataStatistics(HeapCodeStatistics* object_statistics);
+
+  /**
+   * Get a call stack sample from the isolate.
+   * \param state Execution state.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \note GetStackSample should only be called when the JS thread is paused or
+   *       interrupted. Otherwise the behavior is undefined.
+   */
+  void GetStackSample(const RegisterState& state, void** frames,
+                      size_t frames_limit, SampleInfo* sample_info);
+
+  /**
+   * Adjusts the amount of registered external memory. Used to give V8 an
+   * indication of the amount of externally allocated memory that is kept alive
+   * by JavaScript objects. V8 uses this to decide when to perform global
+   * garbage collections. Registering externally allocated memory will trigger
+   * global garbage collections more often than it would otherwise in an attempt
+   * to garbage collect the JavaScript objects that keep the externally
+   * allocated memory alive.
+   *
+   * \param change_in_bytes the change in externally allocated memory that is
+   *   kept alive by JavaScript objects.
+   * \returns the adjusted value.
+   */
+  V8_INLINE int64_t
+      AdjustAmountOfExternalAllocatedMemory(int64_t change_in_bytes);
+
+  /**
+   * Returns the number of phantom handles without callbacks that were reset
+   * by the garbage collector since the last call to this function.
+   */
+  size_t NumberOfPhantomHandleResetsSinceLastCall();
+
+  /**
+   * Returns heap profiler for this isolate. Will return NULL until the isolate
+   * is initialized.
+   */
+  HeapProfiler* GetHeapProfiler();
+
+  /**
+   * Returns CPU profiler for this isolate. Will return NULL unless the isolate
+   * is initialized. It is the embedder's responsibility to stop all CPU
+   * profiling activities if it has started any.
+   */
+  V8_DEPRECATE_SOON("CpuProfiler should be created with CpuProfiler::New call.",
+                    CpuProfiler* GetCpuProfiler());
+
+  /** Returns true if this isolate has a current context. */
+  bool InContext();
+
+  /**
+   * Returns the context of the currently running JavaScript, or the context
+   * on the top of the stack if no JavaScript is running.
+   */
+  Local<Context> GetCurrentContext();
+
+  /**
+   * Returns the context of the calling JavaScript code.  That is the
+   * context of the top-most JavaScript frame.  If there are no
+   * JavaScript frames an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON(
+      "Calling context concept is not compatible with tail calls, and will be "
+      "removed.",
+      Local<Context> GetCallingContext());
+
+  /** Returns the last context entered through V8's C++ API. */
+  Local<Context> GetEnteredContext();
+
+  /**
+   * Returns either the last context entered through V8's C++ API, or the
+   * context of the currently running microtask while processing microtasks.
+   * If a context is entered while executing a microtask, that context is
+   * returned.
+   */
+  Local<Context> GetEnteredOrMicrotaskContext();
+
+  /**
+   * Schedules an exception to be thrown when returning to JavaScript.  When an
+   * exception has been scheduled it is illegal to invoke any JavaScript
+   * operation; the caller must return immediately and only after the exception
+   * has been handled does it become legal to invoke JavaScript operations.
+   */
+  Local<Value> ThrowException(Local<Value> exception);
+
+  typedef void (*GCCallback)(Isolate* isolate, GCType type,
+                             GCCallbackFlags flags);
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCPrologueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  void RemoveGCPrologueCallback(GCCallback callback);
+
+  /**
+   * Sets the embedder heap tracer for the isolate.
+   */
+  void SetEmbedderHeapTracer(EmbedderHeapTracer* tracer);
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCEpilogueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  void RemoveGCEpilogueCallback(GCCallback callback);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void TerminateExecution();
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   */
+  bool IsExecutionTerminating();
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void CancelTerminateExecution();
+
+  /**
+   * Request V8 to interrupt long running JavaScript code and invoke
+   * the given |callback| passing the given |data| to it. After |callback|
+   * returns control will be returned to the JavaScript code.
+   * There may be a number of interrupt requests in flight.
+   * Can be called from another thread without acquiring a |Locker|.
+   * Registered |callback| must not reenter interrupted Isolate.
+   */
+  void RequestInterrupt(InterruptCallback callback, void* data);
+
+  /**
+   * Request garbage collection in this Isolate. It is only valid to call this
+   * function if --expose_gc was specified.
+   *
+   * This should only be used for testing purposes and not to enforce a garbage
+   * collection schedule. It has strong negative impact on the garbage
+   * collection performance. Use IdleNotificationDeadline() or
+   * LowMemoryNotification() instead to influence the garbage collection
+   * schedule.
+   */
+  void RequestGarbageCollectionForTesting(GarbageCollectionType type);
+
+  /**
+   * Set the callback to invoke for logging event.
+   */
+  void SetEventLogger(LogEventCallback that);
+
+  /**
+   * Adds a callback to notify the host application right before a script
+   * is about to run. If a script re-enters the runtime during executing, the
+   * BeforeCallEnteredCallback is invoked for each re-entrance.
+   * Executing scripts inside the callback will re-trigger the callback.
+   */
+  void AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Removes callback that was installed by AddBeforeCallEnteredCallback.
+   */
+  void RemoveBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Adds a callback to notify the host application when a script finished
+   * running.  If a script re-enters the runtime during executing, the
+   * CallCompletedCallback is only invoked when the outer-most script
+   * execution ends.  Executing scripts inside the callback do not trigger
+   * further callbacks.
+   */
+  void AddCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void AddCallCompletedCallback(DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Removes callback that was installed by AddCallCompletedCallback.
+   */
+  void RemoveCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void RemoveCallCompletedCallback(
+          DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Experimental: Set the PromiseHook callback for various promise
+   * lifecycle events.
+   */
+  void SetPromiseHook(PromiseHook hook);
+
+  /**
+   * Set callback to notify about promise reject with no handler, or
+   * revocation of such a previous notification once the handler is added.
+   */
+  void SetPromiseRejectCallback(PromiseRejectCallback callback);
+
+  /**
+   * Experimental: Runs the Microtask Work Queue until empty
+   * Any exceptions thrown by microtask callbacks are swallowed.
+   */
+  void RunMicrotasks();
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(Local<Function> microtask);
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(MicrotaskCallback microtask, void* data = NULL);
+
+  /**
+   * Experimental: Controls how Microtasks are invoked. See MicrotasksPolicy
+   * for details.
+   */
+  void SetMicrotasksPolicy(MicrotasksPolicy policy);
+  V8_DEPRECATE_SOON("Use SetMicrotasksPolicy",
+                    void SetAutorunMicrotasks(bool autorun));
+
+  /**
+   * Experimental: Returns the policy controlling how Microtasks are invoked.
+   */
+  MicrotasksPolicy GetMicrotasksPolicy() const;
+  V8_DEPRECATE_SOON("Use GetMicrotasksPolicy",
+                    bool WillAutorunMicrotasks() const);
+
+  /**
+   * Experimental: adds a callback to notify the host application after
+   * microtasks were run. The callback is triggered by explicit RunMicrotasks
+   * call or automatic microtasks execution (see SetAutorunMicrotasks).
+   *
+   * Callback will trigger even if microtasks were attempted to run,
+   * but the microtasks queue was empty and no single microtask was actually
+   * executed.
+   *
+   * Executing scriptsinside the callback will not re-trigger microtasks and
+   * the callback.
+   */
+  void AddMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Removes callback that was installed by AddMicrotasksCompletedCallback.
+   */
+  void RemoveMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Sets a callback for counting the number of times a feature of V8 is used.
+   */
+  void SetUseCounterCallback(UseCounterCallback callback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * statistics counters.
+   */
+  void SetCounterFunction(CounterLookupCallback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * histograms. The CreateHistogram function returns a
+   * histogram which will later be passed to the AddHistogramSample
+   * function.
+   */
+  void SetCreateHistogramFunction(CreateHistogramCallback);
+  void SetAddHistogramSampleFunction(AddHistogramSampleCallback);
+
+  /**
+   * Optional notification that the embedder is idle.
+   * V8 uses the notification to perform garbage collection.
+   * This call can be used repeatedly if the embedder remains idle.
+   * Returns true if the embedder should stop calling IdleNotificationDeadline
+   * until real work has been done.  This indicates that V8 has done
+   * as much cleanup as it will be able to do.
+   *
+   * The deadline_in_seconds argument specifies the deadline V8 has to finish
+   * garbage collection work. deadline_in_seconds is compared with
+   * MonotonicallyIncreasingTime() and should be based on the same timebase as
+   * that function. There is no guarantee that the actual work will be done
+   * within the time limit.
+   */
+  bool IdleNotificationDeadline(double deadline_in_seconds);
+
+  V8_DEPRECATED("use IdleNotificationDeadline()",
+                bool IdleNotification(int idle_time_in_ms));
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to attempt to free memory.
+   */
+  void LowMemoryNotification();
+
+  /**
+   * Optional notification that a context has been disposed. V8 uses
+   * these notifications to guide the GC heuristic. Returns the number
+   * of context disposals - including this one - since the last time
+   * V8 had a chance to clean up.
+   *
+   * The optional parameter |dependant_context| specifies whether the disposed
+   * context was depending on state from other contexts or not.
+   */
+  int ContextDisposedNotification(bool dependant_context = true);
+
+  /**
+   * Optional notification that the isolate switched to the foreground.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInForegroundNotification();
+
+  /**
+   * Optional notification that the isolate switched to the background.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInBackgroundNotification();
+
+  /**
+   * Optional notification to tell V8 the current performance requirements
+   * of the embedder based on RAIL.
+   * V8 uses these notifications to guide heuristics.
+   * This is an unfinished experimental feature. Semantics and implementation
+   * may change frequently.
+   */
+  void SetRAILMode(RAILMode rail_mode);
+
+  /**
+   * Optional notification to tell V8 the current isolate is used for debugging
+   * and requires higher heap limit.
+   */
+  void IncreaseHeapLimitForDebugging();
+
+  /**
+   * Restores the original heap limit after IncreaseHeapLimitForDebugging().
+   */
+  void RestoreOriginalHeapLimit();
+
+  /**
+   * Returns true if the heap limit was increased for debugging and the
+   * original heap limit was not restored yet.
+   */
+  bool IsHeapLimitIncreasedForDebugging();
+
+  /**
+   * Allows the host application to provide the address of a function that is
+   * notified each time code is added, moved or removed.
+   *
+   * \param options options for the JIT code event handler.
+   * \param event_handler the JIT code event handler, which will be invoked
+   *     each time code is added, moved or removed.
+   * \note \p event_handler won't get notified of existent code.
+   * \note since code removal notifications are not currently issued, the
+   *     \p event_handler may get notifications of code that overlaps earlier
+   *     code notifications. This happens when code areas are reused, and the
+   *     earlier overlapping code areas should therefore be discarded.
+   * \note the events passed to \p event_handler and the strings they point to
+   *     are not guaranteed to live past each call. The \p event_handler must
+   *     copy strings and other parameters it needs to keep around.
+   * \note the set of events declared in JitCodeEvent::EventType is expected to
+   *     grow over time, and the JitCodeEvent structure is expected to accrue
+   *     new members. The \p event_handler function must ignore event codes
+   *     it does not recognize to maintain future compatibility.
+   * \note Use Isolate::CreateParams to get events for code executed during
+   *     Isolate setup.
+   */
+  void SetJitCodeEventHandler(JitCodeEventOptions options,
+                              JitCodeEventHandler event_handler);
+
+  /**
+   * Modifies the stack limit for this Isolate.
+   *
+   * \param stack_limit An address beyond which the Vm's stack may not grow.
+   *
+   * \note  If you are using threads then you should hold the V8::Locker lock
+   *     while setting the stack limit and you must set a non-default stack
+   *     limit separately for each thread.
+   */
+  void SetStackLimit(uintptr_t stack_limit);
+
+  /**
+   * Returns a memory range that can potentially contain jitted code.
+   *
+   * On Win64, embedders are advised to install function table callbacks for
+   * these ranges, as default SEH won't be able to unwind through jitted code.
+   *
+   * The first page of the code range is reserved for the embedder and is
+   * committed, writable, and executable.
+   *
+   * Might be empty on other platforms.
+   *
+   * https://code.google.com/p/v8/issues/detail?id=3598
+   */
+  void GetCodeRange(void** start, size_t* length_in_bytes);
+
+  /** Set the callback to invoke in case of fatal errors. */
+  void SetFatalErrorHandler(FatalErrorCallback that);
+
+  /** Set the callback to invoke in case of OOM errors. */
+  void SetOOMErrorHandler(OOMErrorCallback that);
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  void SetAllowCodeGenerationFromStringsCallback(
+      AllowCodeGenerationFromStringsCallback callback);
+
+  /**
+   * Embedder over{ride|load} injection points for wasm APIs.
+   */
+  void SetWasmModuleCallback(ExtensionCallback callback);
+  void SetWasmCompileCallback(ExtensionCallback callback);
+  void SetWasmInstanceCallback(ExtensionCallback callback);
+  void SetWasmInstantiateCallback(ExtensionCallback callback);
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  bool IsDead();
+
+  /**
+   * Adds a message listener (errors only).
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  bool AddMessageListener(MessageCallback that,
+                          Local<Value> data = Local<Value>());
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   *
+   * A listener can listen for particular error levels by providing a mask.
+   */
+  bool AddMessageListenerWithErrorLevel(MessageCallback that,
+                                        int message_levels,
+                                        Local<Value> data = Local<Value>());
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  void RemoveMessageListeners(MessageCallback that);
+
+  /** Callback function for reporting failed access checks.*/
+  void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback);
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  void SetCaptureStackTraceForUncaughtExceptions(
+      bool capture, int frame_limit = 10,
+      StackTrace::StackTraceOptions options = StackTrace::kOverview);
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  void VisitExternalResources(ExternalResourceVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  void VisitHandlesForPartialDependence(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are weak to be marked as inactive if there is no
+   * pending activity for the handle.
+   */
+  void VisitWeakHandles(PersistentHandleVisitor* visitor);
+
+  /**
+   * Check if this isolate is in use.
+   * True if at least one thread Enter'ed this isolate.
+   */
+  bool IsInUse();
+
+  /**
+   * Set whether calling Atomics.wait (a function that may block) is allowed in
+   * this isolate. This can also be configured via
+   * CreateParams::allow_atomics_wait.
+   */
+  void SetAllowAtomicsWait(bool allow);
+
+  Isolate() = delete;
+  ~Isolate() = delete;
+  Isolate(const Isolate&) = delete;
+  Isolate& operator=(const Isolate&) = delete;
+  void* operator new(size_t size) = delete;
+  void operator delete(void*, size_t) = delete;
+
+ private:
+  template <class K, class V, class Traits>
+  friend class PersistentValueMapBase;
+
+  void ReportExternalAllocationLimitReached();
+};
+
+class V8_EXPORT StartupData {
+ public:
+  const char* data;
+  int raw_size;
+};
+
+
+/**
+ * EntropySource is used as a callback function when v8 needs a source
+ * of entropy.
+ */
+typedef bool (*EntropySource)(unsigned char* buffer, size_t length);
+
+/**
+ * ReturnAddressLocationResolver is used as a callback function when v8 is
+ * resolving the location of a return address on the stack. Profilers that
+ * change the return address on the stack can use this to resolve the stack
+ * location to whereever the profiler stashed the original return address.
+ *
+ * \param return_addr_location A location on stack where a machine
+ *    return address resides.
+ * \returns Either return_addr_location, or else a pointer to the profiler's
+ *    copy of the original return address.
+ *
+ * \note The resolver function must not cause garbage collection.
+ */
+typedef uintptr_t (*ReturnAddressLocationResolver)(
+    uintptr_t return_addr_location);
+
+
+/**
+ * Container class for static utility functions.
+ */
+class V8_EXPORT V8 {
+ public:
+  /** Set the callback to invoke in case of fatal errors. */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFatalErrorHandler(FatalErrorCallback that));
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void SetAllowCodeGenerationFromStringsCallback(
+                                 AllowCodeGenerationFromStringsCallback that));
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  V8_INLINE static V8_DEPRECATED("Use isolate version", bool IsDead());
+
+  /**
+   * Hand startup data to V8, in case the embedder has chosen to build
+   * V8 with external startup data.
+   *
+   * Note:
+   * - By default the startup data is linked into the V8 library, in which
+   *   case this function is not meaningful.
+   * - If this needs to be called, it needs to be called before V8
+   *   tries to make use of its built-ins.
+   * - To avoid unnecessary copies of data, V8 will point directly into the
+   *   given data blob, so pretty please keep it around until V8 exit.
+   * - Compression of the startup blob might be useful, but needs to
+   *   handled entirely on the embedders' side.
+   * - The call will abort if the data is invalid.
+   */
+  static void SetNativesDataBlob(StartupData* startup_blob);
+  static void SetSnapshotDataBlob(StartupData* startup_blob);
+
+  /**
+   * Bootstrap an isolate and a context from scratch to create a startup
+   * snapshot. Include the side-effects of running the optional script.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   */
+  static StartupData CreateSnapshotDataBlob(const char* embedded_source = NULL);
+
+  /**
+   * Bootstrap an isolate and a context from the cold startup blob, run the
+   * warm-up script to trigger code compilation. The side effects are then
+   * discarded. The resulting startup snapshot will include compiled code.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   * The argument startup blob is untouched.
+   */
+  static StartupData WarmUpSnapshotDataBlob(StartupData cold_startup_blob,
+                                            const char* warmup_source);
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool AddMessageListener(MessageCallback that,
+                              Local<Value> data = Local<Value>()));
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void RemoveMessageListeners(MessageCallback that));
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetCaptureStackTraceForUncaughtExceptions(
+          bool capture, int frame_limit = 10,
+          StackTrace::StackTraceOptions options = StackTrace::kOverview));
+
+  /**
+   * Sets V8 flags from a string.
+   */
+  static void SetFlagsFromString(const char* str, int length);
+
+  /**
+   * Sets V8 flags from the command line.
+   */
+  static void SetFlagsFromCommandLine(int* argc,
+                                      char** argv,
+                                      bool remove_flags);
+
+  /** Get the version string. */
+  static const char* GetVersion();
+
+  /** Callback function for reporting failed access checks.*/
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback));
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCPrologueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCPrologueCallback(GCCallback callback));
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCEpilogueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCEpilogueCallback(GCCallback callback));
+
+  /**
+   * Initializes V8. This function needs to be called before the first Isolate
+   * is created. It always returns true.
+   */
+  static bool Initialize();
+
+  /**
+   * Allows the host application to provide a callback which can be used
+   * as a source of entropy for random number generators.
+   */
+  static void SetEntropySource(EntropySource source);
+
+  /**
+   * Allows the host application to provide a callback that allows v8 to
+   * cooperate with a profiler that rewrites return addresses on stack.
+   */
+  static void SetReturnAddressLocationResolver(
+      ReturnAddressLocationResolver return_address_resolver);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to terminate the current JS execution.
+   */
+  V8_INLINE static V8_DEPRECATED("Use isolate version",
+                                 void TerminateExecution(Isolate* isolate));
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   *
+   * \param isolate The isolate in which to check.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool IsExecutionTerminating(Isolate* isolate = NULL));
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to resume execution capability.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void CancelTerminateExecution(Isolate* isolate));
+
+  /**
+   * Releases any resources used by v8 and stops any utility threads
+   * that may be running.  Note that disposing v8 is permanent, it
+   * cannot be reinitialized.
+   *
+   * It should generally not be necessary to dispose v8 before exiting
+   * a process, this should happen automatically.  It is only necessary
+   * to use if the process needs the resources taken up by v8.
+   */
+  static bool Dispose();
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitExternalResources(ExternalResourceVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in isolate's heap that have
+   * class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(Isolate* isolate,
+                                    PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesForPartialDependence(Isolate* isolate,
+                                            PersistentHandleVisitor* visitor));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. Returns true on success.
+   *
+   * If V8 was compiled with the ICU data in an external file, the location
+   * of the data file has to be provided.
+   */
+  V8_DEPRECATE_SOON(
+      "Use version with default location.",
+      static bool InitializeICU(const char* icu_data_file = nullptr));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. If V8 was compiled with
+   * the ICU data in an external file and when the default location of that
+   * file should be used, a path to the executable must be provided.
+   * Returns true on success.
+   *
+   * The default is a file called icudtl.dat side-by-side with the executable.
+   *
+   * Optionally, the location of the data file can be provided to override the
+   * default.
+   */
+  static bool InitializeICUDefaultLocation(const char* exec_path,
+                                           const char* icu_data_file = nullptr);
+
+  /**
+   * Initialize the external startup data. The embedder only needs to
+   * invoke this method when external startup data was enabled in a build.
+   *
+   * If V8 was compiled with the startup data in an external file, then
+   * V8 needs to be given those external files during startup. There are
+   * three ways to do this:
+   * - InitializeExternalStartupData(const char*)
+   *   This will look in the given directory for files "natives_blob.bin"
+   *   and "snapshot_blob.bin" - which is what the default build calls them.
+   * - InitializeExternalStartupData(const char*, const char*)
+   *   As above, but will directly use the two given file names.
+   * - Call SetNativesDataBlob, SetNativesDataBlob.
+   *   This will read the blobs from the given data structures and will
+   *   not perform any file IO.
+   */
+  static void InitializeExternalStartupData(const char* directory_path);
+  static void InitializeExternalStartupData(const char* natives_blob,
+                                            const char* snapshot_blob);
+  /**
+   * Sets the v8::Platform to use. This should be invoked before V8 is
+   * initialized.
+   */
+  static void InitializePlatform(Platform* platform);
+
+  /**
+   * Clears all references to the v8::Platform. This should be invoked after
+   * V8 was disposed.
+   */
+  static void ShutdownPlatform();
+
+#if V8_OS_LINUX && V8_TARGET_ARCH_X64 && !V8_OS_ANDROID
+  /**
+   * Give the V8 signal handler a chance to handle a fault.
+   *
+   * This function determines whether a memory access violation can be recovered
+   * by V8. If so, it will return true and modify context to return to a code
+   * fragment that can recover from the fault. Otherwise, TryHandleSignal will
+   * return false.
+   *
+   * The parameters to this function correspond to those passed to a Linux
+   * signal handler.
+   *
+   * \param signal_number The signal number.
+   *
+   * \param info A pointer to the siginfo_t structure provided to the signal
+   * handler.
+   *
+   * \param context The third argument passed to the Linux signal handler, which
+   * points to a ucontext_t structure.
+   */
+  static bool TryHandleSignal(int signal_number, void* info, void* context);
+#endif  // V8_OS_LINUX
+
+  /**
+   * Enable the default signal handler rather than using one provided by the
+   * embedder.
+   */
+  static bool RegisterDefaultSignalHandler();
+
+ private:
+  V8();
+
+  static internal::Object** GlobalizeReference(internal::Isolate* isolate,
+                                               internal::Object** handle);
+  static internal::Object** CopyPersistent(internal::Object** handle);
+  static void DisposeGlobal(internal::Object** global_handle);
+  static void MakeWeak(internal::Object** location, void* data,
+                       WeakCallbackInfo<void>::Callback weak_callback,
+                       WeakCallbackType type);
+  static void MakeWeak(internal::Object** location, void* data,
+                       // Must be 0 or -1.
+                       int internal_field_index1,
+                       // Must be 1 or -1.
+                       int internal_field_index2,
+                       WeakCallbackInfo<void>::Callback weak_callback);
+  static void MakeWeak(internal::Object*** location_addr);
+  static void* ClearWeak(internal::Object** location);
+  static Value* Eternalize(Isolate* isolate, Value* handle);
+
+  static void RegisterExternallyReferencedObject(internal::Object** object,
+                                                 internal::Isolate* isolate);
+
+  template <class K, class V, class T>
+  friend class PersistentValueMapBase;
+
+  static void FromJustIsNothing();
+  static void ToLocalEmpty();
+  static void InternalFieldOutOfBounds(int index);
+  template <class T> friend class Local;
+  template <class T>
+  friend class MaybeLocal;
+  template <class T>
+  friend class Maybe;
+  template <class T>
+  friend class WeakCallbackInfo;
+  template <class T> friend class Eternal;
+  template <class T> friend class PersistentBase;
+  template <class T, class M> friend class Persistent;
+  friend class Context;
+};
+
+/**
+ * Helper class to create a snapshot data blob.
+ */
+class V8_EXPORT SnapshotCreator {
+ public:
+  enum class FunctionCodeHandling { kClear, kKeep };
+
+  /**
+   * Create and enter an isolate, and set it up for serialization.
+   * The isolate is either created from scratch or from an existing snapshot.
+   * The caller keeps ownership of the argument snapshot.
+   * \param existing_blob existing snapshot from which to create this one.
+   * \param external_references a null-terminated array of external references
+   *        that must be equivalent to CreateParams::external_references.
+   */
+  SnapshotCreator(intptr_t* external_references = nullptr,
+                  StartupData* existing_blob = nullptr);
+
+  ~SnapshotCreator();
+
+  /**
+   * \returns the isolate prepared by the snapshot creator.
+   */
+  Isolate* GetIsolate();
+
+  /**
+   * Set the default context to be included in the snapshot blob.
+   * The snapshot will not contain the global proxy, and we expect one or a
+   * global object template to create one, to be provided upon deserialization.
+   */
+  void SetDefaultContext(Local<Context> context);
+
+  /**
+   * Add additional context to be included in the snapshot blob.
+   * The snapshot will include the global proxy.
+   *
+   * \param callback optional callback to serialize internal fields.
+   *
+   * \returns the index of the context in the snapshot blob.
+   */
+  size_t AddContext(Local<Context> context,
+                    SerializeInternalFieldsCallback callback =
+                        SerializeInternalFieldsCallback());
+
+  /**
+   * Add a template to be included in the snapshot blob.
+   * \returns the index of the template in the snapshot blob.
+   */
+  size_t AddTemplate(Local<Template> template_obj);
+
+  /**
+   * Created a snapshot data blob.
+   * This must not be called from within a handle scope.
+   * \param function_code_handling whether to include compiled function code
+   *        in the snapshot.
+   * \returns { nullptr, 0 } on failure, and a startup snapshot on success. The
+   *        caller acquires ownership of the data array in the return value.
+   */
+  StartupData CreateBlob(FunctionCodeHandling function_code_handling);
+
+  // Disallow copying and assigning.
+  SnapshotCreator(const SnapshotCreator&) = delete;
+  void operator=(const SnapshotCreator&) = delete;
+
+ private:
+  void* data_;
+};
+
+/**
+ * A simple Maybe type, representing an object which may or may not have a
+ * value, see https://hackage.haskell.org/package/base/docs/Data-Maybe.html.
+ *
+ * If an API method returns a Maybe<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, a
+ * "Nothing" value is returned.
+ */
+template <class T>
+class Maybe {
+ public:
+  V8_INLINE bool IsNothing() const { return !has_value_; }
+  V8_INLINE bool IsJust() const { return has_value_; }
+
+  /**
+   * An alias for |FromJust|. Will crash if the Maybe<> is nothing.
+   */
+  V8_INLINE T ToChecked() const { return FromJust(); }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), |false| is returned and |out| is left untouched.
+   */
+  V8_WARN_UNUSED_RESULT V8_INLINE bool To(T* out) const {
+    if (V8_LIKELY(IsJust())) *out = value_;
+    return IsJust();
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), V8 will crash the process.
+   */
+  V8_INLINE T FromJust() const {
+    if (V8_UNLIKELY(!IsJust())) V8::FromJustIsNothing();
+    return value_;
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T, using a default value if this
+   * Maybe<> is nothing (empty).
+   */
+  V8_INLINE T FromMaybe(const T& default_value) const {
+    return has_value_ ? value_ : default_value;
+  }
+
+  V8_INLINE bool operator==(const Maybe& other) const {
+    return (IsJust() == other.IsJust()) &&
+           (!IsJust() || FromJust() == other.FromJust());
+  }
+
+  V8_INLINE bool operator!=(const Maybe& other) const {
+    return !operator==(other);
+  }
+
+ private:
+  Maybe() : has_value_(false) {}
+  explicit Maybe(const T& t) : has_value_(true), value_(t) {}
+
+  bool has_value_;
+  T value_;
+
+  template <class U>
+  friend Maybe<U> Nothing();
+  template <class U>
+  friend Maybe<U> Just(const U& u);
+};
+
+
+template <class T>
+inline Maybe<T> Nothing() {
+  return Maybe<T>();
+}
+
+
+template <class T>
+inline Maybe<T> Just(const T& t) {
+  return Maybe<T>(t);
+}
+
+
+/**
+ * An external exception handler.
+ */
+class V8_EXPORT TryCatch {
+ public:
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  V8_DEPRECATED("Use isolate version", TryCatch());
+
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  TryCatch(Isolate* isolate);
+
+  /**
+   * Unregisters and deletes this try/catch block.
+   */
+  ~TryCatch();
+
+  /**
+   * Returns true if an exception has been caught by this try/catch block.
+   */
+  bool HasCaught() const;
+
+  /**
+   * For certain types of exceptions, it makes no sense to continue execution.
+   *
+   * If CanContinue returns false, the correct action is to perform any C++
+   * cleanup needed and then return.  If CanContinue returns false and
+   * HasTerminated returns true, it is possible to call
+   * CancelTerminateExecution in order to continue calling into the engine.
+   */
+  bool CanContinue() const;
+
+  /**
+   * Returns true if an exception has been caught due to script execution
+   * being terminated.
+   *
+   * There is no JavaScript representation of an execution termination
+   * exception.  Such exceptions are thrown when the TerminateExecution
+   * methods are called to terminate a long-running script.
+   *
+   * If such an exception has been thrown, HasTerminated will return true,
+   * indicating that it is possible to call CancelTerminateExecution in order
+   * to continue calling into the engine.
+   */
+  bool HasTerminated() const;
+
+  /**
+   * Throws the exception caught by this TryCatch in a way that avoids
+   * it being caught again by this same TryCatch.  As with ThrowException
+   * it is illegal to execute any JavaScript operations after calling
+   * ReThrow; the caller must return immediately to where the exception
+   * is caught.
+   */
+  Local<Value> ReThrow();
+
+  /**
+   * Returns the exception caught by this try/catch block.  If no exception has
+   * been caught an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been destroyed.
+   */
+  Local<Value> Exception() const;
+
+  /**
+   * Returns the .stack property of the thrown object.  If no .stack
+   * property is present an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON("Use maybe version.", Local<Value> StackTrace() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> StackTrace(
+      Local<Context> context) const;
+
+  /**
+   * Returns the message associated with this exception.  If there is
+   * no message associated an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been
+   * destroyed.
+   */
+  Local<v8::Message> Message() const;
+
+  /**
+   * Clears any exceptions that may have been caught by this try/catch block.
+   * After this method has been called, HasCaught() will return false. Cancels
+   * the scheduled exception if it is caught and ReThrow() is not called before.
+   *
+   * It is not necessary to clear a try/catch block before using it again; if
+   * another exception is thrown the previously caught exception will just be
+   * overwritten.  However, it is often a good idea since it makes it easier
+   * to determine which operation threw a given exception.
+   */
+  void Reset();
+
+  /**
+   * Set verbosity of the external exception handler.
+   *
+   * By default, exceptions that are caught by an external exception
+   * handler are not reported.  Call SetVerbose with true on an
+   * external exception handler to have exceptions caught by the
+   * handler reported as if they were not caught.
+   */
+  void SetVerbose(bool value);
+
+  /**
+   * Returns true if verbosity is enabled.
+   */
+  bool IsVerbose() const;
+
+  /**
+   * Set whether or not this TryCatch should capture a Message object
+   * which holds source information about where the exception
+   * occurred.  True by default.
+   */
+  void SetCaptureMessage(bool value);
+
+  /**
+   * There are cases when the raw address of C++ TryCatch object cannot be
+   * used for comparisons with addresses into the JS stack. The cases are:
+   * 1) ARM, ARM64 and MIPS simulators which have separate JS stack.
+   * 2) Address sanitizer allocates local C++ object in the heap when
+   *    UseAfterReturn mode is enabled.
+   * This method returns address that can be used for comparisons with
+   * addresses into the JS stack. When neither simulator nor ASAN's
+   * UseAfterReturn is enabled, then the address returned will be the address
+   * of the C++ try catch handler itself.
+   */
+  static void* JSStackComparableAddress(TryCatch* handler) {
+    if (handler == NULL) return NULL;
+    return handler->js_stack_comparable_address_;
+  }
+
+  TryCatch(const TryCatch&) = delete;
+  void operator=(const TryCatch&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  void ResetInternal();
+
+  internal::Isolate* isolate_;
+  TryCatch* next_;
+  void* exception_;
+  void* message_obj_;
+  void* js_stack_comparable_address_;
+  bool is_verbose_ : 1;
+  bool can_continue_ : 1;
+  bool capture_message_ : 1;
+  bool rethrow_ : 1;
+  bool has_terminated_ : 1;
+
+  friend class internal::Isolate;
+};
+
+
+// --- Context ---
+
+
+/**
+ * A container for extension names.
+ */
+class V8_EXPORT ExtensionConfiguration {
+ public:
+  ExtensionConfiguration() : name_count_(0), names_(NULL) { }
+  ExtensionConfiguration(int name_count, const char* names[])
+      : name_count_(name_count), names_(names) { }
+
+  const char** begin() const { return &names_[0]; }
+  const char** end()  const { return &names_[name_count_]; }
+
+ private:
+  const int name_count_;
+  const char** names_;
+};
+
+/**
+ * A sandboxed execution context with its own set of built-in objects
+ * and functions.
+ */
+class V8_EXPORT Context {
+ public:
+  /**
+   * Returns the global proxy object.
+   *
+   * Global proxy object is a thin wrapper whose prototype points to actual
+   * context's global object with the properties like Object, etc. This is done
+   * that way for security reasons (for more details see
+   * https://wiki.mozilla.org/Gecko:SplitWindow).
+   *
+   * Please note that changes to global proxy object prototype most probably
+   * would break VM---v8 expects only global object as a prototype of global
+   * proxy object.
+   */
+  Local<Object> Global();
+
+  /**
+   * Detaches the global object from its context before
+   * the global object can be reused to create a new context.
+   */
+  void DetachGlobal();
+
+  /**
+   * Creates a new context and returns a handle to the newly allocated
+   * context.
+   *
+   * \param isolate The isolate in which to create the context.
+   *
+   * \param extensions An optional extension configuration containing
+   * the extensions to be installed in the newly created context.
+   *
+   * \param global_template An optional object template from which the
+   * global object for the newly created context will be created.
+   *
+   * \param global_object An optional global object to be reused for
+   * the newly created context. This global object must have been
+   * created by a previous call to Context::New with the same global
+   * template. The state of the global object will be completely reset
+   * and only object identify will remain.
+   */
+  static Local<Context> New(
+      Isolate* isolate, ExtensionConfiguration* extensions = NULL,
+      MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Create a new context from a (non-default) context snapshot. There
+   * is no way to provide a global object template since we do not create
+   * a new global object from template, but we can reuse a global object.
+   *
+   * \param isolate See v8::Context::New.
+   *
+   * \param context_snapshot_index The index of the context snapshot to
+   * deserialize from. Use v8::Context::New for the default snapshot.
+   *
+   * \param embedder_fields_deserializer Optional callback to deserialize
+   * internal fields. It should match the SerializeInternalFieldCallback used
+   * to serialize.
+   *
+   * \param extensions See v8::Context::New.
+   *
+   * \param global_object See v8::Context::New.
+   */
+
+  static MaybeLocal<Context> FromSnapshot(
+      Isolate* isolate, size_t context_snapshot_index,
+      DeserializeInternalFieldsCallback embedder_fields_deserializer =
+          DeserializeInternalFieldsCallback(),
+      ExtensionConfiguration* extensions = nullptr,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Returns an global object that isn't backed by an actual context.
+   *
+   * The global template needs to have access checks with handlers installed.
+   * If an existing global object is passed in, the global object is detached
+   * from its context.
+   *
+   * Note that this is different from a detached context where all accesses to
+   * the global proxy will fail. Instead, the access check handlers are invoked.
+   *
+   * It is also not possible to detach an object returned by this method.
+   * Instead, the access check handlers need to return nothing to achieve the
+   * same effect.
+   *
+   * It is possible, however, to create a new context from the global object
+   * returned by this method.
+   */
+  static MaybeLocal<Object> NewRemoteContext(
+      Isolate* isolate, Local<ObjectTemplate> global_template,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Sets the security token for the context.  To access an object in
+   * another context, the security tokens must match.
+   */
+  void SetSecurityToken(Local<Value> token);
+
+  /** Restores the security token to the default value. */
+  void UseDefaultSecurityToken();
+
+  /** Returns the security token of this context.*/
+  Local<Value> GetSecurityToken();
+
+  /**
+   * Enter this context.  After entering a context, all code compiled
+   * and run is compiled and run in this context.  If another context
+   * is already entered, this old context is saved so it can be
+   * restored when the new context is exited.
+   */
+  void Enter();
+
+  /**
+   * Exit this context.  Exiting the current context restores the
+   * context that was in place when entering the current context.
+   */
+  void Exit();
+
+  /** Returns an isolate associated with a current context. */
+  Isolate* GetIsolate();
+
+  /**
+   * The field at kDebugIdIndex used to be reserved for the inspector.
+   * It now serves no purpose.
+   */
+  enum EmbedderDataFields { kDebugIdIndex = 0 };
+
+  /**
+   * Gets the embedder data with the given index, which must have been set by a
+   * previous call to SetEmbedderData with the same index.
+   */
+  V8_INLINE Local<Value> GetEmbedderData(int index);
+
+  /**
+   * Gets the binding object used by V8 extras. Extra natives get a reference
+   * to this object and can use it to "export" functionality by adding
+   * properties. Extra natives can also "import" functionality by accessing
+   * properties added by the embedder using the V8 API.
+   */
+  Local<Object> GetExtrasBindingObject();
+
+  /**
+   * Sets the embedder data with the given index, growing the data as
+   * needed. Note that index 0 currently has a special meaning for Chrome's
+   * debugger.
+   */
+  void SetEmbedderData(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from the embedder data with the given
+   * index, which must have been set by a previous call to
+   * SetAlignedPointerInEmbedderData with the same index. Note that index 0
+   * currently has a special meaning for Chrome's debugger.
+   */
+  V8_INLINE void* GetAlignedPointerFromEmbedderData(int index);
+
+  /**
+   * Sets a 2-byte-aligned native pointer in the embedder data with the given
+   * index, growing the data as needed. Note that index 0 currently has a
+   * special meaning for Chrome's debugger.
+   */
+  void SetAlignedPointerInEmbedderData(int index, void* value);
+
+  /**
+   * Control whether code generation from strings is allowed. Calling
+   * this method with false will disable 'eval' and the 'Function'
+   * constructor for code running in this context. If 'eval' or the
+   * 'Function' constructor are used an exception will be thrown.
+   *
+   * If code generation from strings is not allowed the
+   * V8::AllowCodeGenerationFromStrings callback will be invoked if
+   * set before blocking the call to 'eval' or the 'Function'
+   * constructor. If that callback returns true, the call will be
+   * allowed, otherwise an exception will be thrown. If no callback is
+   * set an exception will be thrown.
+   */
+  void AllowCodeGenerationFromStrings(bool allow);
+
+  /**
+   * Returns true if code generation from strings is allowed for the context.
+   * For more details see AllowCodeGenerationFromStrings(bool) documentation.
+   */
+  bool IsCodeGenerationFromStringsAllowed();
+
+  /**
+   * Sets the error description for the exception that is thrown when
+   * code generation from strings is not allowed and 'eval' or the 'Function'
+   * constructor are called.
+   */
+  void SetErrorMessageForCodeGenerationFromStrings(Local<String> message);
+
+  /**
+   * Estimate the memory in bytes retained by this context.
+   */
+  V8_DEPRECATED("no longer supported", size_t EstimatedSize());
+
+  /**
+   * Stack-allocated class which sets the execution context for all
+   * operations executed within a local scope.
+   */
+  class Scope {
+   public:
+    explicit V8_INLINE Scope(Local<Context> context) : context_(context) {
+      context_->Enter();
+    }
+    V8_INLINE ~Scope() { context_->Exit(); }
+
+   private:
+    Local<Context> context_;
+  };
+
+ private:
+  friend class Value;
+  friend class Script;
+  friend class Object;
+  friend class Function;
+
+  Local<Value> SlowGetEmbedderData(int index);
+  void* SlowGetAlignedPointerFromEmbedderData(int index);
+};
+
+
+/**
+ * Multiple threads in V8 are allowed, but only one thread at a time is allowed
+ * to use any given V8 isolate, see the comments in the Isolate class. The
+ * definition of 'using a V8 isolate' includes accessing handles or holding onto
+ * object pointers obtained from V8 handles while in the particular V8 isolate.
+ * It is up to the user of V8 to ensure, perhaps with locking, that this
+ * constraint is not violated. In addition to any other synchronization
+ * mechanism that may be used, the v8::Locker and v8::Unlocker classes must be
+ * used to signal thread switches to V8.
+ *
+ * v8::Locker is a scoped lock object. While it's active, i.e. between its
+ * construction and destruction, the current thread is allowed to use the locked
+ * isolate. V8 guarantees that an isolate can be locked by at most one thread at
+ * any time. In other words, the scope of a v8::Locker is a critical section.
+ *
+ * Sample usage:
+* \code
+ * ...
+ * {
+ *   v8::Locker locker(isolate);
+ *   v8::Isolate::Scope isolate_scope(isolate);
+ *   ...
+ *   // Code using V8 and isolate goes here.
+ *   ...
+ * } // Destructor called here
+ * \endcode
+ *
+ * If you wish to stop using V8 in a thread A you can do this either by
+ * destroying the v8::Locker object as above or by constructing a v8::Unlocker
+ * object:
+ *
+ * \code
+ * {
+ *   isolate->Exit();
+ *   v8::Unlocker unlocker(isolate);
+ *   ...
+ *   // Code not using V8 goes here while V8 can run in another thread.
+ *   ...
+ * } // Destructor called here.
+ * isolate->Enter();
+ * \endcode
+ *
+ * The Unlocker object is intended for use in a long-running callback from V8,
+ * where you want to release the V8 lock for other threads to use.
+ *
+ * The v8::Locker is a recursive lock, i.e. you can lock more than once in a
+ * given thread. This can be useful if you have code that can be called either
+ * from code that holds the lock or from code that does not. The Unlocker is
+ * not recursive so you can not have several Unlockers on the stack at once, and
+ * you can not use an Unlocker in a thread that is not inside a Locker's scope.
+ *
+ * An unlocker will unlock several lockers if it has to and reinstate the
+ * correct depth of locking on its destruction, e.g.:
+ *
+ * \code
+ * // V8 not locked.
+ * {
+ *   v8::Locker locker(isolate);
+ *   Isolate::Scope isolate_scope(isolate);
+ *   // V8 locked.
+ *   {
+ *     v8::Locker another_locker(isolate);
+ *     // V8 still locked (2 levels).
+ *     {
+ *       isolate->Exit();
+ *       v8::Unlocker unlocker(isolate);
+ *       // V8 not locked.
+ *     }
+ *     isolate->Enter();
+ *     // V8 locked again (2 levels).
+ *   }
+ *   // V8 still locked (1 level).
+ * }
+ * // V8 Now no longer locked.
+ * \endcode
+ */
+class V8_EXPORT Unlocker {
+ public:
+  /**
+   * Initialize Unlocker for a given Isolate.
+   */
+  V8_INLINE explicit Unlocker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Unlocker();
+ private:
+  void Initialize(Isolate* isolate);
+
+  internal::Isolate* isolate_;
+};
+
+
+class V8_EXPORT Locker {
+ public:
+  /**
+   * Initialize Locker for a given Isolate.
+   */
+  V8_INLINE explicit Locker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Locker();
+
+  /**
+   * Returns whether or not the locker for a given isolate, is locked by the
+   * current thread.
+   */
+  static bool IsLocked(Isolate* isolate);
+
+  /**
+   * Returns whether v8::Locker is being used by this V8 instance.
+   */
+  static bool IsActive();
+
+  // Disallow copying and assigning.
+  Locker(const Locker&) = delete;
+  void operator=(const Locker&) = delete;
+
+ private:
+  void Initialize(Isolate* isolate);
+
+  bool has_lock_;
+  bool top_level_;
+  internal::Isolate* isolate_;
+};
+
+
+// --- Implementation ---
+
+
+namespace internal {
+
+const int kApiPointerSize = sizeof(void*);  // NOLINT
+const int kApiIntSize = sizeof(int);  // NOLINT
+const int kApiInt64Size = sizeof(int64_t);  // NOLINT
+
+// Tag information for HeapObject.
+const int kHeapObjectTag = 1;
+const int kHeapObjectTagSize = 2;
+const intptr_t kHeapObjectTagMask = (1 << kHeapObjectTagSize) - 1;
+
+// Tag information for Smi.
+const int kSmiTag = 0;
+const int kSmiTagSize = 1;
+const intptr_t kSmiTagMask = (1 << kSmiTagSize) - 1;
+
+template <size_t ptr_size> struct SmiTagging;
+
+template<int kSmiShiftSize>
+V8_INLINE internal::Object* IntToSmi(int value) {
+  int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
+  uintptr_t tagged_value =
+      (static_cast<uintptr_t>(value) << smi_shift_bits) | kSmiTag;
+  return reinterpret_cast<internal::Object*>(tagged_value);
+}
+
+// Smi constants for 32-bit systems.
+template <> struct SmiTagging<4> {
+  enum { kSmiShiftSize = 0, kSmiValueSize = 31 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Throw away top 32 bits and shift down (requires >> to be sign extending).
+    return static_cast<int>(reinterpret_cast<intptr_t>(value)) >> shift_bits;
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as an tagged small integer, the two
+    // most-significant bits of 'value' must be either 00 or 11 due to
+    // sign-extension. To check this we add 01 to the two
+    // most-significant bits, and check if the most-significant bit is 0
+    //
+    // CAUTION: The original code below:
+    // bool result = ((value + 0x40000000) & 0x80000000) == 0;
+    // may lead to incorrect results according to the C language spec, and
+    // in fact doesn't work correctly with gcc4.1.1 in some cases: The
+    // compiler may produce undefined results in case of signed integer
+    // overflow. The computation must be done w/ unsigned ints.
+    return static_cast<uintptr_t>(value + 0x40000000U) < 0x80000000U;
+  }
+};
+
+// Smi constants for 64-bit systems.
+template <> struct SmiTagging<8> {
+  enum { kSmiShiftSize = 31, kSmiValueSize = 32 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Shift down and throw away top 32 bits.
+    return static_cast<int>(reinterpret_cast<intptr_t>(value) >> shift_bits);
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as a long smi, the value must be a 32-bit integer.
+    return (value == static_cast<int32_t>(value));
+  }
+};
+
+typedef SmiTagging<kApiPointerSize> PlatformSmiTagging;
+const int kSmiShiftSize = PlatformSmiTagging::kSmiShiftSize;
+const int kSmiValueSize = PlatformSmiTagging::kSmiValueSize;
+V8_INLINE static bool SmiValuesAre31Bits() { return kSmiValueSize == 31; }
+V8_INLINE static bool SmiValuesAre32Bits() { return kSmiValueSize == 32; }
+
+/**
+ * This class exports constants and functionality from within v8 that
+ * is necessary to implement inline functions in the v8 api.  Don't
+ * depend on functions and constants defined here.
+ */
+class Internals {
+ public:
+  // These values match non-compiler-dependent values defined within
+  // the implementation of v8.
+  static const int kHeapObjectMapOffset = 0;
+  static const int kMapInstanceTypeAndBitFieldOffset =
+      1 * kApiPointerSize + kApiIntSize;
+  static const int kStringResourceOffset = 3 * kApiPointerSize;
+
+  static const int kOddballKindOffset = 4 * kApiPointerSize + sizeof(double);
+  static const int kForeignAddressOffset = kApiPointerSize;
+  static const int kJSObjectHeaderSize = 3 * kApiPointerSize;
+  static const int kFixedArrayHeaderSize = 2 * kApiPointerSize;
+  static const int kContextHeaderSize = 2 * kApiPointerSize;
+  static const int kContextEmbedderDataIndex = 5;
+  static const int kFullStringRepresentationMask = 0x0f;
+  static const int kStringEncodingMask = 0x8;
+  static const int kExternalTwoByteRepresentationTag = 0x02;
+  static const int kExternalOneByteRepresentationTag = 0x0a;
+
+  static const int kIsolateEmbedderDataOffset = 0 * kApiPointerSize;
+  static const int kExternalMemoryOffset = 4 * kApiPointerSize;
+  static const int kExternalMemoryLimitOffset =
+      kExternalMemoryOffset + kApiInt64Size;
+  static const int kIsolateRootsOffset = kExternalMemoryLimitOffset +
+                                         kApiInt64Size + kApiInt64Size +
+                                         kApiPointerSize + kApiPointerSize;
+  static const int kUndefinedValueRootIndex = 4;
+  static const int kTheHoleValueRootIndex = 5;
+  static const int kNullValueRootIndex = 6;
+  static const int kTrueValueRootIndex = 7;
+  static const int kFalseValueRootIndex = 8;
+  static const int kEmptyStringRootIndex = 9;
+
+  static const int kNodeClassIdOffset = 1 * kApiPointerSize;
+  static const int kNodeFlagsOffset = 1 * kApiPointerSize + 3;
+  static const int kNodeStateMask = 0x7;
+  static const int kNodeStateIsWeakValue = 2;
+  static const int kNodeStateIsPendingValue = 3;
+  static const int kNodeStateIsNearDeathValue = 4;
+  static const int kNodeIsIndependentShift = 3;
+  static const int kNodeIsActiveShift = 4;
+
+  static const int kJSApiObjectType = 0xbb;
+  static const int kJSObjectType = 0xbc;
+  static const int kFirstNonstringType = 0x80;
+  static const int kOddballType = 0x82;
+  static const int kForeignType = 0x86;
+
+  static const int kUndefinedOddballKind = 5;
+  static const int kNullOddballKind = 3;
+
+  static const uint32_t kNumIsolateDataSlots = 4;
+
+  V8_EXPORT static void CheckInitializedImpl(v8::Isolate* isolate);
+  V8_INLINE static void CheckInitialized(v8::Isolate* isolate) {
+#ifdef V8_ENABLE_CHECKS
+    CheckInitializedImpl(isolate);
+#endif
+  }
+
+  V8_INLINE static bool HasHeapObjectTag(const internal::Object* value) {
+    return ((reinterpret_cast<intptr_t>(value) & kHeapObjectTagMask) ==
+            kHeapObjectTag);
+  }
+
+  V8_INLINE static int SmiValue(const internal::Object* value) {
+    return PlatformSmiTagging::SmiToInt(value);
+  }
+
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return PlatformSmiTagging::IntToSmi(value);
+  }
+
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    return PlatformSmiTagging::IsValidSmi(value);
+  }
+
+  V8_INLINE static int GetInstanceType(const internal::Object* obj) {
+    typedef internal::Object O;
+    O* map = ReadField<O*>(obj, kHeapObjectMapOffset);
+    // Map::InstanceType is defined so that it will always be loaded into
+    // the LS 8 bits of one 16-bit word, regardless of endianess.
+    return ReadField<uint16_t>(map, kMapInstanceTypeAndBitFieldOffset) & 0xff;
+  }
+
+  V8_INLINE static int GetOddballKind(const internal::Object* obj) {
+    typedef internal::Object O;
+    return SmiValue(ReadField<O*>(obj, kOddballKindOffset));
+  }
+
+  V8_INLINE static bool IsExternalTwoByteString(int instance_type) {
+    int representation = (instance_type & kFullStringRepresentationMask);
+    return representation == kExternalTwoByteRepresentationTag;
+  }
+
+  V8_INLINE static uint8_t GetNodeFlag(internal::Object** obj, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      return *addr & static_cast<uint8_t>(1U << shift);
+  }
+
+  V8_INLINE static void UpdateNodeFlag(internal::Object** obj,
+                                       bool value, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      uint8_t mask = static_cast<uint8_t>(1U << shift);
+      *addr = static_cast<uint8_t>((*addr & ~mask) | (value << shift));
+  }
+
+  V8_INLINE static uint8_t GetNodeState(internal::Object** obj) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    return *addr & kNodeStateMask;
+  }
+
+  V8_INLINE static void UpdateNodeState(internal::Object** obj,
+                                        uint8_t value) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    *addr = static_cast<uint8_t>((*addr & ~kNodeStateMask) | value);
+  }
+
+  V8_INLINE static void SetEmbedderData(v8::Isolate* isolate,
+                                        uint32_t slot,
+                                        void* data) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) +
+                    kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    *reinterpret_cast<void**>(addr) = data;
+  }
+
+  V8_INLINE static void* GetEmbedderData(const v8::Isolate* isolate,
+                                         uint32_t slot) {
+    const uint8_t* addr = reinterpret_cast<const uint8_t*>(isolate) +
+        kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    return *reinterpret_cast<void* const*>(addr);
+  }
+
+  V8_INLINE static internal::Object** GetRoot(v8::Isolate* isolate,
+                                              int index) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) + kIsolateRootsOffset;
+    return reinterpret_cast<internal::Object**>(addr + index * kApiPointerSize);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadField(const internal::Object* ptr, int offset) {
+    const uint8_t* addr =
+        reinterpret_cast<const uint8_t*>(ptr) + offset - kHeapObjectTag;
+    return *reinterpret_cast<const T*>(addr);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadEmbedderData(const v8::Context* context, int index) {
+    typedef internal::Object O;
+    typedef internal::Internals I;
+    O* ctx = *reinterpret_cast<O* const*>(context);
+    int embedder_data_offset = I::kContextHeaderSize +
+        (internal::kApiPointerSize * I::kContextEmbedderDataIndex);
+    O* embedder_data = I::ReadField<O*>(ctx, embedder_data_offset);
+    int value_offset =
+        I::kFixedArrayHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<T>(embedder_data, value_offset);
+  }
+};
+
+}  // namespace internal
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, Local<T> that) {
+  return New(isolate, that.val_);
+}
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, const PersistentBase<T>& that) {
+  return New(isolate, that.val_);
+}
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return Local<T>();
+  T* that_ptr = that;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that_ptr);
+  return Local<T>(reinterpret_cast<T*>(HandleScope::CreateHandle(
+      reinterpret_cast<internal::Isolate*>(isolate), *p)));
+}
+
+
+template<class T>
+template<class S>
+void Eternal<T>::Set(Isolate* isolate, Local<S> handle) {
+  TYPE_CHECK(T, S);
+  val_ = reinterpret_cast<T*>(
+      V8::Eternalize(isolate, reinterpret_cast<Value*>(*handle)));
+}
+
+template <class T>
+Local<T> Eternal<T>::Get(Isolate* isolate) const {
+  // The eternal handle will never go away, so as with the roots, we don't even
+  // need to open a handle.
+  return Local<T>(val_);
+}
+
+
+template <class T>
+Local<T> MaybeLocal<T>::ToLocalChecked() {
+  if (V8_UNLIKELY(val_ == nullptr)) V8::ToLocalEmpty();
+  return Local<T>(val_);
+}
+
+
+template <class T>
+void* WeakCallbackInfo<T>::GetInternalField(int index) const {
+#ifdef V8_ENABLE_CHECKS
+  if (index < 0 || index >= kEmbedderFieldsInWeakCallback) {
+    V8::InternalFieldOutOfBounds(index);
+  }
+#endif
+  return embedder_fields_[index];
+}
+
+
+template <class T>
+T* PersistentBase<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return NULL;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that);
+  return reinterpret_cast<T*>(
+      V8::GlobalizeReference(reinterpret_cast<internal::Isolate*>(isolate),
+                             p));
+}
+
+
+template <class T, class M>
+template <class S, class M2>
+void Persistent<T, M>::Copy(const Persistent<S, M2>& that) {
+  TYPE_CHECK(T, S);
+  this->Reset();
+  if (that.IsEmpty()) return;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that.val_);
+  this->val_ = reinterpret_cast<T*>(V8::CopyPersistent(p));
+  M::Copy(that, this);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsIndependent() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                        I::kNodeIsIndependentShift);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsNearDeath() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  uint8_t node_state =
+      I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_));
+  return node_state == I::kNodeStateIsNearDeathValue ||
+      node_state == I::kNodeStateIsPendingValue;
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsWeak() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_)) ==
+      I::kNodeStateIsWeakValue;
+}
+
+
+template <class T>
+void PersistentBase<T>::Reset() {
+  if (this->IsEmpty()) return;
+  V8::DisposeGlobal(reinterpret_cast<internal::Object**>(this->val_));
+  val_ = 0;
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate, const Local<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate,
+                              const PersistentBase<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <typename P>
+V8_INLINE void PersistentBase<T>::SetWeak(
+    P* parameter, typename WeakCallbackInfo<P>::Callback callback,
+    WeakCallbackType type) {
+  typedef typename WeakCallbackInfo<void>::Callback Callback;
+  V8::MakeWeak(reinterpret_cast<internal::Object**>(this->val_), parameter,
+               reinterpret_cast<Callback>(callback), type);
+}
+
+template <class T>
+void PersistentBase<T>::SetWeak() {
+  V8::MakeWeak(reinterpret_cast<internal::Object***>(&this->val_));
+}
+
+template <class T>
+template <typename P>
+P* PersistentBase<T>::ClearWeak() {
+  return reinterpret_cast<P*>(
+    V8::ClearWeak(reinterpret_cast<internal::Object**>(this->val_)));
+}
+
+template <class T>
+void PersistentBase<T>::RegisterExternalReference(Isolate* isolate) const {
+  if (IsEmpty()) return;
+  V8::RegisterExternallyReferencedObject(
+      reinterpret_cast<internal::Object**>(this->val_),
+      reinterpret_cast<internal::Isolate*>(isolate));
+}
+
+template <class T>
+void PersistentBase<T>::MarkIndependent() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                    true,
+                    I::kNodeIsIndependentShift);
+}
+
+template <class T>
+void PersistentBase<T>::MarkActive() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_), true,
+                    I::kNodeIsActiveShift);
+}
+
+
+template <class T>
+void PersistentBase<T>::SetWrapperClassId(uint16_t class_id) {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  *reinterpret_cast<uint16_t*>(addr) = class_id;
+}
+
+
+template <class T>
+uint16_t PersistentBase<T>::WrapperClassId() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return 0;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  return *reinterpret_cast<uint16_t*>(addr);
+}
+
+
+template<typename T>
+ReturnValue<T>::ReturnValue(internal::Object** slot) : value_(slot) {}
+
+template<typename T>
+template<typename S>
+void ReturnValue<T>::Set(const Persistent<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Global<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Local<S> handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template<typename T>
+void ReturnValue<T>::Set(double i) {
+  TYPE_CHECK(T, Number);
+  Set(Number::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(int32_t i) {
+  TYPE_CHECK(T, Integer);
+  typedef internal::Internals I;
+  if (V8_LIKELY(I::IsValidSmi(i))) {
+    *value_ = I::IntToSmi(i);
+    return;
+  }
+  Set(Integer::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(uint32_t i) {
+  TYPE_CHECK(T, Integer);
+  // Can't simply use INT32_MAX here for whatever reason.
+  bool fits_into_int32_t = (i & (1U << 31)) == 0;
+  if (V8_LIKELY(fits_into_int32_t)) {
+    Set(static_cast<int32_t>(i));
+    return;
+  }
+  Set(Integer::NewFromUnsigned(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(bool value) {
+  TYPE_CHECK(T, Boolean);
+  typedef internal::Internals I;
+  int root_index;
+  if (value) {
+    root_index = I::kTrueValueRootIndex;
+  } else {
+    root_index = I::kFalseValueRootIndex;
+  }
+  *value_ = *I::GetRoot(GetIsolate(), root_index);
+}
+
+template<typename T>
+void ReturnValue<T>::SetNull() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kNullValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetUndefined() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kUndefinedValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetEmptyString() {
+  TYPE_CHECK(T, String);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kEmptyStringRootIndex);
+}
+
+template <typename T>
+Isolate* ReturnValue<T>::GetIsolate() const {
+  // Isolate is always the pointer below the default value on the stack.
+  return *reinterpret_cast<Isolate**>(&value_[-2]);
+}
+
+template <typename T>
+Local<Value> ReturnValue<T>::Get() const {
+  typedef internal::Internals I;
+  if (*value_ == *I::GetRoot(GetIsolate(), I::kTheHoleValueRootIndex))
+    return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>::New(GetIsolate(), reinterpret_cast<Value*>(value_));
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(S* whatever) {
+  // Uncompilable to prevent inadvertent misuse.
+  TYPE_CHECK(S*, Primitive);
+}
+
+template<typename T>
+internal::Object* ReturnValue<T>::GetDefaultValue() {
+  // Default value is always the pointer below value_ on the stack.
+  return value_[-1];
+}
+
+template <typename T>
+FunctionCallbackInfo<T>::FunctionCallbackInfo(internal::Object** implicit_args,
+                                              internal::Object** values,
+                                              int length)
+    : implicit_args_(implicit_args), values_(values), length_(length) {}
+
+template<typename T>
+Local<Value> FunctionCallbackInfo<T>::operator[](int i) const {
+  if (i < 0 || length_ <= i) return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>(reinterpret_cast<Value*>(values_ - i));
+}
+
+
+template<typename T>
+Local<Function> FunctionCallbackInfo<T>::Callee() const {
+  return Local<Function>(reinterpret_cast<Function*>(
+      &implicit_args_[kCalleeIndex]));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(
+      &implicit_args_[kHolderIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::NewTarget() const {
+  return Local<Value>(
+      reinterpret_cast<Value*>(&implicit_args_[kNewTargetIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&implicit_args_[kDataIndex]));
+}
+
+
+template<typename T>
+Isolate* FunctionCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&implicit_args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+ReturnValue<T> FunctionCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&implicit_args_[kReturnValueIndex]);
+}
+
+
+template<typename T>
+bool FunctionCallbackInfo<T>::IsConstructCall() const {
+  return !NewTarget()->IsUndefined();
+}
+
+
+template<typename T>
+int FunctionCallbackInfo<T>::Length() const {
+  return length_;
+}
+
+ScriptOrigin::ScriptOrigin(Local<Value> resource_name,
+                           Local<Integer> resource_line_offset,
+                           Local<Integer> resource_column_offset,
+                           Local<Boolean> resource_is_shared_cross_origin,
+                           Local<Integer> script_id,
+                           Local<Value> source_map_url,
+                           Local<Boolean> resource_is_opaque,
+                           Local<Boolean> is_wasm, Local<Boolean> is_module)
+    : resource_name_(resource_name),
+      resource_line_offset_(resource_line_offset),
+      resource_column_offset_(resource_column_offset),
+      options_(!resource_is_shared_cross_origin.IsEmpty() &&
+                   resource_is_shared_cross_origin->IsTrue(),
+               !resource_is_opaque.IsEmpty() && resource_is_opaque->IsTrue(),
+               !is_wasm.IsEmpty() && is_wasm->IsTrue(),
+               !is_module.IsEmpty() && is_module->IsTrue()),
+      script_id_(script_id),
+      source_map_url_(source_map_url) {}
+
+Local<Value> ScriptOrigin::ResourceName() const { return resource_name_; }
+
+
+Local<Integer> ScriptOrigin::ResourceLineOffset() const {
+  return resource_line_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ResourceColumnOffset() const {
+  return resource_column_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ScriptID() const { return script_id_; }
+
+
+Local<Value> ScriptOrigin::SourceMapUrl() const { return source_map_url_; }
+
+
+ScriptCompiler::Source::Source(Local<String> string, const ScriptOrigin& origin,
+                               CachedData* data)
+    : source_string(string),
+      resource_name(origin.ResourceName()),
+      resource_line_offset(origin.ResourceLineOffset()),
+      resource_column_offset(origin.ResourceColumnOffset()),
+      resource_options(origin.Options()),
+      source_map_url(origin.SourceMapUrl()),
+      cached_data(data) {}
+
+
+ScriptCompiler::Source::Source(Local<String> string,
+                               CachedData* data)
+    : source_string(string), cached_data(data) {}
+
+
+ScriptCompiler::Source::~Source() {
+  delete cached_data;
+}
+
+
+const ScriptCompiler::CachedData* ScriptCompiler::Source::GetCachedData()
+    const {
+  return cached_data;
+}
+
+const ScriptOriginOptions& ScriptCompiler::Source::GetResourceOptions() const {
+  return resource_options;
+}
+
+Local<Boolean> Boolean::New(Isolate* isolate, bool value) {
+  return value ? True(isolate) : False(isolate);
+}
+
+void Template::Set(Isolate* isolate, const char* name, Local<Data> value) {
+  Set(String::NewFromUtf8(isolate, name, NewStringType::kInternalized)
+          .ToLocalChecked(),
+      value);
+}
+
+
+Local<Value> Object::GetInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (instance_type == I::kJSObjectType ||
+      instance_type == I::kJSApiObjectType) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    O* value = I::ReadField<O*>(obj, offset);
+    O** result = HandleScope::CreateHandle(reinterpret_cast<HO*>(obj), value);
+    return Local<Value>(reinterpret_cast<Value*>(result));
+  }
+#endif
+  return SlowGetInternalField(index);
+}
+
+
+void* Object::GetAlignedPointerFromInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (V8_LIKELY(instance_type == I::kJSObjectType ||
+                instance_type == I::kJSApiObjectType)) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<void*>(obj, offset);
+  }
+#endif
+  return SlowGetAlignedPointerFromInternalField(index);
+}
+
+String* String::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<String*>(value);
+}
+
+
+Local<String> String::Empty(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kEmptyStringRootIndex);
+  return Local<String>(reinterpret_cast<String*>(slot));
+}
+
+
+String::ExternalStringResource* String::GetExternalStringResource() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  String::ExternalStringResource* result;
+  if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    result = reinterpret_cast<String::ExternalStringResource*>(value);
+  } else {
+    result = NULL;
+  }
+#ifdef V8_ENABLE_CHECKS
+  VerifyExternalStringResource(result);
+#endif
+  return result;
+}
+
+
+String::ExternalStringResourceBase* String::GetExternalStringResourceBase(
+    String::Encoding* encoding_out) const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  int type = I::GetInstanceType(obj) & I::kFullStringRepresentationMask;
+  *encoding_out = static_cast<Encoding>(type & I::kStringEncodingMask);
+  ExternalStringResourceBase* resource = NULL;
+  if (type == I::kExternalOneByteRepresentationTag ||
+      type == I::kExternalTwoByteRepresentationTag) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    resource = static_cast<ExternalStringResourceBase*>(value);
+  }
+#ifdef V8_ENABLE_CHECKS
+    VerifyExternalStringResourceBase(resource, *encoding_out);
+#endif
+  return resource;
+}
+
+
+bool Value::IsUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsUndefined();
+#else
+  return QuickIsUndefined();
+#endif
+}
+
+bool Value::QuickIsUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kUndefinedOddballKind);
+}
+
+
+bool Value::IsNull() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull();
+#else
+  return QuickIsNull();
+#endif
+}
+
+bool Value::QuickIsNull() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kNullOddballKind);
+}
+
+bool Value::IsNullOrUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull() || FullIsUndefined();
+#else
+  return QuickIsNullOrUndefined();
+#endif
+}
+
+bool Value::QuickIsNullOrUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  int kind = I::GetOddballKind(obj);
+  return kind == I::kNullOddballKind || kind == I::kUndefinedOddballKind;
+}
+
+bool Value::IsString() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsString();
+#else
+  return QuickIsString();
+#endif
+}
+
+bool Value::QuickIsString() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  return (I::GetInstanceType(obj) < I::kFirstNonstringType);
+}
+
+
+template <class T> Value* Value::Cast(T* value) {
+  return static_cast<Value*>(value);
+}
+
+
+Local<Boolean> Value::ToBoolean() const {
+  return ToBoolean(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Boolean>());
+}
+
+
+Local<Number> Value::ToNumber() const {
+  return ToNumber(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Number>());
+}
+
+
+Local<String> Value::ToString() const {
+  return ToString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<String> Value::ToDetailString() const {
+  return ToDetailString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<Object> Value::ToObject() const {
+  return ToObject(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Object>());
+}
+
+
+Local<Integer> Value::ToInteger() const {
+  return ToInteger(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Integer>());
+}
+
+
+Local<Uint32> Value::ToUint32() const {
+  return ToUint32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Uint32>());
+}
+
+
+Local<Int32> Value::ToInt32() const {
+  return ToInt32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Int32>());
+}
+
+
+Boolean* Boolean::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Boolean*>(value);
+}
+
+
+Name* Name::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Name*>(value);
+}
+
+
+Symbol* Symbol::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Symbol*>(value);
+}
+
+
+Number* Number::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Number*>(value);
+}
+
+
+Integer* Integer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Integer*>(value);
+}
+
+
+Int32* Int32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32*>(value);
+}
+
+
+Uint32* Uint32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32*>(value);
+}
+
+
+Date* Date::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Date*>(value);
+}
+
+
+StringObject* StringObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<StringObject*>(value);
+}
+
+
+SymbolObject* SymbolObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SymbolObject*>(value);
+}
+
+
+NumberObject* NumberObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<NumberObject*>(value);
+}
+
+
+BooleanObject* BooleanObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<BooleanObject*>(value);
+}
+
+
+RegExp* RegExp::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<RegExp*>(value);
+}
+
+
+Object* Object::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Object*>(value);
+}
+
+
+Array* Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Array*>(value);
+}
+
+
+Map* Map::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Map*>(value);
+}
+
+
+Set* Set::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Set*>(value);
+}
+
+
+Promise* Promise::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise*>(value);
+}
+
+
+Proxy* Proxy::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Proxy*>(value);
+}
+
+WasmCompiledModule* WasmCompiledModule::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<WasmCompiledModule*>(value);
+}
+
+Promise::Resolver* Promise::Resolver::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise::Resolver*>(value);
+}
+
+
+ArrayBuffer* ArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBuffer*>(value);
+}
+
+
+ArrayBufferView* ArrayBufferView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBufferView*>(value);
+}
+
+
+TypedArray* TypedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<TypedArray*>(value);
+}
+
+
+Uint8Array* Uint8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8Array*>(value);
+}
+
+
+Int8Array* Int8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int8Array*>(value);
+}
+
+
+Uint16Array* Uint16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint16Array*>(value);
+}
+
+
+Int16Array* Int16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int16Array*>(value);
+}
+
+
+Uint32Array* Uint32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32Array*>(value);
+}
+
+
+Int32Array* Int32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32Array*>(value);
+}
+
+
+Float32Array* Float32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float32Array*>(value);
+}
+
+
+Float64Array* Float64Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float64Array*>(value);
+}
+
+
+Uint8ClampedArray* Uint8ClampedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8ClampedArray*>(value);
+}
+
+
+DataView* DataView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<DataView*>(value);
+}
+
+
+SharedArrayBuffer* SharedArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedArrayBuffer*>(value);
+}
+
+
+Function* Function::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Function*>(value);
+}
+
+
+External* External::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<External*>(value);
+}
+
+
+template<typename T>
+Isolate* PropertyCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+Local<Value> PropertyCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&args_[kDataIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kThisIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kHolderIndex]));
+}
+
+
+template<typename T>
+ReturnValue<T> PropertyCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&args_[kReturnValueIndex]);
+}
+
+template <typename T>
+bool PropertyCallbackInfo<T>::ShouldThrowOnError() const {
+  typedef internal::Internals I;
+  return args_[kShouldThrowOnErrorIndex] != I::IntToSmi(0);
+}
+
+
+Local<Primitive> Undefined(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kUndefinedValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Primitive> Null(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kNullValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Boolean> True(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kTrueValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+Local<Boolean> False(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kFalseValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+void Isolate::SetData(uint32_t slot, void* data) {
+  typedef internal::Internals I;
+  I::SetEmbedderData(this, slot, data);
+}
+
+
+void* Isolate::GetData(uint32_t slot) {
+  typedef internal::Internals I;
+  return I::GetEmbedderData(this, slot);
+}
+
+
+uint32_t Isolate::GetNumberOfDataSlots() {
+  typedef internal::Internals I;
+  return I::kNumIsolateDataSlots;
+}
+
+
+int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
+    int64_t change_in_bytes) {
+  typedef internal::Internals I;
+  int64_t* external_memory = reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryOffset);
+  const int64_t external_memory_limit = *reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryLimitOffset);
+  const int64_t amount = *external_memory + change_in_bytes;
+  *external_memory = amount;
+  if (change_in_bytes > 0 && amount > external_memory_limit) {
+    ReportExternalAllocationLimitReached();
+  }
+  return *external_memory;
+}
+
+Local<Value> Context::GetEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  HO* context = *reinterpret_cast<HO**>(this);
+  O** result =
+      HandleScope::CreateHandle(context, I::ReadEmbedderData<O*>(this, index));
+  return Local<Value>(reinterpret_cast<Value*>(result));
+#else
+  return SlowGetEmbedderData(index);
+#endif
+}
+
+
+void* Context::GetAlignedPointerFromEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Internals I;
+  return I::ReadEmbedderData<void*>(this, index);
+#else
+  return SlowGetAlignedPointerFromEmbedderData(index);
+#endif
+}
+
+
+void V8::SetAllowCodeGenerationFromStringsCallback(
+    AllowCodeGenerationFromStringsCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetAllowCodeGenerationFromStringsCallback(callback);
+}
+
+
+bool V8::IsDead() {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->IsDead();
+}
+
+
+bool V8::AddMessageListener(MessageCallback that, Local<Value> data) {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->AddMessageListener(that, data);
+}
+
+
+void V8::RemoveMessageListeners(MessageCallback that) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveMessageListeners(that);
+}
+
+
+void V8::SetFailedAccessCheckCallbackFunction(
+    FailedAccessCheckCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFailedAccessCheckCallbackFunction(callback);
+}
+
+
+void V8::SetCaptureStackTraceForUncaughtExceptions(
+    bool capture, int frame_limit, StackTrace::StackTraceOptions options) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetCaptureStackTraceForUncaughtExceptions(capture, frame_limit,
+                                                     options);
+}
+
+
+void V8::SetFatalErrorHandler(FatalErrorCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFatalErrorHandler(callback);
+}
+
+void V8::RemoveGCPrologueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCPrologueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+
+void V8::RemoveGCEpilogueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCEpilogueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+void V8::TerminateExecution(Isolate* isolate) { isolate->TerminateExecution(); }
+
+
+bool V8::IsExecutionTerminating(Isolate* isolate) {
+  if (isolate == NULL) {
+    isolate = Isolate::GetCurrent();
+  }
+  return isolate->IsExecutionTerminating();
+}
+
+
+void V8::CancelTerminateExecution(Isolate* isolate) {
+  isolate->CancelTerminateExecution();
+}
+
+
+void V8::VisitExternalResources(ExternalResourceVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitExternalResources(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(PersistentHandleVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(Isolate* isolate,
+                                  PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesForPartialDependence(Isolate* isolate,
+                                          PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesForPartialDependence(visitor);
+}
+
+/**
+ * \example shell.cc
+ * A simple shell that takes a list of expressions on the
+ * command-line and executes them.
+ */
+
+
+/**
+ * \example process.cc
+ */
+
+
+}  // namespace v8
+
+
+#undef TYPE_CHECK
+
+
+#endif  // INCLUDE_V8_H_
diff --git a/android/armeabi-v7a/include/v8/v8config.h b/android/armeabi-v7a/include/v8/v8config.h
new file mode 100644
index 00000000..964949c2
--- /dev/null
+++ b/android/armeabi-v7a/include/v8/v8config.h
@@ -0,0 +1,428 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8CONFIG_H_
+#define V8CONFIG_H_
+
+// clang-format off
+
+// Platform headers for feature detection below.
+#if defined(__ANDROID__)
+# include <sys/cdefs.h>
+#elif defined(__APPLE__)
+# include <TargetConditionals.h>
+#elif defined(__linux__)
+# include <features.h>
+#endif
+
+
+// This macro allows to test for the version of the GNU C library (or
+// a compatible C library that masquerades as glibc). It evaluates to
+// 0 if libc is not GNU libc or compatible.
+// Use like:
+//  #if V8_GLIBC_PREREQ(2, 3)
+//   ...
+//  #endif
+#if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
+# define V8_GLIBC_PREREQ(major, minor)                                    \
+    ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
+#else
+# define V8_GLIBC_PREREQ(major, minor) 0
+#endif
+
+
+// This macro allows to test for the version of the GNU C++ compiler.
+// Note that this also applies to compilers that masquerade as GCC,
+// for example clang and the Intel C++ compiler for Linux.
+// Use like:
+//  #if V8_GNUC_PREREQ(4, 3, 1)
+//   ...
+//  #endif
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)                         \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >=   \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)      \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >=      \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#else
+# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
+#endif
+
+
+
+// -----------------------------------------------------------------------------
+// Operating system detection
+//
+//  V8_OS_ANDROID       - Android
+//  V8_OS_BSD           - BSDish (Mac OS X, Net/Free/Open/DragonFlyBSD)
+//  V8_OS_CYGWIN        - Cygwin
+//  V8_OS_DRAGONFLYBSD  - DragonFlyBSD
+//  V8_OS_FREEBSD       - FreeBSD
+//  V8_OS_LINUX         - Linux
+//  V8_OS_MACOSX        - Mac OS X
+//  V8_OS_NETBSD        - NetBSD
+//  V8_OS_OPENBSD       - OpenBSD
+//  V8_OS_POSIX         - POSIX compatible (mostly everything except Windows)
+//  V8_OS_QNX           - QNX Neutrino
+//  V8_OS_SOLARIS       - Sun Solaris and OpenSolaris
+//  V8_OS_AIX           - AIX
+//  V8_OS_WIN           - Microsoft Windows
+
+#if defined(__ANDROID__)
+# define V8_OS_ANDROID 1
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__APPLE__)
+# define V8_OS_BSD 1
+# define V8_OS_MACOSX 1
+# define V8_OS_POSIX 1
+#elif defined(__CYGWIN__)
+# define V8_OS_CYGWIN 1
+# define V8_OS_POSIX 1
+#elif defined(__linux__)
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__sun)
+# define V8_OS_POSIX 1
+# define V8_OS_SOLARIS 1
+#elif defined(_AIX)
+#define V8_OS_POSIX 1
+#define V8_OS_AIX 1
+#elif defined(__FreeBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_FREEBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__DragonFly__)
+# define V8_OS_BSD 1
+# define V8_OS_DRAGONFLYBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__NetBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_NETBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__OpenBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_OPENBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__QNXNTO__)
+# define V8_OS_POSIX 1
+# define V8_OS_QNX 1
+#elif defined(_WIN32)
+# define V8_OS_WIN 1
+#endif
+
+
+// -----------------------------------------------------------------------------
+// C library detection
+//
+//  V8_LIBC_MSVCRT  - MSVC libc
+//  V8_LIBC_BIONIC  - Bionic libc
+//  V8_LIBC_BSD     - BSD libc derivate
+//  V8_LIBC_GLIBC   - GNU C library
+//  V8_LIBC_UCLIBC  - uClibc
+//
+// Note that testing for libc must be done using #if not #ifdef. For example,
+// to test for the GNU C library, use:
+//  #if V8_LIBC_GLIBC
+//   ...
+//  #endif
+
+#if defined (_MSC_VER)
+# define V8_LIBC_MSVCRT 1
+#elif defined(__BIONIC__)
+# define V8_LIBC_BIONIC 1
+# define V8_LIBC_BSD 1
+#elif defined(__UCLIBC__)
+// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
+# define V8_LIBC_UCLIBC 1
+#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
+# define V8_LIBC_GLIBC 1
+#else
+# define V8_LIBC_BSD V8_OS_BSD
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Compiler detection
+//
+//  V8_CC_GNU     - GCC, or clang in gcc mode
+//  V8_CC_INTEL   - Intel C++
+//  V8_CC_MINGW   - Minimalist GNU for Windows
+//  V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
+//  V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
+//  V8_CC_MSVC    - Microsoft Visual C/C++, or clang in cl.exe mode
+//
+// C++11 feature detection
+//
+//  V8_HAS_CXX11_ALIGNAS        - alignas specifier supported
+//  V8_HAS_CXX11_ALIGNOF        - alignof(type) operator supported
+//
+// Compiler-specific feature detection
+//
+//  V8_HAS___ALIGNOF                    - __alignof(type) operator supported
+//  V8_HAS___ALIGNOF__                  - __alignof__(type) operator supported
+//  V8_HAS_ATTRIBUTE_ALIGNED            - __attribute__((aligned(n))) supported
+//  V8_HAS_ATTRIBUTE_ALWAYS_INLINE      - __attribute__((always_inline))
+//                                        supported
+//  V8_HAS_ATTRIBUTE_DEPRECATED         - __attribute__((deprecated)) supported
+//  V8_HAS_ATTRIBUTE_NOINLINE           - __attribute__((noinline)) supported
+//  V8_HAS_ATTRIBUTE_NORETURN           - __attribute__((noreturn)) supported
+//  V8_HAS_ATTRIBUTE_UNUSED             - __attribute__((unused)) supported
+//  V8_HAS_ATTRIBUTE_VISIBILITY         - __attribute__((visibility)) supported
+//  V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
+//                                        supported
+//  V8_HAS_BUILTIN_CLZ                  - __builtin_clz() supported
+//  V8_HAS_BUILTIN_CTZ                  - __builtin_ctz() supported
+//  V8_HAS_BUILTIN_EXPECT               - __builtin_expect() supported
+//  V8_HAS_BUILTIN_FRAME_ADDRESS        - __builtin_frame_address() supported
+//  V8_HAS_BUILTIN_POPCOUNT             - __builtin_popcount() supported
+//  V8_HAS_BUILTIN_SADD_OVERFLOW        - __builtin_sadd_overflow() supported
+//  V8_HAS_BUILTIN_SSUB_OVERFLOW        - __builtin_ssub_overflow() supported
+//  V8_HAS_BUILTIN_UADD_OVERFLOW        - __builtin_uadd_overflow() supported
+//  V8_HAS_DECLSPEC_ALIGN               - __declspec(align(n)) supported
+//  V8_HAS_DECLSPEC_DEPRECATED          - __declspec(deprecated) supported
+//  V8_HAS_DECLSPEC_NOINLINE            - __declspec(noinline) supported
+//  V8_HAS_DECLSPEC_SELECTANY           - __declspec(selectany) supported
+//  V8_HAS_DECLSPEC_NORETURN            - __declspec(noreturn) supported
+//  V8_HAS___FORCEINLINE                - __forceinline supported
+//
+// Note that testing for compilers and/or features must be done using #if
+// not #ifdef. For example, to test for Intel C++ Compiler, use:
+//  #if V8_CC_INTEL
+//   ...
+//  #endif
+
+#if defined(__clang__)
+
+#if defined(__GNUC__)  // Clang in gcc mode.
+# define V8_CC_GNU 1
+#endif
+
+// Clang defines __alignof__ as alias for __alignof
+# define V8_HAS___ALIGNOF 1
+# define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
+# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
+# define V8_HAS_ATTRIBUTE_NORETURN (__has_attribute(noreturn))
+# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (__has_attribute(warn_unused_result))
+
+# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
+# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
+# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
+# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
+# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
+# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
+# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
+
+# define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
+
+#elif defined(__GNUC__)
+
+# define V8_CC_GNU 1
+# if defined(__INTEL_COMPILER)  // Intel C++ also masquerades as GCC 3.2.0
+#  define V8_CC_INTEL 1
+# endif
+# if defined(__MINGW32__)
+#  define V8_CC_MINGW32 1
+# endif
+# if defined(__MINGW64__)
+#  define V8_CC_MINGW64 1
+# endif
+# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
+
+# define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
+// always_inline is available in gcc 4.0 but not very reliable until 4.4.
+// Works around "sorry, unimplemented: inlining failed" build errors with
+// older compilers.
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (V8_GNUC_PREREQ(4, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
+# define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_NORETURN (V8_GNUC_PREREQ(2, 5, 0))
+# define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
+
+# define V8_HAS_BUILTIN_CLZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_CTZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
+
+# if __cplusplus >= 201103L
+#  define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
+#  define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
+# endif
+#endif
+
+#if defined(_MSC_VER)
+# define V8_CC_MSVC 1
+# define V8_HAS___ALIGNOF 1
+
+# define V8_HAS_DECLSPEC_ALIGN 1
+# define V8_HAS_DECLSPEC_DEPRECATED 1
+# define V8_HAS_DECLSPEC_NOINLINE 1
+# define V8_HAS_DECLSPEC_SELECTANY 1
+# define V8_HAS_DECLSPEC_NORETURN 1
+
+# define V8_HAS___FORCEINLINE 1
+
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Helper macros
+
+// A macro used to make better inlining. Don't bother for debug builds.
+// Use like:
+//   V8_INLINE int GetZero() { return 0; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
+# define V8_INLINE inline __attribute__((always_inline))
+#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
+# define V8_INLINE __forceinline
+#else
+# define V8_INLINE inline
+#endif
+
+
+// A macro used to tell the compiler to never inline a particular function.
+// Don't bother for debug builds.
+// Use like:
+//   V8_NOINLINE int GetMinusOne() { return -1; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
+# define V8_NOINLINE __attribute__((noinline))
+#elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
+# define V8_NOINLINE __declspec(noinline)
+#else
+# define V8_NOINLINE /* NOT SUPPORTED */
+#endif
+
+
+// A macro used to tell the compiler that a particular function never returns.
+// Use like:
+//   V8_NORETURN void MyAbort() { abort(); }
+#if V8_HAS_ATTRIBUTE_NORETURN
+# define V8_NORETURN __attribute__((noreturn))
+#elif V8_HAS_DECLSPEC_NORETURN
+# define V8_NORETURN __declspec(noreturn)
+#else
+# define V8_NORETURN /* NOT SUPPORTED */
+#endif
+
+
+// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
+#if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATED(message, declarator) declarator
+#endif
+
+
+// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
+#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) && \
+    V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATE_SOON(message, declarator) declarator
+#endif
+
+
+// A macro to provide the compiler with branch prediction information.
+#if V8_HAS_BUILTIN_EXPECT
+# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
+# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
+#else
+# define V8_UNLIKELY(condition) (condition)
+# define V8_LIKELY(condition) (condition)
+#endif
+
+
+// This macro allows to specify memory alignment for structs, classes, etc.
+// Use like:
+//   class V8_ALIGNED(16) MyClass { ... };
+//   V8_ALIGNED(32) int array[42];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNED(n) alignas(n)
+#elif V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNED(n) __attribute__((aligned(n)))
+#elif V8_HAS_DECLSPEC_ALIGN
+# define V8_ALIGNED(n) __declspec(align(n))
+#else
+# define V8_ALIGNED(n) /* NOT SUPPORTED */
+#endif
+
+
+// This macro is similar to V8_ALIGNED(), but takes a type instead of size
+// in bytes. If the compiler does not supports using the alignment of the
+// |type|, it will align according to the |alignment| instead. For example,
+// Visual Studio C++ cannot combine __declspec(align) and __alignof. The
+// |alignment| must be a literal that is used as a kind of worst-case fallback
+// alignment.
+// Use like:
+//   struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
+//   V8_ALIGNAS(double, 8) int array[100];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNAS(type, alignment) alignas(type)
+#elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
+#else
+# define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
+#endif
+
+
+// This macro returns alignment in bytes (an integer power of two) required for
+// any instance of the given type, which is either complete type, an array type,
+// or a reference type.
+// Use like:
+//   size_t alignment = V8_ALIGNOF(double);
+#if V8_HAS_CXX11_ALIGNOF
+# define V8_ALIGNOF(type) alignof(type)
+#elif V8_HAS___ALIGNOF
+# define V8_ALIGNOF(type) __alignof(type)
+#elif V8_HAS___ALIGNOF__
+# define V8_ALIGNOF(type) __alignof__(type)
+#else
+// Note that alignment of a type within a struct can be less than the
+// alignment of the type stand-alone (because of ancient ABIs), so this
+// should only be used as a last resort.
+namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
+# define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
+#endif
+
+// Annotate a function indicating the caller must examine the return value.
+// Use like:
+//   int foo() WARN_UNUSED_RESULT;
+#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
+#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
+#endif
+
+// clang-format on
+
+#endif  // V8CONFIG_H_
diff --git a/android/armeabi-v7a/libinspector.a b/android/armeabi-v7a/libinspector.a
new file mode 100644
index 00000000..940a4626
Binary files /dev/null and b/android/armeabi-v7a/libinspector.a differ
diff --git a/android/armeabi-v7a/libv8_base.a b/android/armeabi-v7a/libv8_base.a
new file mode 100644
index 00000000..30789308
Binary files /dev/null and b/android/armeabi-v7a/libv8_base.a differ
diff --git a/android/armeabi-v7a/libv8_builtins_generators.a b/android/armeabi-v7a/libv8_builtins_generators.a
new file mode 100644
index 00000000..a6ef389d
Binary files /dev/null and b/android/armeabi-v7a/libv8_builtins_generators.a differ
diff --git a/android/armeabi-v7a/libv8_builtins_setup.a b/android/armeabi-v7a/libv8_builtins_setup.a
new file mode 100644
index 00000000..b4288166
Binary files /dev/null and b/android/armeabi-v7a/libv8_builtins_setup.a differ
diff --git a/android/armeabi-v7a/libv8_libbase.a b/android/armeabi-v7a/libv8_libbase.a
new file mode 100644
index 00000000..db29b217
Binary files /dev/null and b/android/armeabi-v7a/libv8_libbase.a differ
diff --git a/android/armeabi-v7a/libv8_libplatform.a b/android/armeabi-v7a/libv8_libplatform.a
new file mode 100644
index 00000000..ff16539e
Binary files /dev/null and b/android/armeabi-v7a/libv8_libplatform.a differ
diff --git a/android/armeabi-v7a/libv8_libsampler.a b/android/armeabi-v7a/libv8_libsampler.a
new file mode 100644
index 00000000..0d1530e0
Binary files /dev/null and b/android/armeabi-v7a/libv8_libsampler.a differ
diff --git a/android/armeabi-v7a/libv8_nosnapshot.a b/android/armeabi-v7a/libv8_nosnapshot.a
new file mode 100644
index 00000000..7aa60d61
Binary files /dev/null and b/android/armeabi-v7a/libv8_nosnapshot.a differ
diff --git a/android/armeabi/include/v8/libplatform/libplatform-export.h b/android/armeabi/include/v8/libplatform/libplatform-export.h
new file mode 100644
index 00000000..15618434
--- /dev/null
+++ b/android/armeabi/include/v8/libplatform/libplatform-export.h
@@ -0,0 +1,29 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+
+#if defined(_WIN32)
+
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllexport)
+#elif USING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllimport)
+#else
+#define V8_PLATFORM_EXPORT
+#endif  // BUILDING_V8_PLATFORM_SHARED
+
+#else  // defined(_WIN32)
+
+// Setup for Linux shared library export.
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __attribute__((visibility("default")))
+#else
+#define V8_PLATFORM_EXPORT
+#endif
+
+#endif  // defined(_WIN32)
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
diff --git a/android/armeabi/include/v8/libplatform/libplatform.h b/android/armeabi/include/v8/libplatform/libplatform.h
new file mode 100644
index 00000000..e9450456
--- /dev/null
+++ b/android/armeabi/include/v8/libplatform/libplatform.h
@@ -0,0 +1,78 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_H_
+
+#include "libplatform/libplatform-export.h"
+#include "libplatform/v8-tracing.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+namespace platform {
+
+enum class IdleTaskSupport { kDisabled, kEnabled };
+enum class InProcessStackDumping { kDisabled, kEnabled };
+
+enum class MessageLoopBehavior : bool {
+  kDoNotWait = false,
+  kWaitForWork = true
+};
+
+/**
+ * Returns a new instance of the default v8::Platform implementation.
+ *
+ * The caller will take ownership of the returned pointer. |thread_pool_size|
+ * is the number of worker threads to allocate for background jobs. If a value
+ * of zero is passed, a suitable default based on the current number of
+ * processors online will be chosen.
+ * If |idle_task_support| is enabled then the platform will accept idle
+ * tasks (IdleTasksEnabled will return true) and will rely on the embedder
+ * calling v8::platform::RunIdleTasks to process the idle tasks.
+ */
+V8_PLATFORM_EXPORT v8::Platform* CreateDefaultPlatform(
+    int thread_pool_size = 0,
+    IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
+    InProcessStackDumping in_process_stack_dumping =
+        InProcessStackDumping::kEnabled);
+
+/**
+ * Pumps the message loop for the given isolate.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * Returns true if a task was executed, and false otherwise. Unless requested
+ * through the |behavior| parameter, this call does not block if no task is
+ * pending. The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT bool PumpMessageLoop(
+    v8::Platform* platform, v8::Isolate* isolate,
+    MessageLoopBehavior behavior = MessageLoopBehavior::kDoNotWait);
+
+V8_PLATFORM_EXPORT void EnsureEventLoopInitialized(v8::Platform* platform,
+                                                   v8::Isolate* isolate);
+
+/**
+ * Runs pending idle tasks for at most |idle_time_in_seconds| seconds.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * This call does not block if no task is pending. The |platform| has to be
+ * created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void RunIdleTasks(v8::Platform* platform,
+                                     v8::Isolate* isolate,
+                                     double idle_time_in_seconds);
+
+/**
+ * Attempts to set the tracing controller for the given platform.
+ *
+ * The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void SetTracingController(
+    v8::Platform* platform,
+    v8::platform::tracing::TracingController* tracing_controller);
+
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_H_
diff --git a/android/armeabi/include/v8/libplatform/v8-tracing.h b/android/armeabi/include/v8/libplatform/v8-tracing.h
new file mode 100644
index 00000000..902f8ea9
--- /dev/null
+++ b/android/armeabi/include/v8/libplatform/v8-tracing.h
@@ -0,0 +1,270 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_V8_TRACING_H_
+#define V8_LIBPLATFORM_V8_TRACING_H_
+
+#include <fstream>
+#include <memory>
+#include <unordered_set>
+#include <vector>
+
+#include "libplatform/libplatform-export.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+
+namespace base {
+class Mutex;
+}  // namespace base
+
+namespace platform {
+namespace tracing {
+
+const int kTraceMaxNumArgs = 2;
+
+class V8_PLATFORM_EXPORT TraceObject {
+ public:
+  union ArgValue {
+    bool as_bool;
+    uint64_t as_uint;
+    int64_t as_int;
+    double as_double;
+    const void* as_pointer;
+    const char* as_string;
+  };
+
+  TraceObject() {}
+  ~TraceObject();
+  void Initialize(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateDuration();
+  void InitializeForTesting(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags, int pid, int tid, int64_t ts, int64_t tts,
+      uint64_t duration, uint64_t cpu_duration);
+
+  int pid() const { return pid_; }
+  int tid() const { return tid_; }
+  char phase() const { return phase_; }
+  const uint8_t* category_enabled_flag() const {
+    return category_enabled_flag_;
+  }
+  const char* name() const { return name_; }
+  const char* scope() const { return scope_; }
+  uint64_t id() const { return id_; }
+  uint64_t bind_id() const { return bind_id_; }
+  int num_args() const { return num_args_; }
+  const char** arg_names() { return arg_names_; }
+  uint8_t* arg_types() { return arg_types_; }
+  ArgValue* arg_values() { return arg_values_; }
+  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables() {
+    return arg_convertables_;
+  }
+  unsigned int flags() const { return flags_; }
+  int64_t ts() { return ts_; }
+  int64_t tts() { return tts_; }
+  uint64_t duration() { return duration_; }
+  uint64_t cpu_duration() { return cpu_duration_; }
+
+ private:
+  int pid_;
+  int tid_;
+  char phase_;
+  const char* name_;
+  const char* scope_;
+  const uint8_t* category_enabled_flag_;
+  uint64_t id_;
+  uint64_t bind_id_;
+  int num_args_ = 0;
+  const char* arg_names_[kTraceMaxNumArgs];
+  uint8_t arg_types_[kTraceMaxNumArgs];
+  ArgValue arg_values_[kTraceMaxNumArgs];
+  std::unique_ptr<v8::ConvertableToTraceFormat>
+      arg_convertables_[kTraceMaxNumArgs];
+  char* parameter_copy_storage_ = nullptr;
+  unsigned int flags_;
+  int64_t ts_;
+  int64_t tts_;
+  uint64_t duration_;
+  uint64_t cpu_duration_;
+
+  // Disallow copy and assign
+  TraceObject(const TraceObject&) = delete;
+  void operator=(const TraceObject&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceWriter {
+ public:
+  TraceWriter() {}
+  virtual ~TraceWriter() {}
+  virtual void AppendTraceEvent(TraceObject* trace_event) = 0;
+  virtual void Flush() = 0;
+
+  static TraceWriter* CreateJSONTraceWriter(std::ostream& stream);
+
+ private:
+  // Disallow copy and assign
+  TraceWriter(const TraceWriter&) = delete;
+  void operator=(const TraceWriter&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBufferChunk {
+ public:
+  explicit TraceBufferChunk(uint32_t seq);
+
+  void Reset(uint32_t new_seq);
+  bool IsFull() const { return next_free_ == kChunkSize; }
+  TraceObject* AddTraceEvent(size_t* event_index);
+  TraceObject* GetEventAt(size_t index) { return &chunk_[index]; }
+
+  uint32_t seq() const { return seq_; }
+  size_t size() const { return next_free_; }
+
+  static const size_t kChunkSize = 64;
+
+ private:
+  size_t next_free_ = 0;
+  TraceObject chunk_[kChunkSize];
+  uint32_t seq_;
+
+  // Disallow copy and assign
+  TraceBufferChunk(const TraceBufferChunk&) = delete;
+  void operator=(const TraceBufferChunk&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBuffer {
+ public:
+  TraceBuffer() {}
+  virtual ~TraceBuffer() {}
+
+  virtual TraceObject* AddTraceEvent(uint64_t* handle) = 0;
+  virtual TraceObject* GetEventByHandle(uint64_t handle) = 0;
+  virtual bool Flush() = 0;
+
+  static const size_t kRingBufferChunks = 1024;
+
+  static TraceBuffer* CreateTraceBufferRingBuffer(size_t max_chunks,
+                                                  TraceWriter* trace_writer);
+
+ private:
+  // Disallow copy and assign
+  TraceBuffer(const TraceBuffer&) = delete;
+  void operator=(const TraceBuffer&) = delete;
+};
+
+// Options determines how the trace buffer stores data.
+enum TraceRecordMode {
+  // Record until the trace buffer is full.
+  RECORD_UNTIL_FULL,
+
+  // Record until the user ends the trace. The trace buffer is a fixed size
+  // and we use it as a ring buffer during recording.
+  RECORD_CONTINUOUSLY,
+
+  // Record until the trace buffer is full, but with a huge buffer size.
+  RECORD_AS_MUCH_AS_POSSIBLE,
+
+  // Echo to console. Events are discarded.
+  ECHO_TO_CONSOLE,
+};
+
+class V8_PLATFORM_EXPORT TraceConfig {
+ public:
+  typedef std::vector<std::string> StringList;
+
+  static TraceConfig* CreateDefaultTraceConfig();
+
+  TraceConfig() : enable_systrace_(false), enable_argument_filter_(false) {}
+  TraceRecordMode GetTraceRecordMode() const { return record_mode_; }
+  bool IsSystraceEnabled() const { return enable_systrace_; }
+  bool IsArgumentFilterEnabled() const { return enable_argument_filter_; }
+
+  void SetTraceRecordMode(TraceRecordMode mode) { record_mode_ = mode; }
+  void EnableSystrace() { enable_systrace_ = true; }
+  void EnableArgumentFilter() { enable_argument_filter_ = true; }
+
+  void AddIncludedCategory(const char* included_category);
+
+  bool IsCategoryGroupEnabled(const char* category_group) const;
+
+ private:
+  TraceRecordMode record_mode_;
+  bool enable_systrace_ : 1;
+  bool enable_argument_filter_ : 1;
+  StringList included_categories_;
+
+  // Disallow copy and assign
+  TraceConfig(const TraceConfig&) = delete;
+  void operator=(const TraceConfig&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TracingController {
+ public:
+  enum Mode { DISABLED = 0, RECORDING_MODE };
+
+  // The pointer returned from GetCategoryGroupEnabledInternal() points to a
+  // value with zero or more of the following bits. Used in this class only.
+  // The TRACE_EVENT macros should only use the value as a bool.
+  // These values must be in sync with macro values in TraceEvent.h in Blink.
+  enum CategoryGroupEnabledFlags {
+    // Category group enabled for the recording mode.
+    ENABLED_FOR_RECORDING = 1 << 0,
+    // Category group enabled by SetEventCallbackEnabled().
+    ENABLED_FOR_EVENT_CALLBACK = 1 << 2,
+    // Category group enabled to export events to ETW.
+    ENABLED_FOR_ETW_EXPORT = 1 << 3
+  };
+
+  TracingController();
+  ~TracingController();
+  void Initialize(TraceBuffer* trace_buffer);
+  const uint8_t* GetCategoryGroupEnabled(const char* category_group);
+  static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
+  uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                const char* name, uint64_t handle);
+
+  void StartTracing(TraceConfig* trace_config);
+  void StopTracing();
+
+  void AddTraceStateObserver(Platform::TraceStateObserver* observer);
+  void RemoveTraceStateObserver(Platform::TraceStateObserver* observer);
+
+ private:
+  const uint8_t* GetCategoryGroupEnabledInternal(const char* category_group);
+  void UpdateCategoryGroupEnabledFlag(size_t category_index);
+  void UpdateCategoryGroupEnabledFlags();
+
+  std::unique_ptr<TraceBuffer> trace_buffer_;
+  std::unique_ptr<TraceConfig> trace_config_;
+  std::unique_ptr<base::Mutex> mutex_;
+  std::unordered_set<Platform::TraceStateObserver*> observers_;
+  Mode mode_ = DISABLED;
+
+  // Disallow copy and assign
+  TracingController(const TracingController&) = delete;
+  void operator=(const TracingController&) = delete;
+};
+
+}  // namespace tracing
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_V8_TRACING_H_
diff --git a/android/armeabi/include/v8/v8-debug.h b/android/armeabi/include/v8/v8-debug.h
new file mode 100644
index 00000000..54c0f216
--- /dev/null
+++ b/android/armeabi/include/v8/v8-debug.h
@@ -0,0 +1,255 @@
+// Copyright 2008 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_DEBUG_H_
+#define V8_V8_DEBUG_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * ATTENTION: The debugger API exposed by this file is deprecated and will be
+ *            removed by the end of 2017. Please use the V8 inspector declared
+ *            in include/v8-inspector.h instead.
+ */
+namespace v8 {
+
+// Debug events which can occur in the V8 JavaScript engine.
+enum DebugEvent {
+  Break = 1,
+  Exception = 2,
+  AfterCompile = 3,
+  CompileError = 4,
+  AsyncTaskEvent = 5,
+};
+
+class V8_EXPORT Debug {
+ public:
+  /**
+   * A client object passed to the v8 debugger whose ownership will be taken by
+   * it. v8 is always responsible for deleting the object.
+   */
+  class ClientData {
+   public:
+    virtual ~ClientData() {}
+  };
+
+
+  /**
+   * A message object passed to the debug message handler.
+   */
+  class Message {
+   public:
+    /**
+     * Check type of message.
+     */
+    virtual bool IsEvent() const = 0;
+    virtual bool IsResponse() const = 0;
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Indicate whether this is a response to a continue command which will
+     * start the VM running after this is processed.
+     */
+    virtual bool WillStartRunning() const = 0;
+
+    /**
+     * Access to execution state and event data. Don't store these cross
+     * callbacks as their content becomes invalid. These objects are from the
+     * debugger event that started the debug message loop.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the debugger protocol JSON.
+     */
+    virtual Local<String> GetJSON() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding request if any. This is the
+     * client_data data value passed into Debug::SendCommand along with the
+     * request that led to the message or NULL if the message is an event. The
+     * debugger takes ownership of the data and will delete it even if there is
+     * no message handler.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~Message() {}
+  };
+
+  /**
+   * An event details object passed to the debug event listener.
+   */
+  class EventDetails {
+   public:
+    /**
+     * Event type.
+     */
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Access to execution state and event data of the debug event. Don't store
+     * these cross callbacks as their content becomes invalid.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding callback when it was
+     * registered.
+     */
+    virtual Local<Value> GetCallbackData() const = 0;
+
+    /**
+     * This is now a dummy that returns nullptr.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~EventDetails() {}
+  };
+
+  /**
+   * Debug event callback function.
+   *
+   * \param event_details object providing information about the debug event
+   *
+   * A EventCallback does not take possession of the event data,
+   * and must not rely on the data persisting after the handler returns.
+   */
+  typedef void (*EventCallback)(const EventDetails& event_details);
+
+  /**
+   * This is now a no-op.
+   */
+  typedef void (*MessageHandler)(const Message& message);
+
+  V8_DEPRECATED("No longer supported", static bool SetDebugEventListener(
+                                           Isolate* isolate, EventCallback that,
+                                           Local<Value> data = Local<Value>()));
+
+  // Schedule a debugger break to happen when JavaScript code is run
+  // in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static void DebugBreak(Isolate* isolate));
+
+  // Remove scheduled debugger break in given isolate if it has not
+  // happened yet.
+  V8_DEPRECATED("No longer supported",
+                static void CancelDebugBreak(Isolate* isolate));
+
+  // Check if a debugger break is scheduled in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static bool CheckDebugBreak(Isolate* isolate));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SetMessageHandler(Isolate* isolate,
+                                              MessageHandler handler));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SendCommand(Isolate* isolate,
+                                        const uint16_t* command, int length,
+                                        ClientData* client_data = NULL));
+
+  /**
+   * Run a JavaScript function in the debugger.
+   * \param fun the function to call
+   * \param data passed as second argument to the function
+   * With this call the debugger is entered and the function specified is called
+   * with the execution state as the first argument. This makes it possible to
+   * get access to information otherwise not available during normal JavaScript
+   * execution e.g. details on stack frames. Receiver of the function call will
+   * be the debugger context global object, however this is a subject to change.
+   * The following example shows a JavaScript function which when passed to
+   * v8::Debug::Call will return the current line of JavaScript execution.
+   *
+   * \code
+   *   function frame_source_line(exec_state) {
+   *     return exec_state.frame(0).sourceLine();
+   *   }
+   * \endcode
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Value> Call(
+                    Local<Context> context, v8::Local<v8::Function> fun,
+                    Local<Value> data = Local<Value>()));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void ProcessDebugMessages(Isolate* isolate));
+
+  /**
+   * Debugger is running in its own context which is entered while debugger
+   * messages are being dispatched. This is an explicit getter for this
+   * debugger context. Note that the content of the debugger context is subject
+   * to change. The Context exists only when the debugger is active, i.e. at
+   * least one DebugEventListener or MessageHandler is set.
+   */
+  V8_DEPRECATED("Use v8-inspector",
+                static Local<Context> GetDebugContext(Isolate* isolate));
+
+  /**
+   * While in the debug context, this method returns the top-most non-debug
+   * context, if it exists.
+   */
+  V8_DEPRECATED(
+      "No longer supported",
+      static MaybeLocal<Context> GetDebuggedContext(Isolate* isolate));
+
+  /**
+   * Enable/disable LiveEdit functionality for the given Isolate
+   * (default Isolate if not provided). V8 will abort if LiveEdit is
+   * unexpectedly used. LiveEdit is enabled by default.
+   */
+  V8_DEPRECATED("No longer supported",
+                static void SetLiveEditEnabled(Isolate* isolate, bool enable));
+
+  /**
+   * Returns array of internal properties specific to the value type. Result has
+   * the following format: [<name>, <value>,...,<name>, <value>]. Result array
+   * will be allocated in the current context.
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Array> GetInternalProperties(
+                    Isolate* isolate, Local<Value> value));
+
+  /**
+   * Defines if the ES2015 tail call elimination feature is enabled or not.
+   * The change of this flag triggers deoptimization of all functions that
+   * contain calls at tail position.
+   */
+  V8_DEPRECATED("No longer supported",
+                static bool IsTailCallEliminationEnabled(Isolate* isolate));
+  V8_DEPRECATED("No longer supported",
+                static void SetTailCallEliminationEnabled(Isolate* isolate,
+                                                          bool enabled));
+};
+
+
+}  // namespace v8
+
+
+#undef EXPORT
+
+
+#endif  // V8_V8_DEBUG_H_
diff --git a/android/armeabi/include/v8/v8-inspector-protocol.h b/android/armeabi/include/v8/v8-inspector-protocol.h
new file mode 100644
index 00000000..612a2ebc
--- /dev/null
+++ b/android/armeabi/include/v8/v8-inspector-protocol.h
@@ -0,0 +1,13 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_PROTOCOL_H_
+#define V8_V8_INSPECTOR_PROTOCOL_H_
+
+#include "inspector/Debugger.h"  // NOLINT(build/include)
+#include "inspector/Runtime.h"   // NOLINT(build/include)
+#include "inspector/Schema.h"    // NOLINT(build/include)
+#include "v8-inspector.h"        // NOLINT(build/include)
+
+#endif  // V8_V8_INSPECTOR_PROTOCOL_H_
diff --git a/android/armeabi/include/v8/v8-inspector.h b/android/armeabi/include/v8/v8-inspector.h
new file mode 100644
index 00000000..43bf3b4f
--- /dev/null
+++ b/android/armeabi/include/v8/v8-inspector.h
@@ -0,0 +1,267 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_H_
+#define V8_V8_INSPECTOR_H_
+
+#include <stdint.h>
+#include <cctype>
+
+#include <memory>
+
+#include "v8.h"  // NOLINT(build/include)
+
+namespace v8_inspector {
+
+namespace protocol {
+namespace Debugger {
+namespace API {
+class SearchMatch;
+}
+}
+namespace Runtime {
+namespace API {
+class RemoteObject;
+class StackTrace;
+}
+}
+namespace Schema {
+namespace API {
+class Domain;
+}
+}
+}  // namespace protocol
+
+class V8_EXPORT StringView {
+ public:
+  StringView() : m_is8Bit(true), m_length(0), m_characters8(nullptr) {}
+
+  StringView(const uint8_t* characters, size_t length)
+      : m_is8Bit(true), m_length(length), m_characters8(characters) {}
+
+  StringView(const uint16_t* characters, size_t length)
+      : m_is8Bit(false), m_length(length), m_characters16(characters) {}
+
+  bool is8Bit() const { return m_is8Bit; }
+  size_t length() const { return m_length; }
+
+  // TODO(dgozman): add DCHECK(m_is8Bit) to accessors once platform can be used
+  // here.
+  const uint8_t* characters8() const { return m_characters8; }
+  const uint16_t* characters16() const { return m_characters16; }
+
+ private:
+  bool m_is8Bit;
+  size_t m_length;
+  union {
+    const uint8_t* m_characters8;
+    const uint16_t* m_characters16;
+  };
+};
+
+class V8_EXPORT StringBuffer {
+ public:
+  virtual ~StringBuffer() {}
+  virtual const StringView& string() = 0;
+  // This method copies contents.
+  static std::unique_ptr<StringBuffer> create(const StringView&);
+};
+
+class V8_EXPORT V8ContextInfo {
+ public:
+  V8ContextInfo(v8::Local<v8::Context> context, int contextGroupId,
+                const StringView& humanReadableName)
+      : context(context),
+        contextGroupId(contextGroupId),
+        humanReadableName(humanReadableName),
+        hasMemoryOnConsole(false) {}
+
+  v8::Local<v8::Context> context;
+  // Each v8::Context is a part of a group. The group id must be non-zero.
+  int contextGroupId;
+  StringView humanReadableName;
+  StringView origin;
+  StringView auxData;
+  bool hasMemoryOnConsole;
+
+  static int executionContextId(v8::Local<v8::Context> context);
+
+ private:
+  // Disallow copying and allocating this one.
+  enum NotNullTagEnum { NotNullLiteral };
+  void* operator new(size_t) = delete;
+  void* operator new(size_t, NotNullTagEnum, void*) = delete;
+  void* operator new(size_t, void*) = delete;
+  V8ContextInfo(const V8ContextInfo&) = delete;
+  V8ContextInfo& operator=(const V8ContextInfo&) = delete;
+};
+
+class V8_EXPORT V8StackTrace {
+ public:
+  virtual bool isEmpty() const = 0;
+  virtual StringView topSourceURL() const = 0;
+  virtual int topLineNumber() const = 0;
+  virtual int topColumnNumber() const = 0;
+  virtual StringView topScriptId() const = 0;
+  virtual StringView topFunctionName() const = 0;
+
+  virtual ~V8StackTrace() {}
+  virtual std::unique_ptr<protocol::Runtime::API::StackTrace>
+  buildInspectorObject() const = 0;
+  virtual std::unique_ptr<StringBuffer> toString() const = 0;
+
+  // Safe to pass between threads, drops async chain.
+  virtual std::unique_ptr<V8StackTrace> clone() = 0;
+};
+
+class V8_EXPORT V8InspectorSession {
+ public:
+  virtual ~V8InspectorSession() {}
+
+  // Cross-context inspectable values (DOM nodes in different worlds, etc.).
+  class V8_EXPORT Inspectable {
+   public:
+    virtual v8::Local<v8::Value> get(v8::Local<v8::Context>) = 0;
+    virtual ~Inspectable() {}
+  };
+  virtual void addInspectedObject(std::unique_ptr<Inspectable>) = 0;
+
+  // Dispatching protocol messages.
+  static bool canDispatchMethod(const StringView& method);
+  virtual void dispatchProtocolMessage(const StringView& message) = 0;
+  virtual std::unique_ptr<StringBuffer> stateJSON() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Schema::API::Domain>>
+  supportedDomains() = 0;
+
+  // Debugger actions.
+  virtual void schedulePauseOnNextStatement(const StringView& breakReason,
+                                            const StringView& breakDetails) = 0;
+  virtual void cancelPauseOnNextStatement() = 0;
+  virtual void breakProgram(const StringView& breakReason,
+                            const StringView& breakDetails) = 0;
+  virtual void setSkipAllPauses(bool) = 0;
+  virtual void resume() = 0;
+  virtual void stepOver() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Debugger::API::SearchMatch>>
+  searchInTextByLines(const StringView& text, const StringView& query,
+                      bool caseSensitive, bool isRegex) = 0;
+
+  // Remote objects.
+  virtual std::unique_ptr<protocol::Runtime::API::RemoteObject> wrapObject(
+      v8::Local<v8::Context>, v8::Local<v8::Value>,
+      const StringView& groupName) = 0;
+  virtual bool unwrapObject(std::unique_ptr<StringBuffer>* error,
+                            const StringView& objectId, v8::Local<v8::Value>*,
+                            v8::Local<v8::Context>*,
+                            std::unique_ptr<StringBuffer>* objectGroup) = 0;
+  virtual void releaseObjectGroup(const StringView&) = 0;
+};
+
+class V8_EXPORT V8InspectorClient {
+ public:
+  virtual ~V8InspectorClient() {}
+
+  virtual void runMessageLoopOnPause(int contextGroupId) {}
+  virtual void quitMessageLoopOnPause() {}
+  virtual void runIfWaitingForDebugger(int contextGroupId) {}
+
+  virtual void muteMetrics(int contextGroupId) {}
+  virtual void unmuteMetrics(int contextGroupId) {}
+
+  virtual void beginUserGesture() {}
+  virtual void endUserGesture() {}
+
+  virtual std::unique_ptr<StringBuffer> valueSubtype(v8::Local<v8::Value>) {
+    return nullptr;
+  }
+  virtual bool formatAccessorsAsProperties(v8::Local<v8::Value>) {
+    return false;
+  }
+  virtual bool isInspectableHeapObject(v8::Local<v8::Object>) { return true; }
+
+  virtual v8::Local<v8::Context> ensureDefaultContextInGroup(
+      int contextGroupId) {
+    return v8::Local<v8::Context>();
+  }
+  virtual void beginEnsureAllContextsInGroup(int contextGroupId) {}
+  virtual void endEnsureAllContextsInGroup(int contextGroupId) {}
+
+  virtual void installAdditionalCommandLineAPI(v8::Local<v8::Context>,
+                                               v8::Local<v8::Object>) {}
+  virtual void consoleAPIMessage(int contextGroupId,
+                                 v8::Isolate::MessageErrorLevel level,
+                                 const StringView& message,
+                                 const StringView& url, unsigned lineNumber,
+                                 unsigned columnNumber, V8StackTrace*) {}
+  virtual v8::MaybeLocal<v8::Value> memoryInfo(v8::Isolate*,
+                                               v8::Local<v8::Context>) {
+    return v8::MaybeLocal<v8::Value>();
+  }
+
+  virtual void consoleTime(const StringView& title) {}
+  virtual void consoleTimeEnd(const StringView& title) {}
+  virtual void consoleTimeStamp(const StringView& title) {}
+  virtual void consoleClear(int contextGroupId) {}
+  virtual double currentTimeMS() { return 0; }
+  typedef void (*TimerCallback)(void*);
+  virtual void startRepeatingTimer(double, TimerCallback, void* data) {}
+  virtual void cancelTimer(void* data) {}
+
+  // TODO(dgozman): this was added to support service worker shadow page. We
+  // should not connect at all.
+  virtual bool canExecuteScripts(int contextGroupId) { return true; }
+};
+
+class V8_EXPORT V8Inspector {
+ public:
+  static std::unique_ptr<V8Inspector> create(v8::Isolate*, V8InspectorClient*);
+  virtual ~V8Inspector() {}
+
+  // Contexts instrumentation.
+  virtual void contextCreated(const V8ContextInfo&) = 0;
+  virtual void contextDestroyed(v8::Local<v8::Context>) = 0;
+  virtual void resetContextGroup(int contextGroupId) = 0;
+
+  // Various instrumentation.
+  virtual void idleStarted() = 0;
+  virtual void idleFinished() = 0;
+
+  // Async stack traces instrumentation.
+  virtual void asyncTaskScheduled(const StringView& taskName, void* task,
+                                  bool recurring) = 0;
+  virtual void asyncTaskCanceled(void* task) = 0;
+  virtual void asyncTaskStarted(void* task) = 0;
+  virtual void asyncTaskFinished(void* task) = 0;
+  virtual void allAsyncTasksCanceled() = 0;
+
+  // Exceptions instrumentation.
+  virtual unsigned exceptionThrown(
+      v8::Local<v8::Context>, const StringView& message,
+      v8::Local<v8::Value> exception, const StringView& detailedMessage,
+      const StringView& url, unsigned lineNumber, unsigned columnNumber,
+      std::unique_ptr<V8StackTrace>, int scriptId) = 0;
+  virtual void exceptionRevoked(v8::Local<v8::Context>, unsigned exceptionId,
+                                const StringView& message) = 0;
+
+  // Connection.
+  class V8_EXPORT Channel {
+   public:
+    virtual ~Channel() {}
+    virtual void sendResponse(int callId,
+                              std::unique_ptr<StringBuffer> message) = 0;
+    virtual void sendNotification(std::unique_ptr<StringBuffer> message) = 0;
+    virtual void flushProtocolNotifications() = 0;
+  };
+  virtual std::unique_ptr<V8InspectorSession> connect(
+      int contextGroupId, Channel*, const StringView& state) = 0;
+
+  // API methods.
+  virtual std::unique_ptr<V8StackTrace> createStackTrace(
+      v8::Local<v8::StackTrace>) = 0;
+  virtual std::unique_ptr<V8StackTrace> captureStackTrace(bool fullStack) = 0;
+};
+
+}  // namespace v8_inspector
+
+#endif  // V8_V8_INSPECTOR_H_
diff --git a/android/armeabi/include/v8/v8-platform.h b/android/armeabi/include/v8/v8-platform.h
new file mode 100644
index 00000000..8f6d8042
--- /dev/null
+++ b/android/armeabi/include/v8/v8-platform.h
@@ -0,0 +1,227 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PLATFORM_H_
+#define V8_V8_PLATFORM_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <memory>
+#include <string>
+
+namespace v8 {
+
+class Isolate;
+
+/**
+ * A Task represents a unit of work.
+ */
+class Task {
+ public:
+  virtual ~Task() = default;
+
+  virtual void Run() = 0;
+};
+
+/**
+ * An IdleTask represents a unit of work to be performed in idle time.
+ * The Run method is invoked with an argument that specifies the deadline in
+ * seconds returned by MonotonicallyIncreasingTime().
+ * The idle task is expected to complete by this deadline.
+ */
+class IdleTask {
+ public:
+  virtual ~IdleTask() = default;
+  virtual void Run(double deadline_in_seconds) = 0;
+};
+
+/**
+ * The interface represents complex arguments to trace events.
+ */
+class ConvertableToTraceFormat {
+ public:
+  virtual ~ConvertableToTraceFormat() = default;
+
+  /**
+   * Append the class info to the provided |out| string. The appended
+   * data must be a valid JSON object. Strings must be properly quoted, and
+   * escaped. There is no processing applied to the content after it is
+   * appended.
+   */
+  virtual void AppendAsTraceFormat(std::string* out) const = 0;
+};
+
+/**
+ * V8 Platform abstraction layer.
+ *
+ * The embedder has to provide an implementation of this interface before
+ * initializing the rest of V8.
+ */
+class Platform {
+ public:
+  /**
+   * This enum is used to indicate whether a task is potentially long running,
+   * or causes a long wait. The embedder might want to use this hint to decide
+   * whether to execute the task on a dedicated thread.
+   */
+  enum ExpectedRuntime {
+    kShortRunningTask,
+    kLongRunningTask
+  };
+
+  virtual ~Platform() = default;
+
+  /**
+   * Gets the number of threads that are used to execute background tasks. Is
+   * used to estimate the number of tasks a work package should be split into.
+   * A return value of 0 means that there are no background threads available.
+   * Note that a value of 0 won't prohibit V8 from posting tasks using
+   * |CallOnBackgroundThread|.
+   */
+  virtual size_t NumberOfAvailableBackgroundThreads() { return 0; }
+
+  /**
+   * Schedules a task to be invoked on a background thread. |expected_runtime|
+   * indicates that the task will run a long time. The Platform implementation
+   * takes ownership of |task|. There is no guarantee about order of execution
+   * of tasks wrt order of scheduling, nor is there a guarantee about the
+   * thread the task will be run on.
+   */
+  virtual void CallOnBackgroundThread(Task* task,
+                                      ExpectedRuntime expected_runtime) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate|. Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallOnForegroundThread(Isolate* isolate, Task* task) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| after the given number of seconds |delay_in_seconds|.
+   * Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallDelayedOnForegroundThread(Isolate* isolate, Task* task,
+                                             double delay_in_seconds) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| when the embedder is idle.
+   * Requires that SupportsIdleTasks(isolate) is true.
+   * Idle tasks may be reordered relative to other task types and may be
+   * starved for an arbitrarily long time if no idle time is available.
+   * The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallIdleOnForegroundThread(Isolate* isolate, IdleTask* task) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+  }
+
+  /**
+   * Returns true if idle tasks are enabled for the given |isolate|.
+   */
+  virtual bool IdleTasksEnabled(Isolate* isolate) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+    return false;
+  }
+
+  /**
+   * Monotonically increasing time in seconds from an arbitrary fixed point in
+   * the past. This function is expected to return at least
+   * millisecond-precision values. For this reason,
+   * it is recommended that the fixed point be no further in the past than
+   * the epoch.
+   **/
+  virtual double MonotonicallyIncreasingTime() = 0;
+
+  /**
+   * Called by TRACE_EVENT* macros, don't call this directly.
+   * The name parameter is a category group for example:
+   * TRACE_EVENT0("v8,parse", "V8.Parse")
+   * The pointer returned points to a value with zero or more of the bits
+   * defined in CategoryGroupEnabledFlags.
+   **/
+  virtual const uint8_t* GetCategoryGroupEnabled(const char* name) {
+    static uint8_t no = 0;
+    return &no;
+  }
+
+  /**
+   * Gets the category group name of the given category_enabled_flag pointer.
+   * Usually used while serliazing TRACE_EVENTs.
+   **/
+  virtual const char* GetCategoryGroupName(
+      const uint8_t* category_enabled_flag) {
+    static const char dummy[] = "dummy";
+    return dummy;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values, unsigned int flags) {
+    return 0;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags) {
+    return AddTraceEvent(phase, category_enabled_flag, name, scope, id, bind_id,
+                         num_args, arg_names, arg_types, arg_values, flags);
+  }
+
+  /**
+   * Sets the duration field of a COMPLETE trace event. It must be called with
+   * the handle returned from AddTraceEvent().
+   **/
+  virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                        const char* name, uint64_t handle) {}
+
+  class TraceStateObserver {
+   public:
+    virtual ~TraceStateObserver() = default;
+    virtual void OnTraceEnabled() = 0;
+    virtual void OnTraceDisabled() = 0;
+  };
+
+  /** Adds tracing state change observer. */
+  virtual void AddTraceStateObserver(TraceStateObserver*) {}
+
+  /** Removes tracing state change observer. */
+  virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
+
+  typedef void (*StackTracePrinter)();
+
+  /**
+   * Returns a function pointer that print a stack trace of the current stack
+   * on invocation. Disables printing of the stack trace if nullptr.
+   */
+  virtual StackTracePrinter GetStackTracePrinter() { return nullptr; }
+};
+
+}  // namespace v8
+
+#endif  // V8_V8_PLATFORM_H_
diff --git a/android/armeabi/include/v8/v8-profiler.h b/android/armeabi/include/v8/v8-profiler.h
new file mode 100644
index 00000000..b60d137f
--- /dev/null
+++ b/android/armeabi/include/v8/v8-profiler.h
@@ -0,0 +1,912 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PROFILER_H_
+#define V8_V8_PROFILER_H_
+
+#include <unordered_set>
+#include <vector>
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Profiler support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class HeapGraphNode;
+struct HeapStatsUpdate;
+
+typedef uint32_t SnapshotObjectId;
+
+
+struct CpuProfileDeoptFrame {
+  int script_id;
+  size_t position;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptFrame>;
+#endif
+
+namespace v8 {
+
+struct V8_EXPORT CpuProfileDeoptInfo {
+  /** A pointer to a static string owned by v8. */
+  const char* deopt_reason;
+  std::vector<CpuProfileDeoptFrame> stack;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>;
+#endif
+
+namespace v8 {
+
+/**
+ * TracingCpuProfiler monitors tracing being enabled/disabled
+ * and emits CpuProfile trace events once v8.cpu_profiler tracing category
+ * is enabled. It has no overhead unless the category is enabled.
+ */
+class V8_EXPORT TracingCpuProfiler {
+ public:
+  static std::unique_ptr<TracingCpuProfiler> Create(Isolate*);
+  virtual ~TracingCpuProfiler() = default;
+
+ protected:
+  TracingCpuProfiler() = default;
+};
+
+// TickSample captures the information collected for each sample.
+struct TickSample {
+  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
+  // include the runtime function we're calling. Externally exposed tick
+  // samples don't care.
+  enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame };
+
+  TickSample()
+      : state(OTHER),
+        pc(nullptr),
+        external_callback_entry(nullptr),
+        frames_count(0),
+        has_external_callback(false),
+        update_stats(true) {}
+
+  /**
+   * Initialize a tick sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Execution state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param update_stats Whether update the sample to the aggregated stats.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   */
+  void Init(Isolate* isolate, const v8::RegisterState& state,
+            RecordCEntryFrame record_c_entry_frame, bool update_stats,
+            bool use_simulator_reg_state = true);
+  /**
+   * Get a call stack sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Register state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   * \note GetStackSample is thread and signal safe and should only be called
+   *                      when the JS thread is paused or interrupted.
+   *                      Otherwise the behavior is undefined.
+   */
+  static bool GetStackSample(Isolate* isolate, v8::RegisterState* state,
+                             RecordCEntryFrame record_c_entry_frame,
+                             void** frames, size_t frames_limit,
+                             v8::SampleInfo* sample_info,
+                             bool use_simulator_reg_state = true);
+  StateTag state;  // The state of the VM.
+  void* pc;        // Instruction pointer.
+  union {
+    void* tos;  // Top stack value (*sp).
+    void* external_callback_entry;
+  };
+  static const unsigned kMaxFramesCountLog2 = 8;
+  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
+  void* stack[kMaxFramesCount];                 // Call stack.
+  unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
+  bool has_external_callback : 1;
+  bool update_stats : 1;  // Whether the sample should update aggregated stats.
+};
+
+/**
+ * CpuProfileNode represents a node in a call graph.
+ */
+class V8_EXPORT CpuProfileNode {
+ public:
+  struct LineTick {
+    /** The 1-based number of the source line where the function originates. */
+    int line;
+
+    /** The count of samples associated with the source line. */
+    unsigned int hit_count;
+  };
+
+  /** Returns function name (empty string for anonymous functions.) */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns function name (empty string for anonymous functions.)
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetFunctionNameStr() const;
+
+  /** Returns id of the script where function is located. */
+  int GetScriptId() const;
+
+  /** Returns resource name for script from where the function originates. */
+  Local<String> GetScriptResourceName() const;
+
+  /**
+   * Returns resource name for script from where the function originates.
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetScriptResourceNameStr() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the function originates.
+   * kNoLineNumberInfo if no line number information is available.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns 1-based number of the column where the function originates.
+   * kNoColumnNumberInfo if no column number information is available.
+   */
+  int GetColumnNumber() const;
+
+  /**
+   * Returns the number of the function's source lines that collect the samples.
+   */
+  unsigned int GetHitLineCount() const;
+
+  /** Returns the set of source lines that collect the samples.
+   *  The caller allocates buffer and responsible for releasing it.
+   *  True if all available entries are copied, otherwise false.
+   *  The function copies nothing if buffer is not large enough.
+   */
+  bool GetLineTicks(LineTick* entries, unsigned int length) const;
+
+  /** Returns bailout reason for the function
+    * if the optimization was disabled for it.
+    */
+  const char* GetBailoutReason() const;
+
+  /**
+    * Returns the count of samples where the function was currently executing.
+    */
+  unsigned GetHitCount() const;
+
+  /** Returns function entry UID. */
+  V8_DEPRECATE_SOON(
+      "Use GetScriptId, GetLineNumber, and GetColumnNumber instead.",
+      unsigned GetCallUid() const);
+
+  /** Returns id of the node. The id is unique within the tree */
+  unsigned GetNodeId() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child node by index. */
+  const CpuProfileNode* GetChild(int index) const;
+
+  /** Retrieves deopt infos for the node. */
+  const std::vector<CpuProfileDeoptInfo>& GetDeoptInfos() const;
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * CpuProfile contains a CPU profile in a form of top-down call tree
+ * (from main() down to functions that do all the work).
+ */
+class V8_EXPORT CpuProfile {
+ public:
+  /** Returns CPU profile title. */
+  Local<String> GetTitle() const;
+
+  /** Returns the root node of the top down call tree. */
+  const CpuProfileNode* GetTopDownRoot() const;
+
+  /**
+   * Returns number of samples recorded. The samples are not recorded unless
+   * |record_samples| parameter of CpuProfiler::StartCpuProfiling is true.
+   */
+  int GetSamplesCount() const;
+
+  /**
+   * Returns profile node corresponding to the top frame the sample at
+   * the given index.
+   */
+  const CpuProfileNode* GetSample(int index) const;
+
+  /**
+   * Returns the timestamp of the sample. The timestamp is the number of
+   * microseconds since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetSampleTimestamp(int index) const;
+
+  /**
+   * Returns time when the profile recording was started (in microseconds)
+   * since some unspecified starting point.
+   */
+  int64_t GetStartTime() const;
+
+  /**
+   * Returns time when the profile recording was stopped (in microseconds)
+   * since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetEndTime() const;
+
+  /**
+   * Deletes the profile and removes it from CpuProfiler's list.
+   * All pointers to nodes previously returned become invalid.
+   */
+  void Delete();
+};
+
+/**
+ * Interface for controlling CPU profiling. Instance of the
+ * profiler can be created using v8::CpuProfiler::New method.
+ */
+class V8_EXPORT CpuProfiler {
+ public:
+  /**
+   * Creates a new CPU profiler for the |isolate|. The isolate must be
+   * initialized. The profiler object must be disposed after use by calling
+   * |Dispose| method.
+   */
+  static CpuProfiler* New(Isolate* isolate);
+
+  /**
+   * Disposes the CPU profiler object.
+   */
+  void Dispose();
+
+  /**
+   * Changes default CPU profiler sampling interval to the specified number
+   * of microseconds. Default interval is 1000us. This method must be called
+   * when there are no profiles being recorded.
+   */
+  void SetSamplingInterval(int us);
+
+  /**
+   * Starts collecting CPU profile. Title may be an empty string. It
+   * is allowed to have several profiles being collected at
+   * once. Attempts to start collecting several profiles with the same
+   * title are silently ignored. While collecting a profile, functions
+   * from all security contexts are included in it. The token-based
+   * filtering is only performed when querying for a profile.
+   *
+   * |record_samples| parameter controls whether individual samples should
+   * be recorded in addition to the aggregated tree.
+   */
+  void StartProfiling(Local<String> title, bool record_samples = false);
+
+  /**
+   * Stops collecting CPU profile with a given title and returns it.
+   * If the title given is empty, finishes the last profile started.
+   */
+  CpuProfile* StopProfiling(Local<String> title);
+
+  /**
+   * Force collection of a sample. Must be called on the VM thread.
+   * Recording the forced sample does not contribute to the aggregated
+   * profile statistics.
+   */
+  void CollectSample();
+
+  /**
+   * Tells the profiler whether the embedder is idle.
+   */
+  void SetIdle(bool is_idle);
+
+ private:
+  CpuProfiler();
+  ~CpuProfiler();
+  CpuProfiler(const CpuProfiler&);
+  CpuProfiler& operator=(const CpuProfiler&);
+};
+
+
+/**
+ * HeapSnapshotEdge represents a directed connection between heap
+ * graph nodes: from retainers to retained nodes.
+ */
+class V8_EXPORT HeapGraphEdge {
+ public:
+  enum Type {
+    kContextVariable = 0,  // A variable from a function context.
+    kElement = 1,          // An element of an array.
+    kProperty = 2,         // A named object property.
+    kInternal = 3,         // A link that can't be accessed from JS,
+                           // thus, its name isn't a real property name
+                           // (e.g. parts of a ConsString).
+    kHidden = 4,           // A link that is needed for proper sizes
+                           // calculation, but may be hidden from user.
+    kShortcut = 5,         // A link that must not be followed during
+                           // sizes calculation.
+    kWeak = 6              // A weak reference (ignored by the GC).
+  };
+
+  /** Returns edge type (see HeapGraphEdge::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns edge name. This can be a variable name, an element index, or
+   * a property name.
+   */
+  Local<Value> GetName() const;
+
+  /** Returns origin node. */
+  const HeapGraphNode* GetFromNode() const;
+
+  /** Returns destination node. */
+  const HeapGraphNode* GetToNode() const;
+};
+
+
+/**
+ * HeapGraphNode represents a node in a heap graph.
+ */
+class V8_EXPORT HeapGraphNode {
+ public:
+  enum Type {
+    kHidden = 0,         // Hidden node, may be filtered when shown to user.
+    kArray = 1,          // An array of elements.
+    kString = 2,         // A string.
+    kObject = 3,         // A JS object (except for arrays and strings).
+    kCode = 4,           // Compiled code.
+    kClosure = 5,        // Function closure.
+    kRegExp = 6,         // RegExp.
+    kHeapNumber = 7,     // Number stored in the heap.
+    kNative = 8,         // Native object (not from V8 heap).
+    kSynthetic = 9,      // Synthetic object, usualy used for grouping
+                         // snapshot items together.
+    kConsString = 10,    // Concatenated string. A pair of pointers to strings.
+    kSlicedString = 11,  // Sliced string. A fragment of another string.
+    kSymbol = 12         // A Symbol (ES6).
+  };
+
+  /** Returns node type (see HeapGraphNode::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns node name. Depending on node's type this can be the name
+   * of the constructor (for objects), the name of the function (for
+   * closures), string value, or an empty string (for compiled code).
+   */
+  Local<String> GetName() const;
+
+  /**
+   * Returns node id. For the same heap object, the id remains the same
+   * across all snapshots.
+   */
+  SnapshotObjectId GetId() const;
+
+  /** Returns node's own size, in bytes. */
+  size_t GetShallowSize() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child by index. */
+  const HeapGraphEdge* GetChild(int index) const;
+};
+
+
+/**
+ * An interface for exporting data from V8, using "push" model.
+ */
+class V8_EXPORT OutputStream {  // NOLINT
+ public:
+  enum WriteResult {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~OutputStream() {}
+  /** Notify about the end of stream. */
+  virtual void EndOfStream() = 0;
+  /** Get preferred output chunk size. Called only once. */
+  virtual int GetChunkSize() { return 1024; }
+  /**
+   * Writes the next chunk of snapshot data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteAsciiChunk(char* data, int size) = 0;
+  /**
+   * Writes the next chunk of heap stats data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate* data, int count) {
+    return kAbort;
+  }
+};
+
+
+/**
+ * HeapSnapshots record the state of the JS heap at some moment.
+ */
+class V8_EXPORT HeapSnapshot {
+ public:
+  enum SerializationFormat {
+    kJSON = 0  // See format description near 'Serialize' method.
+  };
+
+  /** Returns the root node of the heap graph. */
+  const HeapGraphNode* GetRoot() const;
+
+  /** Returns a node by its id. */
+  const HeapGraphNode* GetNodeById(SnapshotObjectId id) const;
+
+  /** Returns total nodes count in the snapshot. */
+  int GetNodesCount() const;
+
+  /** Returns a node by index. */
+  const HeapGraphNode* GetNode(int index) const;
+
+  /** Returns a max seen JS object Id. */
+  SnapshotObjectId GetMaxSnapshotJSObjectId() const;
+
+  /**
+   * Deletes the snapshot and removes it from HeapProfiler's list.
+   * All pointers to nodes, edges and paths previously returned become
+   * invalid.
+   */
+  void Delete();
+
+  /**
+   * Prepare a serialized representation of the snapshot. The result
+   * is written into the stream provided in chunks of specified size.
+   * The total length of the serialized snapshot is unknown in
+   * advance, it can be roughly equal to JS heap size (that means,
+   * it can be really big - tens of megabytes).
+   *
+   * For the JSON format, heap contents are represented as an object
+   * with the following structure:
+   *
+   *  {
+   *    snapshot: {
+   *      title: "...",
+   *      uid: nnn,
+   *      meta: { meta-info },
+   *      node_count: nnn,
+   *      edge_count: nnn
+   *    },
+   *    nodes: [nodes array],
+   *    edges: [edges array],
+   *    strings: [strings array]
+   *  }
+   *
+   * Nodes reference strings, other nodes, and edges by their indexes
+   * in corresponding arrays.
+   */
+  void Serialize(OutputStream* stream,
+                 SerializationFormat format = kJSON) const;
+};
+
+
+/**
+ * An interface for reporting progress and controlling long-running
+ * activities.
+ */
+class V8_EXPORT ActivityControl {  // NOLINT
+ public:
+  enum ControlOption {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~ActivityControl() {}
+  /**
+   * Notify about current progress. The activity can be stopped by
+   * returning kAbort as the callback result.
+   */
+  virtual ControlOption ReportProgressValue(int done, int total) = 0;
+};
+
+
+/**
+ * AllocationProfile is a sampled profile of allocations done by the program.
+ * This is structured as a call-graph.
+ */
+class V8_EXPORT AllocationProfile {
+ public:
+  struct Allocation {
+    /**
+     * Size of the sampled allocation object.
+     */
+    size_t size;
+
+    /**
+     * The number of objects of such size that were sampled.
+     */
+    unsigned int count;
+  };
+
+  /**
+   * Represents a node in the call-graph.
+   */
+  struct Node {
+    /**
+     * Name of the function. May be empty for anonymous functions or if the
+     * script corresponding to this function has been unloaded.
+     */
+    Local<String> name;
+
+    /**
+     * Name of the script containing the function. May be empty if the script
+     * name is not available, or if the script has been unloaded.
+     */
+    Local<String> script_name;
+
+    /**
+     * id of the script where the function is located. May be equal to
+     * v8::UnboundScript::kNoScriptId in cases where the script doesn't exist.
+     */
+    int script_id;
+
+    /**
+     * Start position of the function in the script.
+     */
+    int start_position;
+
+    /**
+     * 1-indexed line number where the function starts. May be
+     * kNoLineNumberInfo if no line number information is available.
+     */
+    int line_number;
+
+    /**
+     * 1-indexed column number where the function starts. May be
+     * kNoColumnNumberInfo if no line number information is available.
+     */
+    int column_number;
+
+    /**
+     * List of callees called from this node for which we have sampled
+     * allocations. The lifetime of the children is scoped to the containing
+     * AllocationProfile.
+     */
+    std::vector<Node*> children;
+
+    /**
+     * List of self allocations done by this node in the call-graph.
+     */
+    std::vector<Allocation> allocations;
+  };
+
+  /**
+   * Returns the root node of the call-graph. The root node corresponds to an
+   * empty JS call-stack. The lifetime of the returned Node* is scoped to the
+   * containing AllocationProfile.
+   */
+  virtual Node* GetRootNode() = 0;
+
+  virtual ~AllocationProfile() {}
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * Interface for controlling heap profiling. Instance of the
+ * profiler can be retrieved using v8::Isolate::GetHeapProfiler.
+ */
+class V8_EXPORT HeapProfiler {
+ public:
+  enum SamplingFlags {
+    kSamplingNoFlags = 0,
+    kSamplingForceGC = 1 << 0,
+  };
+
+  typedef std::unordered_set<const v8::PersistentBase<v8::Value>*>
+      RetainerChildren;
+  typedef std::vector<std::pair<v8::RetainedObjectInfo*, RetainerChildren>>
+      RetainerGroups;
+  typedef std::vector<std::pair<const v8::PersistentBase<v8::Value>*,
+                                const v8::PersistentBase<v8::Value>*>>
+      RetainerEdges;
+
+  struct RetainerInfos {
+    RetainerGroups groups;
+    RetainerEdges edges;
+  };
+
+  /**
+   * Callback function invoked to retrieve all RetainerInfos from the embedder.
+   */
+  typedef RetainerInfos (*GetRetainerInfosCallback)(v8::Isolate* isolate);
+
+  /**
+   * Callback function invoked for obtaining RetainedObjectInfo for
+   * the given JavaScript wrapper object. It is prohibited to enter V8
+   * while the callback is running: only getters on the handle and
+   * GetPointerFromInternalField on the objects are allowed.
+   */
+  typedef RetainedObjectInfo* (*WrapperInfoCallback)(uint16_t class_id,
+                                                     Local<Value> wrapper);
+
+  /** Returns the number of snapshots taken. */
+  int GetSnapshotCount();
+
+  /** Returns a snapshot by index. */
+  const HeapSnapshot* GetHeapSnapshot(int index);
+
+  /**
+   * Returns SnapshotObjectId for a heap object referenced by |value| if
+   * it has been seen by the heap profiler, kUnknownObjectId otherwise.
+   */
+  SnapshotObjectId GetObjectId(Local<Value> value);
+
+  /**
+   * Returns heap object with given SnapshotObjectId if the object is alive,
+   * otherwise empty handle is returned.
+   */
+  Local<Value> FindObjectById(SnapshotObjectId id);
+
+  /**
+   * Clears internal map from SnapshotObjectId to heap object. The new objects
+   * will not be added into it unless a heap snapshot is taken or heap object
+   * tracking is kicked off.
+   */
+  void ClearObjectIds();
+
+  /**
+   * A constant for invalid SnapshotObjectId. GetSnapshotObjectId will return
+   * it in case heap profiler cannot find id  for the object passed as
+   * parameter. HeapSnapshot::GetNodeById will always return NULL for such id.
+   */
+  static const SnapshotObjectId kUnknownObjectId = 0;
+
+  /**
+   * Callback interface for retrieving user friendly names of global objects.
+   */
+  class ObjectNameResolver {
+   public:
+    /**
+     * Returns name to be used in the heap snapshot for given node. Returned
+     * string must stay alive until snapshot collection is completed.
+     */
+    virtual const char* GetName(Local<Object> object) = 0;
+
+   protected:
+    virtual ~ObjectNameResolver() {}
+  };
+
+  /**
+   * Takes a heap snapshot and returns it.
+   */
+  const HeapSnapshot* TakeHeapSnapshot(
+      ActivityControl* control = NULL,
+      ObjectNameResolver* global_object_name_resolver = NULL);
+
+  /**
+   * Starts tracking of heap objects population statistics. After calling
+   * this method, all heap objects relocations done by the garbage collector
+   * are being registered.
+   *
+   * |track_allocations| parameter controls whether stack trace of each
+   * allocation in the heap will be recorded and reported as part of
+   * HeapSnapshot.
+   */
+  void StartTrackingHeapObjects(bool track_allocations = false);
+
+  /**
+   * Adds a new time interval entry to the aggregated statistics array. The
+   * time interval entry contains information on the current heap objects
+   * population size. The method also updates aggregated statistics and
+   * reports updates for all previous time intervals via the OutputStream
+   * object. Updates on each time interval are provided as a stream of the
+   * HeapStatsUpdate structure instances.
+   * If |timestamp_us| is supplied, timestamp of the new entry will be written
+   * into it. The return value of the function is the last seen heap object Id.
+   *
+   * StartTrackingHeapObjects must be called before the first call to this
+   * method.
+   */
+  SnapshotObjectId GetHeapStats(OutputStream* stream,
+                                int64_t* timestamp_us = NULL);
+
+  /**
+   * Stops tracking of heap objects population statistics, cleans up all
+   * collected data. StartHeapObjectsTracking must be called again prior to
+   * calling GetHeapStats next time.
+   */
+  void StopTrackingHeapObjects();
+
+  /**
+   * Starts gathering a sampling heap profile. A sampling heap profile is
+   * similar to tcmalloc's heap profiler and Go's mprof. It samples object
+   * allocations and builds an online 'sampling' heap profile. At any point in
+   * time, this profile is expected to be a representative sample of objects
+   * currently live in the system. Each sampled allocation includes the stack
+   * trace at the time of allocation, which makes this really useful for memory
+   * leak detection.
+   *
+   * This mechanism is intended to be cheap enough that it can be used in
+   * production with minimal performance overhead.
+   *
+   * Allocations are sampled using a randomized Poisson process. On average, one
+   * allocation will be sampled every |sample_interval| bytes allocated. The
+   * |stack_depth| parameter controls the maximum number of stack frames to be
+   * captured on each allocation.
+   *
+   * NOTE: This is a proof-of-concept at this point. Right now we only sample
+   * newspace allocations. Support for paged space allocation (e.g. pre-tenured
+   * objects, large objects, code objects, etc.) and native allocations
+   * doesn't exist yet, but is anticipated in the future.
+   *
+   * Objects allocated before the sampling is started will not be included in
+   * the profile.
+   *
+   * Returns false if a sampling heap profiler is already running.
+   */
+  bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024,
+                                 int stack_depth = 16,
+                                 SamplingFlags flags = kSamplingNoFlags);
+
+  /**
+   * Stops the sampling heap profile and discards the current profile.
+   */
+  void StopSamplingHeapProfiler();
+
+  /**
+   * Returns the sampled profile of allocations allocated (and still live) since
+   * StartSamplingHeapProfiler was called. The ownership of the pointer is
+   * transfered to the caller. Returns nullptr if sampling heap profiler is not
+   * active.
+   */
+  AllocationProfile* GetAllocationProfile();
+
+  /**
+   * Deletes all snapshots taken. All previously returned pointers to
+   * snapshots and their contents become invalid after this call.
+   */
+  void DeleteAllHeapSnapshots();
+
+  /** Binds a callback to embedder's class ID. */
+  void SetWrapperClassInfoProvider(
+      uint16_t class_id,
+      WrapperInfoCallback callback);
+
+  void SetGetRetainerInfosCallback(GetRetainerInfosCallback callback);
+
+  /**
+   * Default value of persistent handle class ID. Must not be used to
+   * define a class. Can be used to reset a class of a persistent
+   * handle.
+   */
+  static const uint16_t kPersistentHandleNoClassId = 0;
+
+  /** Returns memory used for profiler internal data and snapshots. */
+  size_t GetProfilerMemorySize();
+
+ private:
+  HeapProfiler();
+  ~HeapProfiler();
+  HeapProfiler(const HeapProfiler&);
+  HeapProfiler& operator=(const HeapProfiler&);
+};
+
+/**
+ * Interface for providing information about embedder's objects
+ * held by global handles. This information is reported in two ways:
+ *
+ *  1. When calling AddObjectGroup, an embedder may pass
+ *     RetainedObjectInfo instance describing the group.  To collect
+ *     this information while taking a heap snapshot, V8 calls GC
+ *     prologue and epilogue callbacks.
+ *
+ *  2. When a heap snapshot is collected, V8 additionally
+ *     requests RetainedObjectInfos for persistent handles that
+ *     were not previously reported via AddObjectGroup.
+ *
+ * Thus, if an embedder wants to provide information about native
+ * objects for heap snapshots, it can do it in a GC prologue
+ * handler, and / or by assigning wrapper class ids in the following way:
+ *
+ *  1. Bind a callback to class id by calling SetWrapperClassInfoProvider.
+ *  2. Call SetWrapperClassId on certain persistent handles.
+ *
+ * V8 takes ownership of RetainedObjectInfo instances passed to it and
+ * keeps them alive only during snapshot collection. Afterwards, they
+ * are freed by calling the Dispose class function.
+ */
+class V8_EXPORT RetainedObjectInfo {  // NOLINT
+ public:
+  /** Called by V8 when it no longer needs an instance. */
+  virtual void Dispose() = 0;
+
+  /** Returns whether two instances are equivalent. */
+  virtual bool IsEquivalent(RetainedObjectInfo* other) = 0;
+
+  /**
+   * Returns hash value for the instance. Equivalent instances
+   * must have the same hash value.
+   */
+  virtual intptr_t GetHash() = 0;
+
+  /**
+   * Returns human-readable label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetLabel.
+   */
+  virtual const char* GetLabel() = 0;
+
+  /**
+   * Returns human-readable group label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetGroupLabel.
+   * Heap snapshot generator will collect all the group names, create
+   * top level entries with these names and attach the objects to the
+   * corresponding top level group objects. There is a default
+   * implementation which is required because embedders don't have their
+   * own implementation yet.
+   */
+  virtual const char* GetGroupLabel() { return GetLabel(); }
+
+  /**
+   * Returns element count in case if a global handle retains
+   * a subgraph by holding one of its nodes.
+   */
+  virtual intptr_t GetElementCount() { return -1; }
+
+  /** Returns embedder's object size in bytes. */
+  virtual intptr_t GetSizeInBytes() { return -1; }
+
+ protected:
+  RetainedObjectInfo() {}
+  virtual ~RetainedObjectInfo() {}
+
+ private:
+  RetainedObjectInfo(const RetainedObjectInfo&);
+  RetainedObjectInfo& operator=(const RetainedObjectInfo&);
+};
+
+
+/**
+ * A struct for exporting HeapStats data from V8, using "push" model.
+ * See HeapProfiler::GetHeapStats.
+ */
+struct HeapStatsUpdate {
+  HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size)
+    : index(index), count(count), size(size) { }
+  uint32_t index;  // Index of the time interval that was changed.
+  uint32_t count;  // New value of count field for the interval with this index.
+  uint32_t size;  // New value of size field for the interval with this index.
+};
+
+
+}  // namespace v8
+
+
+#endif  // V8_V8_PROFILER_H_
diff --git a/android/armeabi/include/v8/v8-testing.h b/android/armeabi/include/v8/v8-testing.h
new file mode 100644
index 00000000..f67bf253
--- /dev/null
+++ b/android/armeabi/include/v8/v8-testing.h
@@ -0,0 +1,48 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_TEST_H_
+#define V8_V8_TEST_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Testing support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class V8_EXPORT Testing {
+ public:
+  enum StressType {
+    kStressTypeOpt,
+    kStressTypeDeopt
+  };
+
+  /**
+   * Set the type of stressing to do. The default if not set is kStressTypeOpt.
+   */
+  static void SetStressRunType(StressType type);
+
+  /**
+   * Get the number of runs of a given test that is required to get the full
+   * stress coverage.
+   */
+  static int GetStressRuns();
+
+  /**
+   * Indicate the number of the run which is about to start. The value of run
+   * should be between 0 and one less than the result from GetStressRuns()
+   */
+  static void PrepareStressRun(int run);
+
+  /**
+   * Force deoptimization of all functions.
+   */
+  static void DeoptimizeAll(Isolate* isolate);
+};
+
+
+}  // namespace v8
+
+#endif  // V8_V8_TEST_H_
diff --git a/android/armeabi/include/v8/v8-util.h b/android/armeabi/include/v8/v8-util.h
new file mode 100644
index 00000000..a04a5e84
--- /dev/null
+++ b/android/armeabi/include/v8/v8-util.h
@@ -0,0 +1,655 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_UTIL_H_
+#define V8_UTIL_H_
+
+#include "v8.h"  // NOLINT(build/include)
+#include <assert.h>
+#include <map>
+#include <vector>
+
+/**
+ * Support for Persistent containers.
+ *
+ * C++11 embedders can use STL containers with Global values,
+ * but pre-C++11 does not support the required move semantic and hence
+ * may want these container classes.
+ */
+namespace v8 {
+
+typedef uintptr_t PersistentContainerValue;
+static const uintptr_t kPersistentContainerNotFound = 0;
+enum PersistentContainerCallbackType {
+  kNotWeak,
+  // These correspond to v8::WeakCallbackType
+  kWeakWithParameter,
+  kWeakWithInternalFields,
+  kWeak = kWeakWithParameter  // For backwards compatibility.  Deprecate.
+};
+
+
+/**
+ * A default trait implemenation for PersistentValueMap which uses std::map
+ * as a backing map.
+ *
+ * Users will have to implement their own weak callbacks & dispose traits.
+ */
+template<typename K, typename V>
+class StdMapTraits {
+ public:
+  // STL map & related:
+  typedef std::map<K, PersistentContainerValue> Impl;
+  typedef typename Impl::iterator Iterator;
+
+  static bool Empty(Impl* impl) { return impl->empty(); }
+  static size_t Size(Impl* impl) { return impl->size(); }
+  static void Swap(Impl& a, Impl& b) { std::swap(a, b); }  // NOLINT
+  static Iterator Begin(Impl* impl) { return impl->begin(); }
+  static Iterator End(Impl* impl) { return impl->end(); }
+  static K Key(Iterator it) { return it->first; }
+  static PersistentContainerValue Value(Iterator it) { return it->second; }
+  static PersistentContainerValue Set(Impl* impl, K key,
+      PersistentContainerValue value) {
+    std::pair<Iterator, bool> res = impl->insert(std::make_pair(key, value));
+    PersistentContainerValue old_value = kPersistentContainerNotFound;
+    if (!res.second) {
+      old_value = res.first->second;
+      res.first->second = value;
+    }
+    return old_value;
+  }
+  static PersistentContainerValue Get(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    return it->second;
+  }
+  static PersistentContainerValue Remove(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    PersistentContainerValue value = it->second;
+    impl->erase(it);
+    return value;
+  }
+};
+
+
+/**
+ * A default trait implementation for PersistentValueMap, which inherits
+ * a std:map backing map from StdMapTraits and holds non-weak persistent
+ * objects and has no special Dispose handling.
+ *
+ * You should not derive from this class, since MapType depends on the
+ * surrounding class, and hence a subclass cannot simply inherit the methods.
+ */
+template<typename K, typename V>
+class DefaultPersistentValueMapTraits : public StdMapTraits<K, V> {
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef PersistentValueMap<K, V, DefaultPersistentValueMapTraits<K, V> >
+      MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(
+      MapType* map, const K& key, Local<V> value) {
+    return NULL;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return NULL;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) { }
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+};
+
+
+template <typename K, typename V>
+class DefaultGlobalMapTraits : public StdMapTraits<K, V> {
+ private:
+  template <typename T>
+  struct RemovePointer;
+
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef GlobalValueMap<K, V, DefaultGlobalMapTraits<K, V> > MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(MapType* map, const K& key,
+                                                     Local<V> value) {
+    return nullptr;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return nullptr;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) {}
+  static void OnWeakCallback(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+  // This is a second pass callback, so SetSecondPassCallback cannot be called.
+  static void DisposeWeak(const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+
+ private:
+  template <typename T>
+  struct RemovePointer<T*> {
+    typedef T Type;
+  };
+};
+
+
+/**
+ * A map wrapper that allows using Global as a mapped value.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * The map relies on a backing map, whose type and accessors are described
+ * by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template <typename K, typename V, typename Traits>
+class PersistentValueMapBase {
+ public:
+  Isolate* GetIsolate() { return isolate_; }
+
+  /**
+   * Return size of the map.
+   */
+  size_t Size() { return Traits::Size(&impl_); }
+
+  /**
+   * Return whether the map holds weak persistents.
+   */
+  bool IsWeak() { return Traits::kCallbackType != kNotWeak; }
+
+  /**
+   * Get value stored in map.
+   */
+  Local<V> Get(const K& key) {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, key)));
+  }
+
+  /**
+   * Check whether a value is contained in the map.
+   */
+  bool Contains(const K& key) {
+    return Traits::Get(&impl_, key) != kPersistentContainerNotFound;
+  }
+
+  /**
+   * Get value stored in map and set it in returnValue.
+   * Return true if a value was found.
+   */
+  bool SetReturnValue(const K& key,
+      ReturnValue<Value> returnValue) {
+    return SetReturnValueFromVal(&returnValue, Traits::Get(&impl_, key));
+  }
+
+  /**
+   * Call Isolate::SetReference with the given parent and the map value.
+   */
+  void SetReference(const K& key,
+      const Persistent<Object>& parent) {
+    GetIsolate()->SetReference(
+      reinterpret_cast<internal::Object**>(parent.val_),
+      reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))));
+  }
+
+  /**
+   * Call V8::RegisterExternallyReferencedObject with the map value for given
+   * key.
+   */
+  void RegisterExternallyReferencedObject(K& key) {
+    assert(Contains(key));
+    V8::RegisterExternallyReferencedObject(
+        reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))),
+        reinterpret_cast<internal::Isolate*>(GetIsolate()));
+  }
+
+  /**
+   * Return value for key and remove it from the map.
+   */
+  Global<V> Remove(const K& key) {
+    return Release(Traits::Remove(&impl_, key)).Pass();
+  }
+
+  /**
+  * Traverses the map repeatedly,
+  * in case side effects of disposal cause insertions.
+  **/
+  void Clear() {
+    typedef typename Traits::Iterator It;
+    HandleScope handle_scope(isolate_);
+    // TODO(dcarney): figure out if this swap and loop is necessary.
+    while (!Traits::Empty(&impl_)) {
+      typename Traits::Impl impl;
+      Traits::Swap(impl_, impl);
+      for (It i = Traits::Begin(&impl); i != Traits::End(&impl); ++i) {
+        Traits::Dispose(isolate_, Release(Traits::Value(i)).Pass(),
+                        Traits::Key(i));
+      }
+    }
+  }
+
+  /**
+   * Helper class for GetReference/SetWithReference. Do not use outside
+   * that context.
+   */
+  class PersistentValueReference {
+   public:
+    PersistentValueReference() : value_(kPersistentContainerNotFound) { }
+    PersistentValueReference(const PersistentValueReference& other)
+        : value_(other.value_) { }
+
+    Local<V> NewLocal(Isolate* isolate) const {
+      return Local<V>::New(isolate, FromVal(value_));
+    }
+    bool IsEmpty() const {
+      return value_ == kPersistentContainerNotFound;
+    }
+    template<typename T>
+    bool SetReturnValue(ReturnValue<T> returnValue) {
+      return SetReturnValueFromVal(&returnValue, value_);
+    }
+    void Reset() {
+      value_ = kPersistentContainerNotFound;
+    }
+    void operator=(const PersistentValueReference& other) {
+      value_ = other.value_;
+    }
+
+   private:
+    friend class PersistentValueMapBase;
+    friend class PersistentValueMap<K, V, Traits>;
+    friend class GlobalValueMap<K, V, Traits>;
+
+    explicit PersistentValueReference(PersistentContainerValue value)
+        : value_(value) { }
+
+    void operator=(PersistentContainerValue value) {
+      value_ = value;
+    }
+
+    PersistentContainerValue value_;
+  };
+
+  /**
+   * Get a reference to a map value. This enables fast, repeated access
+   * to a value stored in the map while the map remains unchanged.
+   *
+   * Careful: This is potentially unsafe, so please use with care.
+   * The value will become invalid if the value for this key changes
+   * in the underlying map, as a result of Set or Remove for the same
+   * key; as a result of the weak callback for the same key; or as a
+   * result of calling Clear() or destruction of the map.
+   */
+  PersistentValueReference GetReference(const K& key) {
+    return PersistentValueReference(Traits::Get(&impl_, key));
+  }
+
+ protected:
+  explicit PersistentValueMapBase(Isolate* isolate) : isolate_(isolate) {}
+
+  ~PersistentValueMapBase() { Clear(); }
+
+  Isolate* isolate() { return isolate_; }
+  typename Traits::Impl* impl() { return &impl_; }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static PersistentContainerValue Leak(Global<V>* persistent) {
+    return reinterpret_cast<PersistentContainerValue>(persistent->val_);
+  }
+
+  /**
+   * Return a container value as Global and make sure the weak
+   * callback is properly disposed of. All remove functionality should go
+   * through this.
+   */
+  static Global<V> Release(PersistentContainerValue v) {
+    Global<V> p;
+    p.val_ = FromVal(v);
+    if (Traits::kCallbackType != kNotWeak && p.IsWeak()) {
+      Traits::DisposeCallbackData(
+          p.template ClearWeak<typename Traits::WeakCallbackDataType>());
+    }
+    return p.Pass();
+  }
+
+  void RemoveWeak(const K& key) {
+    Global<V> p;
+    p.val_ = FromVal(Traits::Remove(&impl_, key));
+    p.Reset();
+  }
+
+ private:
+  PersistentValueMapBase(PersistentValueMapBase&);
+  void operator=(PersistentValueMapBase&);
+
+  static bool SetReturnValueFromVal(ReturnValue<Value>* returnValue,
+                                    PersistentContainerValue value) {
+    bool hasValue = value != kPersistentContainerNotFound;
+    if (hasValue) {
+      returnValue->SetInternal(
+          *reinterpret_cast<internal::Object**>(FromVal(value)));
+    }
+    return hasValue;
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+
+template <typename K, typename V, typename Traits>
+class PersistentValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit PersistentValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+        Traits::WeakCallbackParameter(this, key, value), WeakCallback);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void WeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      PersistentValueMap<K, V, Traits>* persistentValueMap =
+          Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      Traits::Dispose(data.GetIsolate(),
+                      persistentValueMap->Remove(key).Pass(), key);
+      Traits::DisposeCallbackData(data.GetParameter());
+    }
+  }
+};
+
+
+template <typename K, typename V, typename Traits>
+class GlobalValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit GlobalValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      WeakCallbackType callback_type =
+          Traits::kCallbackType == kWeakWithInternalFields
+              ? WeakCallbackType::kInternalFields
+              : WeakCallbackType::kParameter;
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+          Traits::WeakCallbackParameter(this, key, value), OnWeakCallback,
+          callback_type);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void OnWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      auto map = Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      map->RemoveWeak(key);
+      Traits::OnWeakCallback(data);
+      data.SetSecondPassCallback(SecondWeakCallback);
+    }
+  }
+
+  static void SecondWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    Traits::DisposeWeak(data);
+  }
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Persistents are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template<typename K, typename V,
+    typename Traits = DefaultPersistentValueMapTraits<K, V> >
+class StdPersistentValueMap : public PersistentValueMap<K, V, Traits> {
+ public:
+  explicit StdPersistentValueMap(Isolate* isolate)
+      : PersistentValueMap<K, V, Traits>(isolate) {}
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Globals are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template <typename K, typename V,
+          typename Traits = DefaultGlobalMapTraits<K, V> >
+class StdGlobalValueMap : public GlobalValueMap<K, V, Traits> {
+ public:
+  explicit StdGlobalValueMap(Isolate* isolate)
+      : GlobalValueMap<K, V, Traits>(isolate) {}
+};
+
+
+class DefaultPersistentValueVectorTraits {
+ public:
+  typedef std::vector<PersistentContainerValue> Impl;
+
+  static void Append(Impl* impl, PersistentContainerValue value) {
+    impl->push_back(value);
+  }
+  static bool IsEmpty(const Impl* impl) {
+    return impl->empty();
+  }
+  static size_t Size(const Impl* impl) {
+    return impl->size();
+  }
+  static PersistentContainerValue Get(const Impl* impl, size_t i) {
+    return (i < impl->size()) ? impl->at(i) : kPersistentContainerNotFound;
+  }
+  static void ReserveCapacity(Impl* impl, size_t capacity) {
+    impl->reserve(capacity);
+  }
+  static void Clear(Impl* impl) {
+    impl->clear();
+  }
+};
+
+
+/**
+ * A vector wrapper that safely stores Global values.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * This class relies on a backing vector implementation, whose type and methods
+ * are described by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template<typename V, typename Traits = DefaultPersistentValueVectorTraits>
+class PersistentValueVector {
+ public:
+  explicit PersistentValueVector(Isolate* isolate) : isolate_(isolate) { }
+
+  ~PersistentValueVector() {
+    Clear();
+  }
+
+  /**
+   * Append a value to the vector.
+   */
+  void Append(Local<V> value) {
+    Global<V> persistent(isolate_, value);
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Append a persistent's value to the vector.
+   */
+  void Append(Global<V> persistent) {
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Are there any values in the vector?
+   */
+  bool IsEmpty() const {
+    return Traits::IsEmpty(&impl_);
+  }
+
+  /**
+   * How many elements are in the vector?
+   */
+  size_t Size() const {
+    return Traits::Size(&impl_);
+  }
+
+  /**
+   * Retrieve the i-th value in the vector.
+   */
+  Local<V> Get(size_t index) const {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, index)));
+  }
+
+  /**
+   * Remove all elements from the vector.
+   */
+  void Clear() {
+    size_t length = Traits::Size(&impl_);
+    for (size_t i = 0; i < length; i++) {
+      Global<V> p;
+      p.val_ = FromVal(Traits::Get(&impl_, i));
+    }
+    Traits::Clear(&impl_);
+  }
+
+  /**
+   * Reserve capacity in the vector.
+   * (Efficiency gains depend on the backing implementation.)
+   */
+  void ReserveCapacity(size_t capacity) {
+    Traits::ReserveCapacity(&impl_, capacity);
+  }
+
+ private:
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+}  // namespace v8
+
+#endif  // V8_UTIL_H
diff --git a/android/armeabi/include/v8/v8-value-serializer-version.h b/android/armeabi/include/v8/v8-value-serializer-version.h
new file mode 100644
index 00000000..c72911c6
--- /dev/null
+++ b/android/armeabi/include/v8/v8-value-serializer-version.h
@@ -0,0 +1,24 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Compile-time constants.
+ *
+ * This header provides access to information about the value serializer at
+ * compile time, without declaring or defining any symbols that require linking
+ * to V8.
+ */
+
+#ifndef INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+#define INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+
+#include <stdint.h>
+
+namespace v8 {
+
+constexpr uint32_t CurrentValueSerializerFormatVersion() { return 13; }
+
+}  // namespace v8
+
+#endif  // INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
diff --git a/android/armeabi/include/v8/v8-version-string.h b/android/armeabi/include/v8/v8-version-string.h
new file mode 100644
index 00000000..075282de
--- /dev/null
+++ b/android/armeabi/include/v8/v8-version-string.h
@@ -0,0 +1,33 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_VERSION_STRING_H_
+#define V8_VERSION_STRING_H_
+
+#include "v8-version.h"  // NOLINT(build/include)
+
+// This is here rather than v8-version.h to keep that file simple and
+// machine-processable.
+
+#if V8_IS_CANDIDATE_VERSION
+#define V8_CANDIDATE_STRING " (candidate)"
+#else
+#define V8_CANDIDATE_STRING ""
+#endif
+
+#define V8_SX(x) #x
+#define V8_S(x) V8_SX(x)
+
+#if V8_PATCH_LEVEL > 0
+#define V8_VERSION_STRING                                        \
+  V8_S(V8_MAJOR_VERSION)                                         \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) "." V8_S( \
+      V8_PATCH_LEVEL) V8_CANDIDATE_STRING
+#else
+#define V8_VERSION_STRING \
+  V8_S(V8_MAJOR_VERSION)  \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) V8_CANDIDATE_STRING
+#endif
+
+#endif  // V8_VERSION_STRING_H_
diff --git a/android/armeabi/include/v8/v8-version.h b/android/armeabi/include/v8/v8-version.h
new file mode 100644
index 00000000..0889459c
--- /dev/null
+++ b/android/armeabi/include/v8/v8-version.h
@@ -0,0 +1,20 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INCLUDE_VERSION_H_  // V8_VERSION_H_ conflicts with src/version.h
+#define V8_INCLUDE_VERSION_H_
+
+// These macros define the version number for the current version.
+// NOTE these macros are used by some of the tool scripts and the build
+// system so their names cannot be changed without changing the scripts.
+#define V8_MAJOR_VERSION 6
+#define V8_MINOR_VERSION 0
+#define V8_BUILD_NUMBER 286
+#define V8_PATCH_LEVEL 52
+
+// Use 1 for candidates and 0 otherwise.
+// (Boolean macro values are not supported by all preprocessors.)
+#define V8_IS_CANDIDATE_VERSION 0
+
+#endif  // V8_INCLUDE_VERSION_H_
diff --git a/android/armeabi/include/v8/v8.h b/android/armeabi/include/v8/v8.h
new file mode 100644
index 00000000..da3cdfdc
--- /dev/null
+++ b/android/armeabi/include/v8/v8.h
@@ -0,0 +1,10155 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/** \mainpage V8 API Reference Guide
+ *
+ * V8 is Google's open source JavaScript engine.
+ *
+ * This set of documents provides reference material generated from the
+ * V8 header file, include/v8.h.
+ *
+ * For other documentation see http://code.google.com/apis/v8/
+ */
+
+#ifndef INCLUDE_V8_H_
+#define INCLUDE_V8_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "v8-version.h"  // NOLINT(build/include)
+#include "v8config.h"    // NOLINT(build/include)
+
+// We reserve the V8_* prefix for macros defined in V8 public API and
+// assume there are no name conflicts with the embedder's code.
+
+#ifdef V8_OS_WIN
+
+// Setup for Windows DLL export/import. When building the V8 DLL the
+// BUILDING_V8_SHARED needs to be defined. When building a program which uses
+// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
+// static library or building a program which uses the V8 static library neither
+// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
+#ifdef BUILDING_V8_SHARED
+# define V8_EXPORT __declspec(dllexport)
+#elif USING_V8_SHARED
+# define V8_EXPORT __declspec(dllimport)
+#else
+# define V8_EXPORT
+#endif  // BUILDING_V8_SHARED
+
+#else  // V8_OS_WIN
+
+// Setup for Linux shared library export.
+#if V8_HAS_ATTRIBUTE_VISIBILITY
+# ifdef BUILDING_V8_SHARED
+#  define V8_EXPORT __attribute__ ((visibility("default")))
+# else
+#  define V8_EXPORT
+# endif
+#else
+# define V8_EXPORT
+#endif
+
+#endif  // V8_OS_WIN
+
+/**
+ * The v8 JavaScript engine.
+ */
+namespace v8 {
+
+class AccessorSignature;
+class Array;
+class ArrayBuffer;
+class Boolean;
+class BooleanObject;
+class Context;
+class CpuProfiler;
+class Data;
+class Date;
+class External;
+class Function;
+class FunctionTemplate;
+class HeapProfiler;
+class ImplementationUtilities;
+class Int32;
+class Integer;
+class Isolate;
+template <class T>
+class Maybe;
+class Name;
+class Number;
+class NumberObject;
+class Object;
+class ObjectOperationDescriptor;
+class ObjectTemplate;
+class Platform;
+class Primitive;
+class Promise;
+class PropertyDescriptor;
+class Proxy;
+class RawOperationDescriptor;
+class Script;
+class SharedArrayBuffer;
+class Signature;
+class StartupData;
+class StackFrame;
+class StackTrace;
+class String;
+class StringObject;
+class Symbol;
+class SymbolObject;
+class Private;
+class Uint32;
+class Utils;
+class Value;
+class WasmCompiledModule;
+template <class T> class Local;
+template <class T>
+class MaybeLocal;
+template <class T> class Eternal;
+template<class T> class NonCopyablePersistentTraits;
+template<class T> class PersistentBase;
+template <class T, class M = NonCopyablePersistentTraits<T> >
+class Persistent;
+template <class T>
+class Global;
+template<class K, class V, class T> class PersistentValueMap;
+template <class K, class V, class T>
+class PersistentValueMapBase;
+template <class K, class V, class T>
+class GlobalValueMap;
+template<class V, class T> class PersistentValueVector;
+template<class T, class P> class WeakCallbackObject;
+class FunctionTemplate;
+class ObjectTemplate;
+template<typename T> class FunctionCallbackInfo;
+template<typename T> class PropertyCallbackInfo;
+class StackTrace;
+class StackFrame;
+class Isolate;
+class CallHandlerHelper;
+class EscapableHandleScope;
+template<typename T> class ReturnValue;
+
+namespace internal {
+class Arguments;
+class Heap;
+class HeapObject;
+class Isolate;
+class Object;
+struct StreamedSource;
+template<typename T> class CustomArguments;
+class PropertyCallbackArguments;
+class FunctionCallbackArguments;
+class GlobalHandles;
+}  // namespace internal
+
+namespace debug {
+class ConsoleCallArguments;
+}  // namespace debug
+
+// --- Handles ---
+
+#define TYPE_CHECK(T, S)                                       \
+  while (false) {                                              \
+    *(static_cast<T* volatile*>(0)) = static_cast<S*>(0);      \
+  }
+
+/**
+ * An object reference managed by the v8 garbage collector.
+ *
+ * All objects returned from v8 have to be tracked by the garbage
+ * collector so that it knows that the objects are still alive.  Also,
+ * because the garbage collector may move objects, it is unsafe to
+ * point directly to an object.  Instead, all objects are stored in
+ * handles which are known by the garbage collector and updated
+ * whenever an object moves.  Handles should always be passed by value
+ * (except in cases like out-parameters) and they should never be
+ * allocated on the heap.
+ *
+ * There are two types of handles: local and persistent handles.
+ *
+ * Local handles are light-weight and transient and typically used in
+ * local operations.  They are managed by HandleScopes. That means that a
+ * HandleScope must exist on the stack when they are created and that they are
+ * only valid inside of the HandleScope active during their creation.
+ * For passing a local handle to an outer HandleScope, an EscapableHandleScope
+ * and its Escape() method must be used.
+ *
+ * Persistent handles can be used when storing objects across several
+ * independent operations and have to be explicitly deallocated when they're no
+ * longer used.
+ *
+ * It is safe to extract the object stored in the handle by
+ * dereferencing the handle (for instance, to extract the Object* from
+ * a Local<Object>); the value will still be governed by a handle
+ * behind the scenes and the same rules apply to these values as to
+ * their handles.
+ */
+template <class T>
+class Local {
+ public:
+  V8_INLINE Local() : val_(0) {}
+  template <class S>
+  V8_INLINE Local(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    /**
+     * This check fails when trying to convert between incompatible
+     * handles. For example, converting from a Local<String> to a
+     * Local<Number>.
+     */
+    TYPE_CHECK(T, S);
+  }
+
+  /**
+   * Returns true if the handle is empty.
+   */
+  V8_INLINE bool IsEmpty() const { return val_ == 0; }
+
+  /**
+   * Sets the handle to be empty. IsEmpty() will then return true.
+   */
+  V8_INLINE void Clear() { val_ = 0; }
+
+  V8_INLINE T* operator->() const { return val_; }
+
+  V8_INLINE T* operator*() const { return val_; }
+
+  /**
+   * Checks whether two handles are the same.
+   * Returns true if both are empty, or if the objects
+   * to which they refer are identical.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  template <class S> V8_INLINE bool operator==(
+      const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  /**
+   * Checks whether two handles are different.
+   * Returns true if only one of the handles is empty, or if
+   * the objects to which they refer are different.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S> V8_INLINE bool operator!=(
+      const Persistent<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   * Cast a handle to a subclass, e.g. Local<Value> to Local<Object>.
+   * This is only valid if the handle actually refers to a value of the
+   * target type.
+   */
+  template <class S> V8_INLINE static Local<T> Cast(Local<S> that) {
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (that.IsEmpty()) return Local<T>();
+#endif
+    return Local<T>(T::Cast(*that));
+  }
+
+  /**
+   * Calling this is equivalent to Local<S>::Cast().
+   * In particular, this is only valid if the handle actually refers to a value
+   * of the target type.
+   */
+  template <class S>
+  V8_INLINE Local<S> As() const {
+    return Local<S>::Cast(*this);
+  }
+
+  /**
+   * Create a local handle for the content of another handle.
+   * The referee is kept alive by the local handle even when
+   * the original handle is destroyed/disposed.
+   */
+  V8_INLINE static Local<T> New(Isolate* isolate, Local<T> that);
+  V8_INLINE static Local<T> New(Isolate* isolate,
+                                const PersistentBase<T>& that);
+
+ private:
+  friend class Utils;
+  template<class F> friend class Eternal;
+  template<class F> friend class PersistentBase;
+  template<class F, class M> friend class Persistent;
+  template<class F> friend class Local;
+  template <class F>
+  friend class MaybeLocal;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  friend class String;
+  friend class Object;
+  friend class Context;
+  friend class Private;
+  template<class F> friend class internal::CustomArguments;
+  friend Local<Primitive> Undefined(Isolate* isolate);
+  friend Local<Primitive> Null(Isolate* isolate);
+  friend Local<Boolean> True(Isolate* isolate);
+  friend Local<Boolean> False(Isolate* isolate);
+  friend class HandleScope;
+  friend class EscapableHandleScope;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  template <class F>
+  friend class ReturnValue;
+
+  explicit V8_INLINE Local(T* that) : val_(that) {}
+  V8_INLINE static Local<T> New(Isolate* isolate, T* that);
+  T* val_;
+};
+
+
+#if !defined(V8_IMMINENT_DEPRECATION_WARNINGS)
+// Handle is an alias for Local for historical reasons.
+template <class T>
+using Handle = Local<T>;
+#endif
+
+
+/**
+ * A MaybeLocal<> is a wrapper around Local<> that enforces a check whether
+ * the Local<> is empty before it can be used.
+ *
+ * If an API method returns a MaybeLocal<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, an
+ * empty MaybeLocal is returned.
+ */
+template <class T>
+class MaybeLocal {
+ public:
+  V8_INLINE MaybeLocal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE MaybeLocal(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    TYPE_CHECK(T, S);
+  }
+
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * |false| is returned and |out| is left untouched.
+   */
+  template <class S>
+  V8_WARN_UNUSED_RESULT V8_INLINE bool ToLocal(Local<S>* out) const {
+    out->val_ = IsEmpty() ? nullptr : this->val_;
+    return !IsEmpty();
+  }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * V8 will crash the process.
+   */
+  V8_INLINE Local<T> ToLocalChecked();
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>, using a default value if this
+   * MaybeLocal<> is empty.
+   */
+  template <class S>
+  V8_INLINE Local<S> FromMaybe(Local<S> default_value) const {
+    return IsEmpty() ? default_value : Local<S>(val_);
+  }
+
+ private:
+  T* val_;
+};
+
+/**
+ * Eternal handles are set-once handles that live for the lifetime of the
+ * isolate.
+ */
+template <class T> class Eternal {
+ public:
+  V8_INLINE Eternal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE Eternal(Isolate* isolate, Local<S> handle) : val_(nullptr) {
+    Set(isolate, handle);
+  }
+  // Can only be safely called if already set.
+  V8_INLINE Local<T> Get(Isolate* isolate) const;
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+  template<class S> V8_INLINE void Set(Isolate* isolate, Local<S> handle);
+
+ private:
+  T* val_;
+};
+
+
+static const int kInternalFieldsInWeakCallback = 2;
+static const int kEmbedderFieldsInWeakCallback = 2;
+
+template <typename T>
+class WeakCallbackInfo {
+ public:
+  typedef void (*Callback)(const WeakCallbackInfo<T>& data);
+
+  WeakCallbackInfo(Isolate* isolate, T* parameter,
+                   void* embedder_fields[kEmbedderFieldsInWeakCallback],
+                   Callback* callback)
+      : isolate_(isolate), parameter_(parameter), callback_(callback) {
+    for (int i = 0; i < kEmbedderFieldsInWeakCallback; ++i) {
+      embedder_fields_[i] = embedder_fields[i];
+    }
+  }
+
+  V8_INLINE Isolate* GetIsolate() const { return isolate_; }
+  V8_INLINE T* GetParameter() const { return parameter_; }
+  V8_INLINE void* GetInternalField(int index) const;
+
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField1() const) {
+    return embedder_fields_[0];
+  }
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField2() const) {
+    return embedder_fields_[1];
+  }
+
+  V8_DEPRECATED("Not realiable once SetSecondPassCallback() was used.",
+                bool IsFirstPass() const) {
+    return callback_ != nullptr;
+  }
+
+  // When first called, the embedder MUST Reset() the Global which triggered the
+  // callback. The Global itself is unusable for anything else. No v8 other api
+  // calls may be called in the first callback. Should additional work be
+  // required, the embedder must set a second pass callback, which will be
+  // called after all the initial callbacks are processed.
+  // Calling SetSecondPassCallback on the second pass will immediately crash.
+  void SetSecondPassCallback(Callback callback) const { *callback_ = callback; }
+
+ private:
+  Isolate* isolate_;
+  T* parameter_;
+  Callback* callback_;
+  void* embedder_fields_[kEmbedderFieldsInWeakCallback];
+};
+
+
+// kParameter will pass a void* parameter back to the callback, kInternalFields
+// will pass the first two internal fields back to the callback, kFinalizer
+// will pass a void* parameter back, but is invoked before the object is
+// actually collected, so it can be resurrected. In the last case, it is not
+// possible to request a second pass callback.
+enum class WeakCallbackType { kParameter, kInternalFields, kFinalizer };
+
+/**
+ * An object reference that is independent of any handle scope.  Where
+ * a Local handle only lives as long as the HandleScope in which it was
+ * allocated, a PersistentBase handle remains valid until it is explicitly
+ * disposed using Reset().
+ *
+ * A persistent handle contains a reference to a storage cell within
+ * the V8 engine which holds an object value and which is updated by
+ * the garbage collector whenever the object is moved.  A new storage
+ * cell can be created using the constructor or PersistentBase::Reset and
+ * existing handles can be disposed using PersistentBase::Reset.
+ *
+ */
+template <class T> class PersistentBase {
+ public:
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * IsEmpty() will return true after this call.
+   */
+  V8_INLINE void Reset();
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const Local<S>& other);
+
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const PersistentBase<S>& other);
+
+  V8_INLINE bool IsEmpty() const { return val_ == NULL; }
+  V8_INLINE void Empty() { val_ = 0; }
+
+  V8_INLINE Local<T> Get(Isolate* isolate) const {
+    return Local<T>::New(isolate, *this);
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const PersistentBase<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   *  Install a finalization callback on this object.
+   *  NOTE: There is no guarantee as to *when* or even *if* the callback is
+   *  invoked. The invocation is performed solely on a best effort basis.
+   *  As always, GC-based finalization should *not* be relied upon for any
+   *  critical form of resource management!
+   */
+  template <typename P>
+  V8_INLINE void SetWeak(P* parameter,
+                         typename WeakCallbackInfo<P>::Callback callback,
+                         WeakCallbackType type);
+
+  /**
+   * Turns this handle into a weak phantom handle without finalization callback.
+   * The handle will be reset automatically when the garbage collector detects
+   * that the object is no longer reachable.
+   * A related function Isolate::NumberOfPhantomHandleResetsSinceLastCall
+   * returns how many phantom handles were reset by the garbage collector.
+   */
+  V8_INLINE void SetWeak();
+
+  template<typename P>
+  V8_INLINE P* ClearWeak();
+
+  // TODO(dcarney): remove this.
+  V8_INLINE void ClearWeak() { ClearWeak<void>(); }
+
+  /**
+   * Allows the embedder to tell the v8 garbage collector that a certain object
+   * is alive. Only allowed when the embedder is asked to trace its heap by
+   * EmbedderHeapTracer.
+   */
+  V8_INLINE void RegisterExternalReference(Isolate* isolate) const;
+
+  /**
+   * Marks the reference to this object independent. Garbage collector is free
+   * to ignore any object groups containing this object. Weak callback for an
+   * independent handle should not assume that it will be preceded by a global
+   * GC prologue callback or followed by a global GC epilogue callback.
+   */
+  V8_INLINE void MarkIndependent();
+
+  /**
+   * Marks the reference to this object as active. The scavenge garbage
+   * collection should not reclaim the objects marked as active.
+   * This bit is cleared after the each garbage collection pass.
+   */
+  V8_INLINE void MarkActive();
+
+  V8_INLINE bool IsIndependent() const;
+
+  /** Checks if the handle holds the only reference to an object. */
+  V8_INLINE bool IsNearDeath() const;
+
+  /** Returns true if the handle's reference is weak.  */
+  V8_INLINE bool IsWeak() const;
+
+  /**
+   * Assigns a wrapper class ID to the handle. See RetainedObjectInfo interface
+   * description in v8-profiler.h for details.
+   */
+  V8_INLINE void SetWrapperClassId(uint16_t class_id);
+
+  /**
+   * Returns the class ID previously assigned to this handle or 0 if no class ID
+   * was previously assigned.
+   */
+  V8_INLINE uint16_t WrapperClassId() const;
+
+  PersistentBase(const PersistentBase& other) = delete;  // NOLINT
+  void operator=(const PersistentBase&) = delete;
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template <class F>
+  friend class Global;
+  template<class F> friend class PersistentBase;
+  template<class F> friend class ReturnValue;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  friend class Object;
+
+  explicit V8_INLINE PersistentBase(T* val) : val_(val) {}
+  V8_INLINE static T* New(Isolate* isolate, T* that);
+
+  T* val_;
+};
+
+
+/**
+ * Default traits for Persistent. This class does not allow
+ * use of the copy constructor or assignment operator.
+ * At present kResetInDestructor is not set, but that will change in a future
+ * version.
+ */
+template<class T>
+class NonCopyablePersistentTraits {
+ public:
+  typedef Persistent<T, NonCopyablePersistentTraits<T> > NonCopyablePersistent;
+  static const bool kResetInDestructor = false;
+  template<class S, class M>
+  V8_INLINE static void Copy(const Persistent<S, M>& source,
+                             NonCopyablePersistent* dest) {
+    Uncompilable<Object>();
+  }
+  // TODO(dcarney): come up with a good compile error here.
+  template<class O> V8_INLINE static void Uncompilable() {
+    TYPE_CHECK(O, Primitive);
+  }
+};
+
+
+/**
+ * Helper class traits to allow copying and assignment of Persistent.
+ * This will clone the contents of storage cell, but not any of the flags, etc.
+ */
+template<class T>
+struct CopyablePersistentTraits {
+  typedef Persistent<T, CopyablePersistentTraits<T> > CopyablePersistent;
+  static const bool kResetInDestructor = true;
+  template<class S, class M>
+  static V8_INLINE void Copy(const Persistent<S, M>& source,
+                             CopyablePersistent* dest) {
+    // do nothing, just allow copy
+  }
+};
+
+
+/**
+ * A PersistentBase which allows copy and assignment.
+ *
+ * Copy, assignment and destructor behavior is controlled by the traits
+ * class M.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T, class M> class Persistent : public PersistentBase<T> {
+ public:
+  /**
+   * A Persistent with no storage cell.
+   */
+  V8_INLINE Persistent() : PersistentBase<T>(0) { }
+  /**
+   * Construct a Persistent from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Persistent(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Persistent from a Persistent.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S, class M2>
+  V8_INLINE Persistent(Isolate* isolate, const Persistent<S, M2>& that)
+    : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * The copy constructors and assignment operator create a Persistent
+   * exactly as the Persistent constructor, but the Copy function from the
+   * traits class is called, allowing the setting of flags based on the
+   * copied Persistent.
+   */
+  V8_INLINE Persistent(const Persistent& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent(const Persistent<S, M2>& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  V8_INLINE Persistent& operator=(const Persistent& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent& operator=(const Persistent<S, M2>& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  /**
+   * The destructor will dispose the Persistent based on the
+   * kResetInDestructor flags in the traits class.  Since not calling dispose
+   * can result in a memory leak, it is recommended to always set this flag.
+   */
+  V8_INLINE ~Persistent() {
+    if (M::kResetInDestructor) this->Reset();
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE static Persistent<T>& Cast(const Persistent<S>& that) {  // NOLINT
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (!that.IsEmpty()) T::Cast(*that);
+#endif
+    return reinterpret_cast<Persistent<T>&>(const_cast<Persistent<S>&>(that));
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE Persistent<S>& As() const {  // NOLINT
+    return Persistent<S>::Cast(*this);
+  }
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template<class F> friend class ReturnValue;
+
+  explicit V8_INLINE Persistent(T* that) : PersistentBase<T>(that) {}
+  V8_INLINE T* operator*() const { return this->val_; }
+  template<class S, class M2>
+  V8_INLINE void Copy(const Persistent<S, M2>& that);
+};
+
+
+/**
+ * A PersistentBase which has move semantics.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T>
+class Global : public PersistentBase<T> {
+ public:
+  /**
+   * A Global with no storage cell.
+   */
+  V8_INLINE Global() : PersistentBase<T>(nullptr) {}
+  /**
+   * Construct a Global from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Global from a PersistentBase.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, const PersistentBase<S>& that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, that.val_)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Move constructor.
+   */
+  V8_INLINE Global(Global&& other) : PersistentBase<T>(other.val_) {  // NOLINT
+    other.val_ = nullptr;
+  }
+  V8_INLINE ~Global() { this->Reset(); }
+  /**
+   * Move via assignment.
+   */
+  template <class S>
+  V8_INLINE Global& operator=(Global<S>&& rhs) {  // NOLINT
+    TYPE_CHECK(T, S);
+    if (this != &rhs) {
+      this->Reset();
+      this->val_ = rhs.val_;
+      rhs.val_ = nullptr;
+    }
+    return *this;
+  }
+  /**
+   * Pass allows returning uniques from functions, etc.
+   */
+  Global Pass() { return static_cast<Global&&>(*this); }  // NOLINT
+
+  /*
+   * For compatibility with Chromium's base::Bind (base::Passed).
+   */
+  typedef void MoveOnlyTypeForCPP03;
+
+  Global(const Global&) = delete;
+  void operator=(const Global&) = delete;
+
+ private:
+  template <class F>
+  friend class ReturnValue;
+  V8_INLINE T* operator*() const { return this->val_; }
+};
+
+
+// UniquePersistent is an alias for Global for historical reason.
+template <class T>
+using UniquePersistent = Global<T>;
+
+
+ /**
+ * A stack-allocated class that governs a number of local handles.
+ * After a handle scope has been created, all local handles will be
+ * allocated within that handle scope until either the handle scope is
+ * deleted or another handle scope is created.  If there is already a
+ * handle scope and a new one is created, all allocations will take
+ * place in the new handle scope until it is deleted.  After that,
+ * new handles will again be allocated in the original handle scope.
+ *
+ * After the handle scope of a local handle has been deleted the
+ * garbage collector will no longer track the object stored in the
+ * handle and may deallocate it.  The behavior of accessing a handle
+ * for which the handle scope has been deleted is undefined.
+ */
+class V8_EXPORT HandleScope {
+ public:
+  explicit HandleScope(Isolate* isolate);
+
+  ~HandleScope();
+
+  /**
+   * Counts the number of allocated handles.
+   */
+  static int NumberOfHandles(Isolate* isolate);
+
+  V8_INLINE Isolate* GetIsolate() const {
+    return reinterpret_cast<Isolate*>(isolate_);
+  }
+
+  HandleScope(const HandleScope&) = delete;
+  void operator=(const HandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ protected:
+  V8_INLINE HandleScope() {}
+
+  void Initialize(Isolate* isolate);
+
+  static internal::Object** CreateHandle(internal::Isolate* isolate,
+                                         internal::Object* value);
+
+ private:
+  // Uses heap_object to obtain the current Isolate.
+  static internal::Object** CreateHandle(internal::HeapObject* heap_object,
+                                         internal::Object* value);
+
+  internal::Isolate* isolate_;
+  internal::Object** prev_next_;
+  internal::Object** prev_limit_;
+
+  // Local::New uses CreateHandle with an Isolate* parameter.
+  template<class F> friend class Local;
+
+  // Object::GetInternalField and Context::GetEmbedderData use CreateHandle with
+  // a HeapObject* in their shortcuts.
+  friend class Object;
+  friend class Context;
+};
+
+
+/**
+ * A HandleScope which first allocates a handle in the current scope
+ * which will be later filled with the escape value.
+ */
+class V8_EXPORT EscapableHandleScope : public HandleScope {
+ public:
+  explicit EscapableHandleScope(Isolate* isolate);
+  V8_INLINE ~EscapableHandleScope() {}
+
+  /**
+   * Pushes the value into the previous scope and returns a handle to it.
+   * Cannot be called twice.
+   */
+  template <class T>
+  V8_INLINE Local<T> Escape(Local<T> value) {
+    internal::Object** slot =
+        Escape(reinterpret_cast<internal::Object**>(*value));
+    return Local<T>(reinterpret_cast<T*>(slot));
+  }
+
+  EscapableHandleScope(const EscapableHandleScope&) = delete;
+  void operator=(const EscapableHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Object** Escape(internal::Object** escape_value);
+  internal::Object** escape_slot_;
+};
+
+/**
+ * A SealHandleScope acts like a handle scope in which no handle allocations
+ * are allowed. It can be useful for debugging handle leaks.
+ * Handles can be allocated within inner normal HandleScopes.
+ */
+class V8_EXPORT SealHandleScope {
+ public:
+  SealHandleScope(Isolate* isolate);
+  ~SealHandleScope();
+
+  SealHandleScope(const SealHandleScope&) = delete;
+  void operator=(const SealHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Isolate* const isolate_;
+  internal::Object** prev_limit_;
+  int prev_sealed_level_;
+};
+
+
+// --- Special objects ---
+
+
+/**
+ * The superclass of values and API object templates.
+ */
+class V8_EXPORT Data {
+ private:
+  Data();
+};
+
+
+/**
+ * The optional attributes of ScriptOrigin.
+ */
+class ScriptOriginOptions {
+ public:
+  V8_INLINE ScriptOriginOptions(bool is_shared_cross_origin = false,
+                                bool is_opaque = false, bool is_wasm = false,
+                                bool is_module = false)
+      : flags_((is_shared_cross_origin ? kIsSharedCrossOrigin : 0) |
+               (is_wasm ? kIsWasm : 0) | (is_opaque ? kIsOpaque : 0) |
+               (is_module ? kIsModule : 0)) {}
+  V8_INLINE ScriptOriginOptions(int flags)
+      : flags_(flags &
+               (kIsSharedCrossOrigin | kIsOpaque | kIsWasm | kIsModule)) {}
+
+  bool IsSharedCrossOrigin() const {
+    return (flags_ & kIsSharedCrossOrigin) != 0;
+  }
+  bool IsOpaque() const { return (flags_ & kIsOpaque) != 0; }
+  bool IsWasm() const { return (flags_ & kIsWasm) != 0; }
+  bool IsModule() const { return (flags_ & kIsModule) != 0; }
+
+  int Flags() const { return flags_; }
+
+ private:
+  enum {
+    kIsSharedCrossOrigin = 1,
+    kIsOpaque = 1 << 1,
+    kIsWasm = 1 << 2,
+    kIsModule = 1 << 3
+  };
+  const int flags_;
+};
+
+/**
+ * The origin, within a file, of a script.
+ */
+class ScriptOrigin {
+ public:
+  V8_INLINE ScriptOrigin(
+      Local<Value> resource_name,
+      Local<Integer> resource_line_offset = Local<Integer>(),
+      Local<Integer> resource_column_offset = Local<Integer>(),
+      Local<Boolean> resource_is_shared_cross_origin = Local<Boolean>(),
+      Local<Integer> script_id = Local<Integer>(),
+      Local<Value> source_map_url = Local<Value>(),
+      Local<Boolean> resource_is_opaque = Local<Boolean>(),
+      Local<Boolean> is_wasm = Local<Boolean>(),
+      Local<Boolean> is_module = Local<Boolean>());
+
+  V8_INLINE Local<Value> ResourceName() const;
+  V8_INLINE Local<Integer> ResourceLineOffset() const;
+  V8_INLINE Local<Integer> ResourceColumnOffset() const;
+  /**
+    * Returns true for embedder's debugger scripts
+    */
+  V8_INLINE Local<Integer> ScriptID() const;
+  V8_INLINE Local<Value> SourceMapUrl() const;
+  V8_INLINE ScriptOriginOptions Options() const { return options_; }
+
+ private:
+  Local<Value> resource_name_;
+  Local<Integer> resource_line_offset_;
+  Local<Integer> resource_column_offset_;
+  ScriptOriginOptions options_;
+  Local<Integer> script_id_;
+  Local<Value> source_map_url_;
+};
+
+
+/**
+ * A compiled JavaScript script, not yet tied to a Context.
+ */
+class V8_EXPORT UnboundScript {
+ public:
+  /**
+   * Binds the script to the currently entered context.
+   */
+  Local<Script> BindToCurrentContext();
+
+  int GetId();
+  Local<Value> GetScriptName();
+
+  /**
+   * Data read from magic sourceURL comments.
+   */
+  Local<Value> GetSourceURL();
+  /**
+   * Data read from magic sourceMappingURL comments.
+   */
+  Local<Value> GetSourceMappingURL();
+
+  /**
+   * Returns zero based line number of the code_pos location in the script.
+   * -1 will be returned if no information available.
+   */
+  int GetLineNumber(int code_pos);
+
+  static const int kNoScriptId = 0;
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT Module {
+ public:
+  /**
+   * Returns the number of modules requested by this module.
+   */
+  int GetModuleRequestsLength() const;
+
+  /**
+   * Returns the ith module specifier in this module.
+   * i must be < GetModuleRequestsLength() and >= 0.
+   */
+  Local<String> GetModuleRequest(int i) const;
+
+  /**
+   * Returns the identity hash for this object.
+   */
+  int GetIdentityHash() const;
+
+  typedef MaybeLocal<Module> (*ResolveCallback)(Local<Context> context,
+                                                Local<String> specifier,
+                                                Local<Module> referrer);
+
+  /**
+   * ModuleDeclarationInstantiation
+   *
+   * Returns false if an exception occurred during instantiation. (In the case
+   * where the callback throws an exception, that exception is propagated.)
+   */
+  V8_WARN_UNUSED_RESULT bool Instantiate(Local<Context> context,
+                                         ResolveCallback callback);
+
+  /**
+   * ModuleEvaluation
+   *
+   * Returns the completion value.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Evaluate(Local<Context> context);
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT DynamicImportResult {
+ public:
+  /**
+   * Resolves the promise with the namespace object of the given
+   * module.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportSuccess(Local<Context> context,
+                                                        Local<Module> module);
+
+  /**
+   * Rejects the promise with the given exception.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportFailure(Local<Context> context,
+                                                        Local<Value> exception);
+};
+
+/**
+ * A compiled JavaScript script, tied to a Context which was active when the
+ * script was compiled.
+ */
+class V8_EXPORT Script {
+ public:
+  /**
+   * A shorthand for ScriptCompiler::Compile().
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Script> Compile(Local<String> source,
+                            ScriptOrigin* origin = nullptr));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Local<String> source,
+      ScriptOrigin* origin = nullptr);
+
+  static Local<Script> V8_DEPRECATE_SOON("Use maybe version",
+                                         Compile(Local<String> source,
+                                                 Local<String> file_name));
+
+  /**
+   * Runs the script returning the resulting value. It will be run in the
+   * context in which it was created (ScriptCompiler::CompileBound or
+   * UnboundScript::BindToCurrentContext()).
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Run());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Run(Local<Context> context);
+
+  /**
+   * Returns the corresponding context-unbound script.
+   */
+  Local<UnboundScript> GetUnboundScript();
+};
+
+
+/**
+ * For compiling scripts.
+ */
+class V8_EXPORT ScriptCompiler {
+ public:
+  /**
+   * Compilation data that the embedder can cache and pass back to speed up
+   * future compilations. The data is produced if the CompilerOptions passed to
+   * the compilation functions in ScriptCompiler contains produce_data_to_cache
+   * = true. The data to cache can then can be retrieved from
+   * UnboundScript.
+   */
+  struct V8_EXPORT CachedData {
+    enum BufferPolicy {
+      BufferNotOwned,
+      BufferOwned
+    };
+
+    CachedData()
+        : data(NULL),
+          length(0),
+          rejected(false),
+          buffer_policy(BufferNotOwned) {}
+
+    // If buffer_policy is BufferNotOwned, the caller keeps the ownership of
+    // data and guarantees that it stays alive until the CachedData object is
+    // destroyed. If the policy is BufferOwned, the given data will be deleted
+    // (with delete[]) when the CachedData object is destroyed.
+    CachedData(const uint8_t* data, int length,
+               BufferPolicy buffer_policy = BufferNotOwned);
+    ~CachedData();
+    // TODO(marja): Async compilation; add constructors which take a callback
+    // which will be called when V8 no longer needs the data.
+    const uint8_t* data;
+    int length;
+    bool rejected;
+    BufferPolicy buffer_policy;
+
+    // Prevent copying.
+    CachedData(const CachedData&) = delete;
+    CachedData& operator=(const CachedData&) = delete;
+  };
+
+  /**
+   * Source code which can be then compiled to a UnboundScript or Script.
+   */
+  class Source {
+   public:
+    // Source takes ownership of CachedData.
+    V8_INLINE Source(Local<String> source_string, const ScriptOrigin& origin,
+           CachedData* cached_data = NULL);
+    V8_INLINE Source(Local<String> source_string,
+                     CachedData* cached_data = NULL);
+    V8_INLINE ~Source();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the Source object is
+    // alive.
+    V8_INLINE const CachedData* GetCachedData() const;
+
+    V8_INLINE const ScriptOriginOptions& GetResourceOptions() const;
+
+    // Prevent copying.
+    Source(const Source&) = delete;
+    Source& operator=(const Source&) = delete;
+
+   private:
+    friend class ScriptCompiler;
+
+    Local<String> source_string;
+
+    // Origin information
+    Local<Value> resource_name;
+    Local<Integer> resource_line_offset;
+    Local<Integer> resource_column_offset;
+    ScriptOriginOptions resource_options;
+    Local<Value> source_map_url;
+
+    // Cached data from previous compilation (if a kConsume*Cache flag is
+    // set), or hold newly generated cache data (kProduce*Cache flags) are
+    // set when calling a compile method.
+    CachedData* cached_data;
+  };
+
+  /**
+   * For streaming incomplete script data to V8. The embedder should implement a
+   * subclass of this class.
+   */
+  class V8_EXPORT ExternalSourceStream {
+   public:
+    virtual ~ExternalSourceStream() {}
+
+    /**
+     * V8 calls this to request the next chunk of data from the embedder. This
+     * function will be called on a background thread, so it's OK to block and
+     * wait for the data, if the embedder doesn't have data yet. Returns the
+     * length of the data returned. When the data ends, GetMoreData should
+     * return 0. Caller takes ownership of the data.
+     *
+     * When streaming UTF-8 data, V8 handles multi-byte characters split between
+     * two data chunks, but doesn't handle multi-byte characters split between
+     * more than two data chunks. The embedder can avoid this problem by always
+     * returning at least 2 bytes of data.
+     *
+     * If the embedder wants to cancel the streaming, they should make the next
+     * GetMoreData call return 0. V8 will interpret it as end of data (and most
+     * probably, parsing will fail). The streaming task will return as soon as
+     * V8 has parsed the data it received so far.
+     */
+    virtual size_t GetMoreData(const uint8_t** src) = 0;
+
+    /**
+     * V8 calls this method to set a 'bookmark' at the current position in
+     * the source stream, for the purpose of (maybe) later calling
+     * ResetToBookmark. If ResetToBookmark is called later, then subsequent
+     * calls to GetMoreData should return the same data as they did when
+     * SetBookmark was called earlier.
+     *
+     * The embedder may return 'false' to indicate it cannot provide this
+     * functionality.
+     */
+    virtual bool SetBookmark();
+
+    /**
+     * V8 calls this to return to a previously set bookmark.
+     */
+    virtual void ResetToBookmark();
+  };
+
+
+  /**
+   * Source code which can be streamed into V8 in pieces. It will be parsed
+   * while streaming. It can be compiled after the streaming is complete.
+   * StreamedSource must be kept alive while the streaming task is ran (see
+   * ScriptStreamingTask below).
+   */
+  class V8_EXPORT StreamedSource {
+   public:
+    enum Encoding { ONE_BYTE, TWO_BYTE, UTF8 };
+
+    StreamedSource(ExternalSourceStream* source_stream, Encoding encoding);
+    ~StreamedSource();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the StreamedSource
+    // object is alive.
+    const CachedData* GetCachedData() const;
+
+    internal::StreamedSource* impl() const { return impl_; }
+
+    // Prevent copying.
+    StreamedSource(const StreamedSource&) = delete;
+    StreamedSource& operator=(const StreamedSource&) = delete;
+
+   private:
+    internal::StreamedSource* impl_;
+  };
+
+  /**
+   * A streaming task which the embedder must run on a background thread to
+   * stream scripts into V8. Returned by ScriptCompiler::StartStreamingScript.
+   */
+  class ScriptStreamingTask {
+   public:
+    virtual ~ScriptStreamingTask() {}
+    virtual void Run() = 0;
+  };
+
+  enum CompileOptions {
+    kNoCompileOptions = 0,
+    kProduceParserCache,
+    kConsumeParserCache,
+    kProduceCodeCache,
+    kConsumeCodeCache
+  };
+
+  /**
+   * Compiles the specified script (context-independent).
+   * Cached data as part of the source object can be optionally produced to be
+   * consumed later to speed up compilation of identical source scripts.
+   *
+   * Note that when producing cached data, the source must point to NULL for
+   * cached data. When consuming cached data, the cached data must have been
+   * produced by the same version of V8.
+   *
+   * \param source Script source code.
+   * \return Compiled script object (context independent; for running it must be
+   *   bound to a context).
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<UnboundScript> CompileUnbound(
+                           Isolate* isolate, Source* source,
+                           CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundScript(
+      Isolate* isolate, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles the specified script (bound to current context).
+   *
+   * \param source Script source code.
+   * \param pre_data Pre-parsing data, as obtained by ScriptData::PreCompile()
+   *   using pre_data speeds compilation if it's done multiple times.
+   *   Owned by caller, no references are kept when this function returns.
+   * \return Compiled script object, bound to the context that was active
+   *   when this function was called. When run it will always use this
+   *   context.
+   */
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<Script> Compile(Isolate* isolate, Source* source,
+                            CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Returns a task which streams script data into V8, or NULL if the script
+   * cannot be streamed. The user is responsible for running the task on a
+   * background thread and deleting it. When ran, the task starts parsing the
+   * script, and it will request data from the StreamedSource as needed. When
+   * ScriptStreamingTask::Run exits, all data has been streamed and the script
+   * can be compiled (see Compile below).
+   *
+   * This API allows to start the streaming with as little data as possible, and
+   * the remaining data (for example, the ScriptOrigin) is passed to Compile.
+   */
+  static ScriptStreamingTask* StartStreamingScript(
+      Isolate* isolate, StreamedSource* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles a streamed script (bound to current context).
+   *
+   * This can only be called after the streaming has finished
+   * (ScriptStreamingTask has been run). V8 doesn't construct the source string
+   * during streaming, so the embedder needs to pass the full source here.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<Script> Compile(Isolate* isolate,
+                                             StreamedSource* source,
+                                             Local<String> full_source_string,
+                                             const ScriptOrigin& origin));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, StreamedSource* source,
+      Local<String> full_source_string, const ScriptOrigin& origin);
+
+  /**
+   * Return a version tag for CachedData for the current V8 version & flags.
+   *
+   * This value is meant only for determining whether a previously generated
+   * CachedData instance is still valid; the tag has no other meaing.
+   *
+   * Background: The data carried by CachedData may depend on the exact
+   *   V8 version number or current compiler flags. This means that when
+   *   persisting CachedData, the embedder must take care to not pass in
+   *   data from another V8 version, or the same version with different
+   *   features enabled.
+   *
+   *   The easiest way to do so is to clear the embedder's cache on any
+   *   such change.
+   *
+   *   Alternatively, this tag can be stored alongside the cached data and
+   *   compared when it is being used.
+   */
+  static uint32_t CachedDataVersionTag();
+
+  /**
+   * This is an unfinished experimental feature, and is only exposed
+   * here for internal testing purposes. DO NOT USE.
+   *
+   * Compile an ES module, returning a Module that encapsulates
+   * the compiled code.
+   *
+   * Corresponds to the ParseModule abstract operation in the
+   * ECMAScript specification.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Module> CompileModule(
+      Isolate* isolate, Source* source);
+
+  /**
+   * Compile a function for a given context. This is equivalent to running
+   *
+   * with (obj) {
+   *   return function(args) { ... }
+   * }
+   *
+   * It is possible to specify multiple context extensions (obj in the above
+   * example).
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Function> CompileFunctionInContext(
+                               Isolate* isolate, Source* source,
+                               Local<Context> context, size_t arguments_count,
+                               Local<String> arguments[],
+                               size_t context_extension_count,
+                               Local<Object> context_extensions[]));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Function> CompileFunctionInContext(
+      Local<Context> context, Source* source, size_t arguments_count,
+      Local<String> arguments[], size_t context_extension_count,
+      Local<Object> context_extensions[]);
+
+ private:
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundInternal(
+      Isolate* isolate, Source* source, CompileOptions options);
+};
+
+
+/**
+ * An error message.
+ */
+class V8_EXPORT Message {
+ public:
+  Local<String> Get() const;
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<String> GetSourceLine() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> GetSourceLine(
+      Local<Context> context) const;
+
+  /**
+   * Returns the origin for the script from where the function causing the
+   * error originates.
+   */
+  ScriptOrigin GetScriptOrigin() const;
+
+  /**
+   * Returns the resource name for the script from where the function causing
+   * the error originates.
+   */
+  Local<Value> GetScriptResourceName() const;
+
+  /**
+   * Exception stack trace. By default stack traces are not captured for
+   * uncaught exceptions. SetCaptureStackTraceForUncaughtExceptions allows
+   * to change this option.
+   */
+  Local<StackTrace> GetStackTrace() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetLineNumber() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetLineNumber(Local<Context> context) const;
+
+  /**
+   * Returns the index within the script of the first character where
+   * the error occurred.
+   */
+  int GetStartPosition() const;
+
+  /**
+   * Returns the index within the script of the last character where
+   * the error occurred.
+   */
+  int GetEndPosition() const;
+
+  /**
+   * Returns the error level of the message.
+   */
+  int ErrorLevel() const;
+
+  /**
+   * Returns the index within the line of the first character where
+   * the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetStartColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetStartColumn(Local<Context> context) const;
+
+  /**
+   * Returns the index within the line of the last character where
+   * the error occurred.
+   */
+  V8_DEPRECATED("Use maybe version", int GetEndColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetEndColumn(Local<Context> context) const;
+
+  /**
+   * Passes on the value set by the embedder when it fed the script from which
+   * this Message was generated to V8.
+   */
+  bool IsSharedCrossOrigin() const;
+  bool IsOpaque() const;
+
+  // TODO(1245381): Print to a string instead of on a FILE.
+  static void PrintCurrentStackTrace(Isolate* isolate, FILE* out);
+
+  static const int kNoLineNumberInfo = 0;
+  static const int kNoColumnInfo = 0;
+  static const int kNoScriptIdInfo = 0;
+};
+
+
+/**
+ * Representation of a JavaScript stack trace. The information collected is a
+ * snapshot of the execution stack and the information remains valid after
+ * execution continues.
+ */
+class V8_EXPORT StackTrace {
+ public:
+  /**
+   * Flags that determine what information is placed captured for each
+   * StackFrame when grabbing the current stack trace.
+   * Note: these options are deprecated and we always collect all available
+   * information (kDetailed).
+   */
+  enum StackTraceOptions {
+    kLineNumber = 1,
+    kColumnOffset = 1 << 1 | kLineNumber,
+    kScriptName = 1 << 2,
+    kFunctionName = 1 << 3,
+    kIsEval = 1 << 4,
+    kIsConstructor = 1 << 5,
+    kScriptNameOrSourceURL = 1 << 6,
+    kScriptId = 1 << 7,
+    kExposeFramesAcrossSecurityOrigins = 1 << 8,
+    kOverview = kLineNumber | kColumnOffset | kScriptName | kFunctionName,
+    kDetailed = kOverview | kIsEval | kIsConstructor | kScriptNameOrSourceURL
+  };
+
+  /**
+   * Returns a StackFrame at a particular index.
+   */
+  Local<StackFrame> GetFrame(uint32_t index) const;
+
+  /**
+   * Returns the number of StackFrames.
+   */
+  int GetFrameCount() const;
+
+  /**
+   * Returns StackTrace as a v8::Array that contains StackFrame objects.
+   */
+  V8_DEPRECATED("Use native API instead", Local<Array> AsArray());
+
+  /**
+   * Grab a snapshot of the current JavaScript execution stack.
+   *
+   * \param frame_limit The maximum number of stack frames we want to capture.
+   * \param options Enumerates the set of things we will capture for each
+   *   StackFrame.
+   */
+  static Local<StackTrace> CurrentStackTrace(
+      Isolate* isolate, int frame_limit, StackTraceOptions options = kDetailed);
+};
+
+
+/**
+ * A single JavaScript stack frame.
+ */
+class V8_EXPORT StackFrame {
+ public:
+  /**
+   * Returns the number, 1-based, of the line for the associate function call.
+   * This method will return Message::kNoLineNumberInfo if it is unable to
+   * retrieve the line number, or if kLineNumber was not passed as an option
+   * when capturing the StackTrace.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns the 1-based column offset on the line for the associated function
+   * call.
+   * This method will return Message::kNoColumnInfo if it is unable to retrieve
+   * the column number, or if kColumnOffset was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetColumn() const;
+
+  /**
+   * Returns the id of the script for the function for this StackFrame.
+   * This method will return Message::kNoScriptIdInfo if it is unable to
+   * retrieve the script id, or if kScriptId was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetScriptId() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame.
+   */
+  Local<String> GetScriptName() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame or sourceURL value if the script name
+   * is undefined and its source ends with //# sourceURL=... string or
+   * deprecated //@ sourceURL=... string.
+   */
+  Local<String> GetScriptNameOrSourceURL() const;
+
+  /**
+   * Returns the name of the function associated with this stack frame.
+   */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns whether or not the associated function is compiled via a call to
+   * eval().
+   */
+  bool IsEval() const;
+
+  /**
+   * Returns whether or not the associated function is called as a
+   * constructor via "new".
+   */
+  bool IsConstructor() const;
+
+  /**
+   * Returns whether or not the associated functions is defined in wasm.
+   */
+  bool IsWasm() const;
+};
+
+
+// A StateTag represents a possible state of the VM.
+enum StateTag { JS, GC, COMPILER, OTHER, EXTERNAL, IDLE };
+
+// A RegisterState represents the current state of registers used
+// by the sampling profiler API.
+struct RegisterState {
+  RegisterState() : pc(nullptr), sp(nullptr), fp(nullptr) {}
+  void* pc;  // Instruction pointer.
+  void* sp;  // Stack pointer.
+  void* fp;  // Frame pointer.
+};
+
+// The output structure filled up by GetStackSample API function.
+struct SampleInfo {
+  size_t frames_count;            // Number of frames collected.
+  StateTag vm_state;              // Current VM state.
+  void* external_callback_entry;  // External callback address if VM is
+                                  // executing an external callback.
+};
+
+/**
+ * A JSON Parser and Stringifier.
+ */
+class V8_EXPORT JSON {
+ public:
+  /**
+   * Tries to parse the string |json_string| and returns it as value if
+   * successful.
+   *
+   * \param json_string The string to parse.
+   * \return The corresponding value if successfully parsed.
+   */
+  static V8_DEPRECATED("Use the maybe version taking context",
+                       Local<Value> Parse(Local<String> json_string));
+  static V8_DEPRECATE_SOON("Use the maybe version taking context",
+                           MaybeLocal<Value> Parse(Isolate* isolate,
+                                                   Local<String> json_string));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> Parse(
+      Local<Context> context, Local<String> json_string);
+
+  /**
+   * Tries to stringify the JSON-serializable object |json_object| and returns
+   * it as string if successful.
+   *
+   * \param json_object The JSON-serializable object to stringify.
+   * \return The corresponding string if successfully stringified.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> Stringify(
+      Local<Context> context, Local<Object> json_object,
+      Local<String> gap = Local<String>());
+};
+
+/**
+ * Value serialization compatible with the HTML structured clone algorithm.
+ * The format is backward-compatible (i.e. safe to store to disk).
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueSerializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * Handles the case where a DataCloneError would be thrown in the structured
+     * clone spec. Other V8 embedders may throw some other appropriate exception
+     * type.
+     */
+    virtual void ThrowDataCloneError(Local<String> message) = 0;
+
+    /**
+     * The embedder overrides this method to write some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * Nothing<bool>() returned.
+     */
+    virtual Maybe<bool> WriteHostObject(Isolate* isolate, Local<Object> object);
+
+    /**
+     * Called when the ValueSerializer is going to serialize a
+     * SharedArrayBuffer object. The embedder must return an ID for the
+     * object, using the same ID if this SharedArrayBuffer has already been
+     * serialized in this buffer. When deserializing, this ID will be passed to
+     * ValueDeserializer::TransferSharedArrayBuffer as |transfer_id|.
+     *
+     * If the object cannot be serialized, an
+     * exception should be thrown and Nothing<uint32_t>() returned.
+     */
+    virtual Maybe<uint32_t> GetSharedArrayBufferId(
+        Isolate* isolate, Local<SharedArrayBuffer> shared_array_buffer);
+
+    virtual Maybe<uint32_t> GetWasmModuleTransferId(
+        Isolate* isolate, Local<WasmCompiledModule> module);
+    /**
+     * Allocates memory for the buffer of at least the size provided. The actual
+     * size (which may be greater or equal) is written to |actual_size|. If no
+     * buffer has been allocated yet, nullptr will be provided.
+     *
+     * If the memory cannot be allocated, nullptr should be returned.
+     * |actual_size| will be ignored. It is assumed that |old_buffer| is still
+     * valid in this case and has not been modified.
+     */
+    virtual void* ReallocateBufferMemory(void* old_buffer, size_t size,
+                                         size_t* actual_size);
+
+    /**
+     * Frees a buffer allocated with |ReallocateBufferMemory|.
+     */
+    virtual void FreeBufferMemory(void* buffer);
+  };
+
+  explicit ValueSerializer(Isolate* isolate);
+  ValueSerializer(Isolate* isolate, Delegate* delegate);
+  ~ValueSerializer();
+
+  /**
+   * Writes out a header, which includes the format version.
+   */
+  void WriteHeader();
+
+  /**
+   * Serializes a JavaScript value into the buffer.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> WriteValue(Local<Context> context,
+                                               Local<Value> value);
+
+  /**
+   * Returns the stored data. This serializer should not be used once the buffer
+   * is released. The contents are undefined if a previous write has failed.
+   */
+  V8_DEPRECATE_SOON("Use Release()", std::vector<uint8_t> ReleaseBuffer());
+
+  /**
+   * Returns the stored data (allocated using the delegate's
+   * AllocateBufferMemory) and its size. This serializer should not be used once
+   * the buffer is released. The contents are undefined if a previous write has
+   * failed.
+   */
+  V8_WARN_UNUSED_RESULT std::pair<uint8_t*, size_t> Release();
+
+  /**
+   * Marks an ArrayBuffer as havings its contents transferred out of band.
+   * Pass the corresponding ArrayBuffer in the deserializing context to
+   * ValueDeserializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   */
+  V8_DEPRECATE_SOON("Use Delegate::GetSharedArrayBufferId",
+                    void TransferSharedArrayBuffer(
+                        uint32_t transfer_id,
+                        Local<SharedArrayBuffer> shared_array_buffer));
+
+  /**
+   * Indicate whether to treat ArrayBufferView objects as host objects,
+   * i.e. pass them to Delegate::WriteHostObject. This should not be
+   * called when no Delegate was passed.
+   *
+   * The default is not to treat ArrayBufferViews as host objects.
+   */
+  void SetTreatArrayBufferViewsAsHostObjects(bool mode);
+
+  /**
+   * Write raw data in various common formats to the buffer.
+   * Note that integer types are written in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::WriteHostObject.
+   */
+  void WriteUint32(uint32_t value);
+  void WriteUint64(uint64_t value);
+  void WriteDouble(double value);
+  void WriteRawBytes(const void* source, size_t length);
+
+ private:
+  ValueSerializer(const ValueSerializer&) = delete;
+  void operator=(const ValueSerializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * Deserializes values from data written with ValueSerializer, or a compatible
+ * implementation.
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueDeserializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * The embedder overrides this method to read some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * MaybeLocal<Object>() returned.
+     */
+    virtual MaybeLocal<Object> ReadHostObject(Isolate* isolate);
+
+    /**
+     * Get a WasmCompiledModule given a transfer_id previously provided
+     * by ValueSerializer::GetWasmModuleTransferId
+     */
+    virtual MaybeLocal<WasmCompiledModule> GetWasmModuleFromId(
+        Isolate* isolate, uint32_t transfer_id);
+  };
+
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size);
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size,
+                    Delegate* delegate);
+  ~ValueDeserializer();
+
+  /**
+   * Reads and validates a header (including the format version).
+   * May, for example, reject an invalid or unsupported wire format.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> ReadHeader(Local<Context> context);
+
+  /**
+   * Deserializes a JavaScript value from the buffer.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> ReadValue(Local<Context> context);
+
+  /**
+   * Accepts the array buffer corresponding to the one passed previously to
+   * ValueSerializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   * The id is not necessarily in the same namespace as unshared ArrayBuffer
+   * objects.
+   */
+  void TransferSharedArrayBuffer(uint32_t id,
+                                 Local<SharedArrayBuffer> shared_array_buffer);
+
+  /**
+   * Must be called before ReadHeader to enable support for reading the legacy
+   * wire format (i.e., which predates this being shipped).
+   *
+   * Don't use this unless you need to read data written by previous versions of
+   * blink::ScriptValueSerializer.
+   */
+  void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);
+
+  /**
+   * Expect inline wasm in the data stream (rather than in-memory transfer)
+   */
+  void SetExpectInlineWasm(bool allow_inline_wasm);
+
+  /**
+   * Reads the underlying wire format version. Likely mostly to be useful to
+   * legacy code reading old wire format versions. Must be called after
+   * ReadHeader.
+   */
+  uint32_t GetWireFormatVersion() const;
+
+  /**
+   * Reads raw data in various common formats to the buffer.
+   * Note that integer types are read in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::ReadHostObject.
+   */
+  V8_WARN_UNUSED_RESULT bool ReadUint32(uint32_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadUint64(uint64_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadDouble(double* value);
+  V8_WARN_UNUSED_RESULT bool ReadRawBytes(size_t length, const void** data);
+
+ private:
+  ValueDeserializer(const ValueDeserializer&) = delete;
+  void operator=(const ValueDeserializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * A map whose keys are referenced weakly. It is similar to JavaScript WeakMap
+ * but can be created without entering a v8::Context and hence shouldn't
+ * escape to JavaScript.
+ */
+class V8_EXPORT NativeWeakMap : public Data {
+ public:
+  static Local<NativeWeakMap> New(Isolate* isolate);
+  void Set(Local<Value> key, Local<Value> value);
+  Local<Value> Get(Local<Value> key) const;
+  bool Has(Local<Value> key);
+  bool Delete(Local<Value> key);
+};
+
+
+// --- Value ---
+
+
+/**
+ * The superclass of all JavaScript values and objects.
+ */
+class V8_EXPORT Value : public Data {
+ public:
+  /**
+   * Returns true if this value is the undefined value.  See ECMA-262
+   * 4.3.10.
+   */
+  V8_INLINE bool IsUndefined() const;
+
+  /**
+   * Returns true if this value is the null value.  See ECMA-262
+   * 4.3.11.
+   */
+  V8_INLINE bool IsNull() const;
+
+  /**
+   * Returns true if this value is either the null or the undefined value.
+   * See ECMA-262
+   * 4.3.11. and 4.3.12
+   */
+  V8_INLINE bool IsNullOrUndefined() const;
+
+  /**
+  * Returns true if this value is true.
+  */
+  bool IsTrue() const;
+
+  /**
+   * Returns true if this value is false.
+   */
+  bool IsFalse() const;
+
+  /**
+   * Returns true if this value is a symbol or a string.
+   */
+  bool IsName() const;
+
+  /**
+   * Returns true if this value is an instance of the String type.
+   * See ECMA-262 8.4.
+   */
+  V8_INLINE bool IsString() const;
+
+  /**
+   * Returns true if this value is a symbol.
+   */
+  bool IsSymbol() const;
+
+  /**
+   * Returns true if this value is a function.
+   */
+  bool IsFunction() const;
+
+  /**
+   * Returns true if this value is an array. Note that it will return false for
+   * an Proxy for an array.
+   */
+  bool IsArray() const;
+
+  /**
+   * Returns true if this value is an object.
+   */
+  bool IsObject() const;
+
+  /**
+   * Returns true if this value is boolean.
+   */
+  bool IsBoolean() const;
+
+  /**
+   * Returns true if this value is a number.
+   */
+  bool IsNumber() const;
+
+  /**
+   * Returns true if this value is external.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this value is a 32-bit signed integer.
+   */
+  bool IsInt32() const;
+
+  /**
+   * Returns true if this value is a 32-bit unsigned integer.
+   */
+  bool IsUint32() const;
+
+  /**
+   * Returns true if this value is a Date.
+   */
+  bool IsDate() const;
+
+  /**
+   * Returns true if this value is an Arguments object.
+   */
+  bool IsArgumentsObject() const;
+
+  /**
+   * Returns true if this value is a Boolean object.
+   */
+  bool IsBooleanObject() const;
+
+  /**
+   * Returns true if this value is a Number object.
+   */
+  bool IsNumberObject() const;
+
+  /**
+   * Returns true if this value is a String object.
+   */
+  bool IsStringObject() const;
+
+  /**
+   * Returns true if this value is a Symbol object.
+   */
+  bool IsSymbolObject() const;
+
+  /**
+   * Returns true if this value is a NativeError.
+   */
+  bool IsNativeError() const;
+
+  /**
+   * Returns true if this value is a RegExp.
+   */
+  bool IsRegExp() const;
+
+  /**
+   * Returns true if this value is an async function.
+   */
+  bool IsAsyncFunction() const;
+
+  /**
+   * Returns true if this value is a Generator function.
+   */
+  bool IsGeneratorFunction() const;
+
+  /**
+   * Returns true if this value is a Generator object (iterator).
+   */
+  bool IsGeneratorObject() const;
+
+  /**
+   * Returns true if this value is a Promise.
+   */
+  bool IsPromise() const;
+
+  /**
+   * Returns true if this value is a Map.
+   */
+  bool IsMap() const;
+
+  /**
+   * Returns true if this value is a Set.
+   */
+  bool IsSet() const;
+
+  /**
+   * Returns true if this value is a Map Iterator.
+   */
+  bool IsMapIterator() const;
+
+  /**
+   * Returns true if this value is a Set Iterator.
+   */
+  bool IsSetIterator() const;
+
+  /**
+   * Returns true if this value is a WeakMap.
+   */
+  bool IsWeakMap() const;
+
+  /**
+   * Returns true if this value is a WeakSet.
+   */
+  bool IsWeakSet() const;
+
+  /**
+   * Returns true if this value is an ArrayBuffer.
+   */
+  bool IsArrayBuffer() const;
+
+  /**
+   * Returns true if this value is an ArrayBufferView.
+   */
+  bool IsArrayBufferView() const;
+
+  /**
+   * Returns true if this value is one of TypedArrays.
+   */
+  bool IsTypedArray() const;
+
+  /**
+   * Returns true if this value is an Uint8Array.
+   */
+  bool IsUint8Array() const;
+
+  /**
+   * Returns true if this value is an Uint8ClampedArray.
+   */
+  bool IsUint8ClampedArray() const;
+
+  /**
+   * Returns true if this value is an Int8Array.
+   */
+  bool IsInt8Array() const;
+
+  /**
+   * Returns true if this value is an Uint16Array.
+   */
+  bool IsUint16Array() const;
+
+  /**
+   * Returns true if this value is an Int16Array.
+   */
+  bool IsInt16Array() const;
+
+  /**
+   * Returns true if this value is an Uint32Array.
+   */
+  bool IsUint32Array() const;
+
+  /**
+   * Returns true if this value is an Int32Array.
+   */
+  bool IsInt32Array() const;
+
+  /**
+   * Returns true if this value is a Float32Array.
+   */
+  bool IsFloat32Array() const;
+
+  /**
+   * Returns true if this value is a Float64Array.
+   */
+  bool IsFloat64Array() const;
+
+  /**
+   * Returns true if this value is a DataView.
+   */
+  bool IsDataView() const;
+
+  /**
+   * Returns true if this value is a SharedArrayBuffer.
+   * This is an experimental feature.
+   */
+  bool IsSharedArrayBuffer() const;
+
+  /**
+   * Returns true if this value is a JavaScript Proxy.
+   */
+  bool IsProxy() const;
+
+  bool IsWebAssemblyCompiledModule() const;
+
+  V8_WARN_UNUSED_RESULT MaybeLocal<Boolean> ToBoolean(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToDetailString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> ToObject(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Integer> ToInteger(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToUint32(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Int32> ToInt32(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Boolean> ToBoolean(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Number> ToNumber(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<String> ToString(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<String> ToDetailString(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Object> ToObject(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Integer> ToInteger(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<Uint32> ToUint32(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Int32> ToInt32(Isolate* isolate) const);
+
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Boolean> ToBoolean() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Number> ToNumber() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<String> ToString() const);
+  inline V8_DEPRECATED("Use maybe version",
+                       Local<String> ToDetailString() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<Object> ToObject() const);
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Integer> ToInteger() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Uint32> ToUint32() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Int32> ToInt32() const);
+
+  /**
+   * Attempts to convert a string to an array index.
+   * Returns an empty handle if the conversion fails.
+   */
+  V8_DEPRECATED("Use maybe version", Local<Uint32> ToArrayIndex() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToArrayIndex(
+      Local<Context> context) const;
+
+  V8_WARN_UNUSED_RESULT Maybe<bool> BooleanValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<double> NumberValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int64_t> IntegerValue(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<uint32_t> Uint32Value(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int32_t> Int32Value(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version", bool BooleanValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", double NumberValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", int64_t IntegerValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", uint32_t Uint32Value() const);
+  V8_DEPRECATE_SOON("Use maybe version", int32_t Int32Value() const);
+
+  /** JS == */
+  V8_DEPRECATE_SOON("Use maybe version", bool Equals(Local<Value> that) const);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Equals(Local<Context> context,
+                                           Local<Value> that) const;
+  bool StrictEquals(Local<Value> that) const;
+  bool SameValue(Local<Value> that) const;
+
+  template <class T> V8_INLINE static Value* Cast(T* value);
+
+  Local<String> TypeOf(Isolate*);
+
+  Maybe<bool> InstanceOf(Local<Context> context, Local<Object> object);
+
+ private:
+  V8_INLINE bool QuickIsUndefined() const;
+  V8_INLINE bool QuickIsNull() const;
+  V8_INLINE bool QuickIsNullOrUndefined() const;
+  V8_INLINE bool QuickIsString() const;
+  bool FullIsUndefined() const;
+  bool FullIsNull() const;
+  bool FullIsString() const;
+};
+
+
+/**
+ * The superclass of primitive values.  See ECMA-262 4.3.2.
+ */
+class V8_EXPORT Primitive : public Value { };
+
+
+/**
+ * A primitive boolean value (ECMA-262, 4.3.14).  Either the true
+ * or false value.
+ */
+class V8_EXPORT Boolean : public Primitive {
+ public:
+  bool Value() const;
+  V8_INLINE static Boolean* Cast(v8::Value* obj);
+  V8_INLINE static Local<Boolean> New(Isolate* isolate, bool value);
+
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A superclass for symbols and strings.
+ */
+class V8_EXPORT Name : public Primitive {
+ public:
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses an inline property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  V8_INLINE static Name* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * A flag describing different modes of string creation.
+ *
+ * Aside from performance implications there are no differences between the two
+ * creation modes.
+ */
+enum class NewStringType {
+  /**
+   * Create a new string, always allocating new storage memory.
+   */
+  kNormal,
+
+  /**
+   * Acts as a hint that the string should be created in the
+   * old generation heap space and be deduplicated if an identical string
+   * already exists.
+   */
+  kInternalized
+};
+
+/**
+ * A JavaScript string value (ECMA-262, 4.3.17).
+ */
+class V8_EXPORT String : public Name {
+ public:
+  static const int kMaxLength = (1 << 28) - 16;
+
+  enum Encoding {
+    UNKNOWN_ENCODING = 0x1,
+    TWO_BYTE_ENCODING = 0x0,
+    ONE_BYTE_ENCODING = 0x8
+  };
+  /**
+   * Returns the number of characters (UTF-16 code units) in this string.
+   */
+  int Length() const;
+
+  /**
+   * Returns the number of bytes in the UTF-8 encoded
+   * representation of this string.
+   */
+  int Utf8Length() const;
+
+  /**
+   * Returns whether this string is known to contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Does not read the string.
+   * False negatives are possible.
+   */
+  bool IsOneByte() const;
+
+  /**
+   * Returns whether this string contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Will read the entire string in some cases.
+   */
+  bool ContainsOnlyOneByte() const;
+
+  /**
+   * Write the contents of the string to an external buffer.
+   * If no arguments are given, expects the buffer to be large
+   * enough to hold the entire string and NULL terminator. Copies
+   * the contents of the string and the NULL terminator into the
+   * buffer.
+   *
+   * WriteUtf8 will not write partial UTF-8 sequences, preferring to stop
+   * before the end of the buffer.
+   *
+   * Copies up to length characters into the output buffer.
+   * Only null-terminates if there is enough space in the buffer.
+   *
+   * \param buffer The buffer into which the string will be copied.
+   * \param start The starting position within the string at which
+   * copying begins.
+   * \param length The number of characters to copy from the string.  For
+   *    WriteUtf8 the number of bytes in the buffer.
+   * \param nchars_ref The number of characters written, can be NULL.
+   * \param options Various options that might affect performance of this or
+   *    subsequent operations.
+   * \return The number of characters copied to the buffer excluding the null
+   *    terminator.  For WriteUtf8: The number of bytes copied to the buffer
+   *    including the null terminator (if written).
+   */
+  enum WriteOptions {
+    NO_OPTIONS = 0,
+    HINT_MANY_WRITES_EXPECTED = 1,
+    NO_NULL_TERMINATION = 2,
+    PRESERVE_ONE_BYTE_NULL = 4,
+    // Used by WriteUtf8 to replace orphan surrogate code units with the
+    // unicode replacement character. Needs to be set to guarantee valid UTF-8
+    // output.
+    REPLACE_INVALID_UTF8 = 8
+  };
+
+  // 16-bit character codes.
+  int Write(uint16_t* buffer,
+            int start = 0,
+            int length = -1,
+            int options = NO_OPTIONS) const;
+  // One byte characters.
+  int WriteOneByte(uint8_t* buffer,
+                   int start = 0,
+                   int length = -1,
+                   int options = NO_OPTIONS) const;
+  // UTF-8 encoded characters.
+  int WriteUtf8(char* buffer,
+                int length = -1,
+                int* nchars_ref = NULL,
+                int options = NO_OPTIONS) const;
+
+  /**
+   * A zero length string.
+   */
+  V8_INLINE static Local<String> Empty(Isolate* isolate);
+
+  /**
+   * Returns true if the string is external
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if the string is both external and one-byte.
+   */
+  bool IsExternalOneByte() const;
+
+  class V8_EXPORT ExternalStringResourceBase {  // NOLINT
+   public:
+    virtual ~ExternalStringResourceBase() {}
+
+    virtual bool IsCompressible() const { return false; }
+
+   protected:
+    ExternalStringResourceBase() {}
+
+    /**
+     * Internally V8 will call this Dispose method when the external string
+     * resource is no longer needed. The default implementation will use the
+     * delete operator. This method can be overridden in subclasses to
+     * control how allocated external string resources are disposed.
+     */
+    virtual void Dispose() { delete this; }
+
+    // Disallow copying and assigning.
+    ExternalStringResourceBase(const ExternalStringResourceBase&) = delete;
+    void operator=(const ExternalStringResourceBase&) = delete;
+
+   private:
+    friend class internal::Heap;
+    friend class v8::String;
+  };
+
+  /**
+   * An ExternalStringResource is a wrapper around a two-byte string
+   * buffer that resides outside V8's heap. Implement an
+   * ExternalStringResource to manage the life cycle of the underlying
+   * buffer.  Note that the string data must be immutable.
+   */
+  class V8_EXPORT ExternalStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalStringResource() {}
+
+    /**
+     * The string data from the underlying buffer.
+     */
+    virtual const uint16_t* data() const = 0;
+
+    /**
+     * The length of the string. That is, the number of two-byte characters.
+     */
+    virtual size_t length() const = 0;
+
+   protected:
+    ExternalStringResource() {}
+  };
+
+  /**
+   * An ExternalOneByteStringResource is a wrapper around an one-byte
+   * string buffer that resides outside V8's heap. Implement an
+   * ExternalOneByteStringResource to manage the life cycle of the
+   * underlying buffer.  Note that the string data must be immutable
+   * and that the data must be Latin-1 and not UTF-8, which would require
+   * special treatment internally in the engine and do not allow efficient
+   * indexing.  Use String::New or convert to 16 bit data for non-Latin1.
+   */
+
+  class V8_EXPORT ExternalOneByteStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalOneByteStringResource() {}
+    /** The string data from the underlying buffer.*/
+    virtual const char* data() const = 0;
+    /** The number of Latin-1 characters in the string.*/
+    virtual size_t length() const = 0;
+   protected:
+    ExternalOneByteStringResource() {}
+  };
+
+  /**
+   * If the string is an external string, return the ExternalStringResourceBase
+   * regardless of the encoding, otherwise return NULL.  The encoding of the
+   * string is returned in encoding_out.
+   */
+  V8_INLINE ExternalStringResourceBase* GetExternalStringResourceBase(
+      Encoding* encoding_out) const;
+
+  /**
+   * Get the ExternalStringResource for an external string.  Returns
+   * NULL if IsExternal() doesn't return true.
+   */
+  V8_INLINE ExternalStringResource* GetExternalStringResource() const;
+
+  /**
+   * Get the ExternalOneByteStringResource for an external one-byte string.
+   * Returns NULL if IsExternalOneByte() doesn't return true.
+   */
+  const ExternalOneByteStringResource* GetExternalOneByteStringResource() const;
+
+  V8_INLINE static String* Cast(v8::Value* obj);
+
+  // TODO(dcarney): remove with deprecation of New functions.
+  enum NewStringType {
+    kNormalString = static_cast<int>(v8::NewStringType::kNormal),
+    kInternalizedString = static_cast<int>(v8::NewStringType::kInternalized)
+  };
+
+  /** Allocates a new string from UTF-8 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromUtf8(Isolate* isolate, const char* data,
+                                NewStringType type = kNormalString,
+                                int length = -1));
+
+  /** Allocates a new string from UTF-8 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromUtf8(
+      Isolate* isolate, const char* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from Latin-1 data.*/
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<String> NewFromOneByte(Isolate* isolate, const uint8_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from Latin-1 data.  Only returns an empty value
+   * when length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromOneByte(
+      Isolate* isolate, const uint8_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from UTF-16 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromTwoByte(Isolate* isolate, const uint16_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from UTF-16 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromTwoByte(
+      Isolate* isolate, const uint16_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /**
+   * Creates a new string by concatenating the left and the right strings
+   * passed in as parameters.
+   */
+  static Local<String> Concat(Local<String> left, Local<String> right);
+
+  /**
+   * Creates a new external string using the data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<String> NewExternal(
+                           Isolate* isolate, ExternalStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalTwoByte(
+      Isolate* isolate, ExternalStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalStringResource* resource);
+
+  /**
+   * Creates a new external string using the one-byte data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewExternal(Isolate* isolate,
+                                ExternalOneByteStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalOneByte(
+      Isolate* isolate, ExternalOneByteStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalOneByteStringResource* resource);
+
+  /**
+   * Returns true if this string can be made external.
+   */
+  bool CanMakeExternal();
+
+  /**
+   * Converts an object to a UTF-8-encoded character array.  Useful if
+   * you want to print the object.  If conversion to a string fails
+   * (e.g. due to an exception in the toString() method of the object)
+   * then the length() method returns 0 and the * operator returns
+   * NULL.
+   */
+  class V8_EXPORT Utf8Value {
+   public:
+    explicit Utf8Value(Local<v8::Value> obj);
+    ~Utf8Value();
+    char* operator*() { return str_; }
+    const char* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Utf8Value(const Utf8Value&) = delete;
+    void operator=(const Utf8Value&) = delete;
+
+   private:
+    char* str_;
+    int length_;
+  };
+
+  /**
+   * Converts an object to a two-byte (UTF-16-encoded) string.
+   * If conversion to a string fails (eg. due to an exception in the toString()
+   * method of the object) then the length() method returns 0 and the * operator
+   * returns NULL.
+   */
+  class V8_EXPORT Value {
+   public:
+    explicit Value(Local<v8::Value> obj);
+    ~Value();
+    uint16_t* operator*() { return str_; }
+    const uint16_t* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Value(const Value&) = delete;
+    void operator=(const Value&) = delete;
+
+   private:
+    uint16_t* str_;
+    int length_;
+  };
+
+ private:
+  void VerifyExternalStringResourceBase(ExternalStringResourceBase* v,
+                                        Encoding encoding) const;
+  void VerifyExternalStringResource(ExternalStringResource* val) const;
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript symbol (ECMA-262 edition 6)
+ */
+class V8_EXPORT Symbol : public Name {
+ public:
+  /**
+   * Returns the print name string of the symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a symbol. If name is not empty, it will be used as the description.
+   */
+  static Local<Symbol> New(Isolate* isolate,
+                           Local<String> name = Local<String>());
+
+  /**
+   * Access global symbol registry.
+   * Note that symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys.
+   */
+  static Local<Symbol> For(Isolate *isolate, Local<String> name);
+
+  /**
+   * Retrieve a global symbol. Similar to |For|, but using a separate
+   * registry that is not accessible by (and cannot clash with) JavaScript code.
+   */
+  static Local<Symbol> ForApi(Isolate *isolate, Local<String> name);
+
+  // Well-known symbols
+  static Local<Symbol> GetHasInstance(Isolate* isolate);
+  static Local<Symbol> GetIsConcatSpreadable(Isolate* isolate);
+  static Local<Symbol> GetIterator(Isolate* isolate);
+  static Local<Symbol> GetMatch(Isolate* isolate);
+  static Local<Symbol> GetReplace(Isolate* isolate);
+  static Local<Symbol> GetSearch(Isolate* isolate);
+  static Local<Symbol> GetSplit(Isolate* isolate);
+  static Local<Symbol> GetToPrimitive(Isolate* isolate);
+  static Local<Symbol> GetToStringTag(Isolate* isolate);
+  static Local<Symbol> GetUnscopables(Isolate* isolate);
+
+  V8_INLINE static Symbol* Cast(Value* obj);
+
+ private:
+  Symbol();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A private symbol
+ *
+ * This is an experimental feature. Use at your own risk.
+ */
+class V8_EXPORT Private : public Data {
+ public:
+  /**
+   * Returns the print name string of the private symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a private symbol. If name is not empty, it will be the description.
+   */
+  static Local<Private> New(Isolate* isolate,
+                            Local<String> name = Local<String>());
+
+  /**
+   * Retrieve a global private symbol. If a symbol with this name has not
+   * been retrieved in the same isolate before, it is created.
+   * Note that private symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys,
+   * e.g., "Class#property".
+   */
+  static Local<Private> ForApi(Isolate* isolate, Local<String> name);
+
+ private:
+  Private();
+};
+
+
+/**
+ * A JavaScript number value (ECMA-262, 4.3.20)
+ */
+class V8_EXPORT Number : public Primitive {
+ public:
+  double Value() const;
+  static Local<Number> New(Isolate* isolate, double value);
+  V8_INLINE static Number* Cast(v8::Value* obj);
+ private:
+  Number();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a signed integer.
+ */
+class V8_EXPORT Integer : public Number {
+ public:
+  static Local<Integer> New(Isolate* isolate, int32_t value);
+  static Local<Integer> NewFromUnsigned(Isolate* isolate, uint32_t value);
+  int64_t Value() const;
+  V8_INLINE static Integer* Cast(v8::Value* obj);
+ private:
+  Integer();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit signed integer.
+ */
+class V8_EXPORT Int32 : public Integer {
+ public:
+  int32_t Value() const;
+  V8_INLINE static Int32* Cast(v8::Value* obj);
+
+ private:
+  Int32();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit unsigned integer.
+ */
+class V8_EXPORT Uint32 : public Integer {
+ public:
+  uint32_t Value() const;
+  V8_INLINE static Uint32* Cast(v8::Value* obj);
+
+ private:
+  Uint32();
+  static void CheckCast(v8::Value* obj);
+};
+
+/**
+ * PropertyAttribute.
+ */
+enum PropertyAttribute {
+  /** None. **/
+  None = 0,
+  /** ReadOnly, i.e., not writable. **/
+  ReadOnly = 1 << 0,
+  /** DontEnum, i.e., not enumerable. **/
+  DontEnum = 1 << 1,
+  /** DontDelete, i.e., not configurable. **/
+  DontDelete = 1 << 2
+};
+
+/**
+ * Accessor[Getter|Setter] are used as callback functions when
+ * setting|getting a particular property. See Object and ObjectTemplate's
+ * method SetAccessor.
+ */
+typedef void (*AccessorGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+typedef void (*AccessorNameGetterCallback)(
+    Local<Name> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+typedef void (*AccessorSetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+typedef void (*AccessorNameSetterCallback)(
+    Local<Name> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+
+
+/**
+ * Access control specifications.
+ *
+ * Some accessors should be accessible across contexts.  These
+ * accessors have an explicit access control parameter which specifies
+ * the kind of cross-context access that should be allowed.
+ *
+ * TODO(dcarney): Remove PROHIBITS_OVERWRITING as it is now unused.
+ */
+enum AccessControl {
+  DEFAULT               = 0,
+  ALL_CAN_READ          = 1,
+  ALL_CAN_WRITE         = 1 << 1,
+  PROHIBITS_OVERWRITING = 1 << 2
+};
+
+/**
+ * Property filter bits. They can be or'ed to build a composite filter.
+ */
+enum PropertyFilter {
+  ALL_PROPERTIES = 0,
+  ONLY_WRITABLE = 1,
+  ONLY_ENUMERABLE = 2,
+  ONLY_CONFIGURABLE = 4,
+  SKIP_STRINGS = 8,
+  SKIP_SYMBOLS = 16
+};
+
+/**
+ * Keys/Properties filter enums:
+ *
+ * KeyCollectionMode limits the range of collected properties. kOwnOnly limits
+ * the collected properties to the given Object only. kIncludesPrototypes will
+ * include all keys of the objects's prototype chain as well.
+ */
+enum class KeyCollectionMode { kOwnOnly, kIncludePrototypes };
+
+/**
+ * kIncludesIndices allows for integer indices to be collected, while
+ * kSkipIndices will exclude integer indicies from being collected.
+ */
+enum class IndexFilter { kIncludeIndices, kSkipIndices };
+
+/**
+ * Integrity level for objects.
+ */
+enum class IntegrityLevel { kFrozen, kSealed };
+
+/**
+ * A JavaScript object (ECMA-262, 4.3.3)
+ */
+class V8_EXPORT Object : public Value {
+ public:
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(Local<Value> key, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context,
+                                        Local<Value> key, Local<Value> value);
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(uint32_t index, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index,
+                                        Local<Value> value);
+
+  // Implements CreateDataProperty (ECMA-262, 7.3.4).
+  //
+  // Defines a configurable, writable, enumerable property with the given value
+  // on the object unless the property already exists and is not configurable
+  // or the object is not extensible.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       Local<Name> key,
+                                                       Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       uint32_t index,
+                                                       Local<Value> value);
+
+  // Implements DefineOwnProperty.
+  //
+  // In general, CreateDataProperty will be faster, however, does not allow
+  // for specifying attributes.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineOwnProperty(
+      Local<Context> context, Local<Name> key, Local<Value> value,
+      PropertyAttribute attributes = None);
+
+  // Implements Object.DefineProperty(O, P, Attributes), see Ecma-262 19.1.2.4.
+  //
+  // The defineProperty function is used to add an own property or
+  // update the attributes of an existing own property of an object.
+  //
+  // Both data and accessor descriptors can be used.
+  //
+  // In general, CreateDataProperty is faster, however, does not allow
+  // for specifying attributes or an accessor descriptor.
+  //
+  // The PropertyDescriptor can change when redefining a property.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineProperty(
+      Local<Context> context, Local<Name> key, PropertyDescriptor& descriptor);
+
+  // Sets an own property on this object bypassing interceptors and
+  // overriding accessors or read-only properties.
+  //
+  // Note that if the object has an interceptor the property will be set
+  // locally, but since the interceptor takes precedence the local property
+  // will only be returned if the interceptor doesn't return a value.
+  //
+  // Note also that this only works for named properties.
+  V8_DEPRECATED("Use CreateDataProperty / DefineOwnProperty",
+                bool ForceSet(Local<Value> key, Local<Value> value,
+                              PropertyAttribute attribs = None));
+  V8_DEPRECATE_SOON("Use CreateDataProperty / DefineOwnProperty",
+                    Maybe<bool> ForceSet(Local<Context> context,
+                                         Local<Value> key, Local<Value> value,
+                                         PropertyAttribute attribs = None));
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(Local<Value> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(uint32_t index));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              uint32_t index);
+
+  /**
+   * Gets the property attributes of a property which can be None or
+   * any combination of ReadOnly, DontEnum and DontDelete. Returns
+   * None when the property doesn't exist.
+   */
+  V8_DEPRECATED("Use maybe version",
+                PropertyAttribute GetPropertyAttributes(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetPropertyAttributes(
+      Local<Context> context, Local<Value> key);
+
+  /**
+   * Returns Object.getOwnPropertyDescriptor as per ES2016 section 19.1.2.6.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetOwnPropertyDescriptor(Local<Name> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetOwnPropertyDescriptor(
+      Local<Context> context, Local<Name> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Has(Local<Value> key));
+  /**
+   * Object::Has() calls the abstract operation HasProperty(O, P) described
+   * in ECMA-262, 7.3.10. Has() returns
+   * true, if the object has the property, either own or on the prototype chain.
+   * Interceptors, i.e., PropertyQueryCallbacks, are called if present.
+   *
+   * Has() has the same side effects as JavaScript's `variable in object`.
+   * For example, calling Has() on a revoked proxy will throw an exception.
+   *
+   * \note Has() converts the key to a name, which possibly calls back into
+   * JavaScript.
+   *
+   * See also v8::Object::HasOwnProperty() and
+   * v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Delete(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  V8_DEPRECATED("Use maybe version", bool Has(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        uint32_t index);
+
+  V8_DEPRECATED("Use maybe version", bool Delete(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           uint32_t index);
+
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<String> name,
+                                 AccessorGetterCallback getter,
+                                 AccessorSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<Name> name,
+                                 AccessorNameGetterCallback getter,
+                                 AccessorNameSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetAccessor(Local<Context> context,
+                          Local<Name> name,
+                          AccessorNameGetterCallback getter,
+                          AccessorNameSetterCallback setter = 0,
+                          MaybeLocal<Value> data = MaybeLocal<Value>(),
+                          AccessControl settings = DEFAULT,
+                          PropertyAttribute attribute = None);
+
+  void SetAccessorProperty(Local<Name> name, Local<Function> getter,
+                           Local<Function> setter = Local<Function>(),
+                           PropertyAttribute attribute = None,
+                           AccessControl settings = DEFAULT);
+
+  /**
+   * Sets a native data property like Template::SetNativeDataProperty, but
+   * this method sets on this object directly.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetNativeDataProperty(
+      Local<Context> context, Local<Name> name,
+      AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = nullptr,
+      Local<Value> data = Local<Value>(), PropertyAttribute attributes = None);
+
+  /**
+   * Functionality for private properties.
+   * This is an experimental feature, use at your own risk.
+   * Note: Private properties are not inherited. Do not rely on this, since it
+   * may change.
+   */
+  Maybe<bool> HasPrivate(Local<Context> context, Local<Private> key);
+  Maybe<bool> SetPrivate(Local<Context> context, Local<Private> key,
+                         Local<Value> value);
+  Maybe<bool> DeletePrivate(Local<Context> context, Local<Private> key);
+  MaybeLocal<Value> GetPrivate(Local<Context> context, Local<Private> key);
+
+  /**
+   * Returns an array containing the names of the enumerable properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context, KeyCollectionMode mode,
+      PropertyFilter property_filter, IndexFilter index_filter);
+
+  /**
+   * This function has the same functionality as GetPropertyNames but
+   * the returned array doesn't contain the names of properties from
+   * prototype objects.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetOwnPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context);
+
+  /**
+   * Returns an array containing the names of the filtered properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context, PropertyFilter filter);
+
+  /**
+   * Get the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  Local<Value> GetPrototype();
+
+  /**
+   * Set the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  V8_DEPRECATED("Use maybe version", bool SetPrototype(Local<Value> prototype));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetPrototype(Local<Context> context,
+                                                 Local<Value> prototype);
+
+  /**
+   * Finds an instance of the given function template in the prototype
+   * chain.
+   */
+  Local<Object> FindInstanceInPrototypeChain(Local<FunctionTemplate> tmpl);
+
+  /**
+   * Call builtin Object.prototype.toString on this object.
+   * This is different from Value::ToString() that may call
+   * user-defined toString function. This one does not.
+   */
+  V8_DEPRECATED("Use maybe version", Local<String> ObjectProtoToString());
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ObjectProtoToString(
+      Local<Context> context);
+
+  /**
+   * Returns the name of the function invoked as a constructor for this object.
+   */
+  Local<String> GetConstructorName();
+
+  /**
+   * Sets the integrity level of the object.
+   */
+  Maybe<bool> SetIntegrityLevel(Local<Context> context, IntegrityLevel level);
+
+  /** Gets the number of internal fields for this Object. */
+  int InternalFieldCount();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static int InternalFieldCount(
+      const PersistentBase<Object>& object) {
+    return object.val_->InternalFieldCount();
+  }
+
+  /** Gets the value from an internal field. */
+  V8_INLINE Local<Value> GetInternalField(int index);
+
+  /** Sets the value in an internal field. */
+  void SetInternalField(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from an internal field. This field
+   * must have been set by SetAlignedPointerInInternalField, everything else
+   * leads to undefined behavior.
+   */
+  V8_INLINE void* GetAlignedPointerFromInternalField(int index);
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static void* GetAlignedPointerFromInternalField(
+      const PersistentBase<Object>& object, int index) {
+    return object.val_->GetAlignedPointerFromInternalField(index);
+  }
+
+  /**
+   * Sets a 2-byte-aligned native pointer in an internal field. To retrieve such
+   * a field, GetAlignedPointerFromInternalField must be used, everything else
+   * leads to undefined behavior.
+   */
+  void SetAlignedPointerInInternalField(int index, void* value);
+  void SetAlignedPointerInInternalFields(int argc, int indices[],
+                                         void* values[]);
+
+  // Testers for local properties.
+  V8_DEPRECATED("Use maybe version", bool HasOwnProperty(Local<String> key));
+
+  /**
+   * HasOwnProperty() is like JavaScript's Object.prototype.hasOwnProperty().
+   *
+   * See also v8::Object::Has() and v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   Local<Name> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedProperty(Local<String> key));
+  /**
+   * Use HasRealNamedProperty() if you want to check if an object has an own
+   * property without causing side effects, i.e., without calling interceptors.
+   *
+   * This function is similar to v8::Object::HasOwnProperty(), but it does not
+   * call interceptors.
+   *
+   * \note Consider using non-masking interceptors, i.e., the interceptors are
+   * not called if the receiver has the real named property. See
+   * `v8::PropertyHandlerFlags::kNonMasking`.
+   *
+   * See also v8::Object::Has().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedProperty(Local<Context> context,
+                                                         Local<Name> key);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealIndexedProperty(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealIndexedProperty(
+      Local<Context> context, uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedCallbackProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedCallbackProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Local<Value> GetRealNamedPropertyInPrototypeChain(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedPropertyInPrototypeChain(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property in the prototype chain,
+   * which can be None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Maybe<PropertyAttribute> GetRealNamedPropertyAttributesInPrototypeChain(
+          Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute>
+  GetRealNamedPropertyAttributesInPrototypeChain(Local<Context> context,
+                                                 Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located on the object or
+   * in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetRealNamedProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property which can be
+   * None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+                    Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+      Local<Context> context, Local<Name> key);
+
+  /** Tests for a named lookup interceptor.*/
+  bool HasNamedLookupInterceptor();
+
+  /** Tests for an index lookup interceptor.*/
+  bool HasIndexedLookupInterceptor();
+
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses a hidden property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  /**
+   * Clone this object with a fast but shallow copy.  Values will point
+   * to the same values as the original object.
+   */
+  // TODO(dcarney): take an isolate and optionally bail out?
+  Local<Object> Clone();
+
+  /**
+   * Returns the context in which the object was created.
+   */
+  Local<Context> CreationContext();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static Local<Context> CreationContext(
+      const PersistentBase<Object>& object) {
+    return object.val_->CreationContext();
+  }
+
+  /**
+   * Checks whether a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * When an Object is callable this method returns true.
+   */
+  bool IsCallable();
+
+  /**
+   * True if this object is a constructor.
+   */
+  bool IsConstructor();
+
+  /**
+   * Call an Object as a function if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsFunction(Local<Value> recv, int argc,
+                                            Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsFunction(Local<Context> context,
+                                                         Local<Value> recv,
+                                                         int argc,
+                                                         Local<Value> argv[]);
+
+  /**
+   * Call an Object as a constructor if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * Note: This method behaves like the Function::NewInstance method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsConstructor(int argc, Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsConstructor(
+      Local<Context> context, int argc, Local<Value> argv[]);
+
+  /**
+   * Return the isolate to which the Object belongs to.
+   */
+  V8_DEPRECATE_SOON("Keep track of isolate correctly", Isolate* GetIsolate());
+
+  static Local<Object> New(Isolate* isolate);
+
+  V8_INLINE static Object* Cast(Value* obj);
+
+ private:
+  Object();
+  static void CheckCast(Value* obj);
+  Local<Value> SlowGetInternalField(int index);
+  void* SlowGetAlignedPointerFromInternalField(int index);
+};
+
+
+/**
+ * An instance of the built-in array constructor (ECMA-262, 15.4.2).
+ */
+class V8_EXPORT Array : public Object {
+ public:
+  uint32_t Length() const;
+
+  /**
+   * Clones an element at index |index|.  Returns an empty
+   * handle if cloning fails (for any reason).
+   */
+  V8_DEPRECATED("Cloning is not supported.",
+                Local<Object> CloneElementAt(uint32_t index));
+  V8_DEPRECATED("Cloning is not supported.",
+                MaybeLocal<Object> CloneElementAt(Local<Context> context,
+                                                  uint32_t index));
+
+  /**
+   * Creates a JavaScript array with the given length. If the length
+   * is negative the returned array will have length 0.
+   */
+  static Local<Array> New(Isolate* isolate, int length = 0);
+
+  V8_INLINE static Array* Cast(Value* obj);
+ private:
+  Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Map constructor (ECMA-262, 6th Edition, 23.1.1).
+ */
+class V8_EXPORT Map : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Map> Set(Local<Context> context,
+                                            Local<Value> key,
+                                            Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of length Size() * 2, where index N is the Nth key and
+   * index N + 1 is the Nth value.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Map.
+   */
+  static Local<Map> New(Isolate* isolate);
+
+  V8_INLINE static Map* Cast(Value* obj);
+
+ private:
+  Map();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Set constructor (ECMA-262, 6th Edition, 23.2.1).
+ */
+class V8_EXPORT Set : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Set> Add(Local<Context> context,
+                                            Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of the keys in this Set.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Set.
+   */
+  static Local<Set> New(Isolate* isolate);
+
+  V8_INLINE static Set* Cast(Value* obj);
+
+ private:
+  Set();
+  static void CheckCast(Value* obj);
+};
+
+
+template<typename T>
+class ReturnValue {
+ public:
+  template <class S> V8_INLINE ReturnValue(const ReturnValue<S>& that)
+      : value_(that.value_) {
+    TYPE_CHECK(T, S);
+  }
+  // Local setters
+  template <typename S>
+  V8_INLINE V8_DEPRECATE_SOON("Use Global<> instead",
+                              void Set(const Persistent<S>& handle));
+  template <typename S>
+  V8_INLINE void Set(const Global<S>& handle);
+  template <typename S>
+  V8_INLINE void Set(const Local<S> handle);
+  // Fast primitive setters
+  V8_INLINE void Set(bool value);
+  V8_INLINE void Set(double i);
+  V8_INLINE void Set(int32_t i);
+  V8_INLINE void Set(uint32_t i);
+  // Fast JS primitive setters
+  V8_INLINE void SetNull();
+  V8_INLINE void SetUndefined();
+  V8_INLINE void SetEmptyString();
+  // Convenience getter for Isolate
+  V8_INLINE Isolate* GetIsolate() const;
+
+  // Pointer setter: Uncompilable to prevent inadvertent misuse.
+  template <typename S>
+  V8_INLINE void Set(S* whatever);
+
+  // Getter. Creates a new Local<> so it comes with a certain performance
+  // hit. If the ReturnValue was not yet set, this will return the undefined
+  // value.
+  V8_INLINE Local<Value> Get() const;
+
+ private:
+  template<class F> friend class ReturnValue;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  template <class F, class G, class H>
+  friend class PersistentValueMapBase;
+  V8_INLINE void SetInternal(internal::Object* value) { *value_ = value; }
+  V8_INLINE internal::Object* GetDefaultValue();
+  V8_INLINE explicit ReturnValue(internal::Object** slot);
+  internal::Object** value_;
+};
+
+
+/**
+ * The argument information given to function call callbacks.  This
+ * class provides access to information about the context of the call,
+ * including the receiver, the number and values of arguments, and
+ * the holder of the function.
+ */
+template<typename T>
+class FunctionCallbackInfo {
+ public:
+  /** The number of available arguments. */
+  V8_INLINE int Length() const;
+  /** Accessor for the available arguments. */
+  V8_INLINE Local<Value> operator[](int i) const;
+  V8_INLINE V8_DEPRECATED("Use Data() to explicitly pass Callee instead",
+                          Local<Function> Callee() const);
+  /** Returns the receiver. This corresponds to the "this" value. */
+  V8_INLINE Local<Object> This() const;
+  /**
+   * If the callback was created without a Signature, this is the same
+   * value as This(). If there is a signature, and the signature didn't match
+   * This() but one of its hidden prototypes, this will be the respective
+   * hidden prototype.
+   *
+   * Note that this is not the prototype of This() on which the accessor
+   * referencing this callback was found (which in V8 internally is often
+   * referred to as holder [sic]).
+   */
+  V8_INLINE Local<Object> Holder() const;
+  /** For construct calls, this returns the "new.target" value. */
+  V8_INLINE Local<Value> NewTarget() const;
+  /** Indicates whether this is a regular call or a construct call. */
+  V8_INLINE bool IsConstructCall() const;
+  /** The data argument specified when creating the callback. */
+  V8_INLINE Local<Value> Data() const;
+  /** The current Isolate. */
+  V8_INLINE Isolate* GetIsolate() const;
+  /** The ReturnValue for the call. */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 8;
+
+ protected:
+  friend class internal::FunctionCallbackArguments;
+  friend class internal::CustomArguments<FunctionCallbackInfo>;
+  friend class debug::ConsoleCallArguments;
+  static const int kHolderIndex = 0;
+  static const int kIsolateIndex = 1;
+  static const int kReturnValueDefaultValueIndex = 2;
+  static const int kReturnValueIndex = 3;
+  static const int kDataIndex = 4;
+  static const int kCalleeIndex = 5;
+  static const int kContextSaveIndex = 6;
+  static const int kNewTargetIndex = 7;
+
+  V8_INLINE FunctionCallbackInfo(internal::Object** implicit_args,
+                                 internal::Object** values, int length);
+  internal::Object** implicit_args_;
+  internal::Object** values_;
+  int length_;
+};
+
+
+/**
+ * The information passed to a property callback about the context
+ * of the property access.
+ */
+template<typename T>
+class PropertyCallbackInfo {
+ public:
+  /**
+   * \return The isolate of the property access.
+   */
+  V8_INLINE Isolate* GetIsolate() const;
+
+  /**
+   * \return The data set in the configuration, i.e., in
+   * `NamedPropertyHandlerConfiguration` or
+   * `IndexedPropertyHandlerConfiguration.`
+   */
+  V8_INLINE Local<Value> Data() const;
+
+  /**
+   * \return The receiver. In many cases, this is the object on which the
+   * property access was intercepted. When using
+   * `Reflect.get`, `Function.prototype.call`, or similar functions, it is the
+   * object passed in as receiver or thisArg.
+   *
+   * \code
+   *  void GetterCallback(Local<Name> name,
+   *                      const v8::PropertyCallbackInfo<v8::Value>& info) {
+   *     auto context = info.GetIsolate()->GetCurrentContext();
+   *
+   *     v8::Local<v8::Value> a_this =
+   *         info.This()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *     v8::Local<v8::Value> a_holder =
+   *         info.Holder()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *
+   *    CHECK(v8_str("r")->Equals(context, a_this).FromJust());
+   *    CHECK(v8_str("obj")->Equals(context, a_holder).FromJust());
+   *
+   *    info.GetReturnValue().Set(name);
+   *  }
+   *
+   *  v8::Local<v8::FunctionTemplate> templ =
+   *  v8::FunctionTemplate::New(isolate);
+   *  templ->InstanceTemplate()->SetHandler(
+   *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+   *  LocalContext env;
+   *  env->Global()
+   *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+   *                                           .ToLocalChecked()
+   *                                           ->NewInstance(env.local())
+   *                                           .ToLocalChecked())
+   *      .FromJust();
+   *
+   *  CompileRun("obj.a = 'obj'; var r = {a: 'r'}; Reflect.get(obj, 'x', r)");
+   * \endcode
+   */
+  V8_INLINE Local<Object> This() const;
+
+  /**
+   * \return The object in the prototype chain of the receiver that has the
+   * interceptor. Suppose you have `x` and its prototype is `y`, and `y`
+   * has an interceptor. Then `info.This()` is `x` and `info.Holder()` is `y`.
+   * The Holder() could be a hidden object (the global object, rather
+   * than the global proxy).
+   *
+   * \note For security reasons, do not pass the object back into the runtime.
+   */
+  V8_INLINE Local<Object> Holder() const;
+
+  /**
+   * \return The return value of the callback.
+   * Can be changed by calling Set().
+   * \code
+   * info.GetReturnValue().Set(...)
+   * \endcode
+   *
+   */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+
+  /**
+   * \return True if the intercepted function should throw if an error occurs.
+   * Usually, `true` corresponds to `'use strict'`.
+   *
+   * \note Always `false` when intercepting `Reflect.set()`
+   * independent of the language mode.
+   */
+  V8_INLINE bool ShouldThrowOnError() const;
+
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 7;
+
+ protected:
+  friend class MacroAssembler;
+  friend class internal::PropertyCallbackArguments;
+  friend class internal::CustomArguments<PropertyCallbackInfo>;
+  static const int kShouldThrowOnErrorIndex = 0;
+  static const int kHolderIndex = 1;
+  static const int kIsolateIndex = 2;
+  static const int kReturnValueDefaultValueIndex = 3;
+  static const int kReturnValueIndex = 4;
+  static const int kDataIndex = 5;
+  static const int kThisIndex = 6;
+
+  V8_INLINE PropertyCallbackInfo(internal::Object** args) : args_(args) {}
+  internal::Object** args_;
+};
+
+
+typedef void (*FunctionCallback)(const FunctionCallbackInfo<Value>& info);
+
+enum class ConstructorBehavior { kThrow, kAllow };
+
+/**
+ * A JavaScript function object (ECMA-262, 15.3).
+ */
+class V8_EXPORT Function : public Object {
+ public:
+  /**
+   * Create a function in the current execution context
+   * for a given FunctionCallback.
+   */
+  static MaybeLocal<Function> New(
+      Local<Context> context, FunctionCallback callback,
+      Local<Value> data = Local<Value>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Function> New(Isolate* isolate, FunctionCallback callback,
+                          Local<Value> data = Local<Value>(), int length = 0));
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Object> NewInstance(int argc, Local<Value> argv[]) const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context, int argc, Local<Value> argv[]) const;
+
+  V8_DEPRECATED("Use maybe version", Local<Object> NewInstance() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context) const {
+    return NewInstance(context, 0, nullptr);
+  }
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Value> Call(Local<Value> recv, int argc,
+                                      Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Call(Local<Context> context,
+                                               Local<Value> recv, int argc,
+                                               Local<Value> argv[]);
+
+  void SetName(Local<String> name);
+  Local<Value> GetName() const;
+
+  /**
+   * Name inferred from variable or property assignment of this function.
+   * Used to facilitate debugging and profiling of JavaScript code written
+   * in an OO style, where many functions are anonymous but are assigned
+   * to object properties.
+   */
+  Local<Value> GetInferredName() const;
+
+  /**
+   * displayName if it is set, otherwise name if it is configured, otherwise
+   * function name, otherwise inferred name.
+   */
+  Local<Value> GetDebugName() const;
+
+  /**
+   * User-defined name assigned to the "displayName" property of this function.
+   * Used to facilitate debugging and profiling of JavaScript code.
+   */
+  Local<Value> GetDisplayName() const;
+
+  /**
+   * Returns zero based line number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptLineNumber() const;
+  /**
+   * Returns zero based column number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptColumnNumber() const;
+
+  /**
+   * Tells whether this function is builtin.
+   */
+  V8_DEPRECATED("this should no longer be used.", bool IsBuiltin() const);
+
+  /**
+   * Returns scriptId.
+   */
+  int ScriptId() const;
+
+  /**
+   * Returns the original function if this function is bound, else returns
+   * v8::Undefined.
+   */
+  Local<Value> GetBoundFunction() const;
+
+  ScriptOrigin GetScriptOrigin() const;
+  V8_INLINE static Function* Cast(Value* obj);
+  static const int kLineOffsetNotFound;
+
+ private:
+  Function();
+  static void CheckCast(Value* obj);
+};
+
+#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
+#endif
+
+/**
+ * An instance of the built-in Promise constructor (ES6 draft).
+ */
+class V8_EXPORT Promise : public Object {
+ public:
+  /**
+   * State of the promise. Each value corresponds to one of the possible values
+   * of the [[PromiseState]] field.
+   */
+  enum PromiseState { kPending, kFulfilled, kRejected };
+
+  class V8_EXPORT Resolver : public Object {
+   public:
+    /**
+     * Create a new resolver, along with an associated promise in pending state.
+     */
+    static V8_DEPRECATE_SOON("Use maybe version",
+                             Local<Resolver> New(Isolate* isolate));
+    static V8_WARN_UNUSED_RESULT MaybeLocal<Resolver> New(
+        Local<Context> context);
+
+    /**
+     * Extract the associated promise.
+     */
+    Local<Promise> GetPromise();
+
+    /**
+     * Resolve/reject the associated promise with a given value.
+     * Ignored if the promise is no longer pending.
+     */
+    V8_DEPRECATE_SOON("Use maybe version", void Resolve(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Resolve(Local<Context> context,
+                                              Local<Value> value);
+
+    V8_DEPRECATE_SOON("Use maybe version", void Reject(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Reject(Local<Context> context,
+                                             Local<Value> value);
+
+    V8_INLINE static Resolver* Cast(Value* obj);
+
+   private:
+    Resolver();
+    static void CheckCast(Value* obj);
+  };
+
+  /**
+   * Register a resolution/rejection handler with a promise.
+   * The handler is given the respective resolution/rejection value as
+   * an argument. If the promise is already resolved/rejected, the handler is
+   * invoked at the end of turn.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Catch(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Catch(Local<Context> context,
+                                                  Local<Function> handler);
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Then(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
+                                                 Local<Function> handler);
+
+  /**
+   * Returns true if the promise has at least one derived promise, and
+   * therefore resolve/reject handlers (including default handler).
+   */
+  bool HasHandler();
+
+  /**
+   * Returns the content of the [[PromiseResult]] field. The Promise must not
+   * be pending.
+   */
+  Local<Value> Result();
+
+  /**
+   * Returns the value of the [[PromiseState]] field.
+   */
+  PromiseState State();
+
+  V8_INLINE static Promise* Cast(Value* obj);
+
+  static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
+
+ private:
+  Promise();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of a Property Descriptor, see Ecma-262 6.2.4.
+ *
+ * Properties in a descriptor are present or absent. If you do not set
+ * `enumerable`, `configurable`, and `writable`, they are absent. If `value`,
+ * `get`, or `set` are absent, but you must specify them in the constructor, use
+ * empty handles.
+ *
+ * Accessors `get` and `set` must be callable or undefined if they are present.
+ *
+ * \note Only query properties if they are present, i.e., call `x()` only if
+ * `has_x()` returns true.
+ *
+ * \code
+ * // var desc = {writable: false}
+ * v8::PropertyDescriptor d(Local<Value>()), false);
+ * d.value(); // error, value not set
+ * if (d.has_writable()) {
+ *   d.writable(); // false
+ * }
+ *
+ * // var desc = {value: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate));
+ *
+ * // var desc = {get: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate), Local<Value>()));
+ * \endcode
+ */
+class V8_EXPORT PropertyDescriptor {
+ public:
+  // GenericDescriptor
+  PropertyDescriptor();
+
+  // DataDescriptor
+  PropertyDescriptor(Local<Value> value);
+
+  // DataDescriptor with writable property
+  PropertyDescriptor(Local<Value> value, bool writable);
+
+  // AccessorDescriptor
+  PropertyDescriptor(Local<Value> get, Local<Value> set);
+
+  ~PropertyDescriptor();
+
+  Local<Value> value() const;
+  bool has_value() const;
+
+  Local<Value> get() const;
+  bool has_get() const;
+  Local<Value> set() const;
+  bool has_set() const;
+
+  void set_enumerable(bool enumerable);
+  bool enumerable() const;
+  bool has_enumerable() const;
+
+  void set_configurable(bool configurable);
+  bool configurable() const;
+  bool has_configurable() const;
+
+  bool writable() const;
+  bool has_writable() const;
+
+  struct PrivateData;
+  PrivateData* get_private() const { return private_; }
+
+  PropertyDescriptor(const PropertyDescriptor&) = delete;
+  void operator=(const PropertyDescriptor&) = delete;
+
+ private:
+  PrivateData* private_;
+};
+
+/**
+ * An instance of the built-in Proxy constructor (ECMA-262, 6th Edition,
+ * 26.2.1).
+ */
+class V8_EXPORT Proxy : public Object {
+ public:
+  Local<Object> GetTarget();
+  Local<Value> GetHandler();
+  bool IsRevoked();
+  void Revoke();
+
+  /**
+   * Creates a new Proxy for the target object.
+   */
+  static MaybeLocal<Proxy> New(Local<Context> context,
+                               Local<Object> local_target,
+                               Local<Object> local_handler);
+
+  V8_INLINE static Proxy* Cast(Value* obj);
+
+ private:
+  Proxy();
+  static void CheckCast(Value* obj);
+};
+
+// TODO(mtrofin): rename WasmCompiledModule to WasmModuleObject, for
+// consistency with internal APIs.
+class V8_EXPORT WasmCompiledModule : public Object {
+ public:
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> SerializedModule;
+  // A buffer that is owned by the caller.
+  typedef std::pair<const uint8_t*, size_t> CallerOwnedBuffer;
+
+  // An opaque, native heap object for transferring wasm modules. It
+  // supports move semantics, and does not support copy semantics.
+  class TransferrableModule final {
+   public:
+    TransferrableModule(TransferrableModule&& src) = default;
+    TransferrableModule(const TransferrableModule& src) = delete;
+
+    TransferrableModule& operator=(TransferrableModule&& src) = default;
+    TransferrableModule& operator=(const TransferrableModule& src) = delete;
+
+   private:
+    typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> OwnedBuffer;
+    friend class WasmCompiledModule;
+    TransferrableModule(OwnedBuffer&& code, OwnedBuffer&& bytes)
+        : compiled_code(std::move(code)), wire_bytes(std::move(bytes)) {}
+
+    OwnedBuffer compiled_code = {nullptr, 0};
+    OwnedBuffer wire_bytes = {nullptr, 0};
+  };
+
+  // Get an in-memory, non-persistable, and context-independent (meaning,
+  // suitable for transfer to another Isolate and Context) representation
+  // of this wasm compiled module.
+  TransferrableModule GetTransferrableModule();
+
+  // Efficiently re-create a WasmCompiledModule, without recompiling, from
+  // a TransferrableModule.
+  static MaybeLocal<WasmCompiledModule> FromTransferrableModule(
+      Isolate* isolate, const TransferrableModule&);
+
+  // Get the wasm-encoded bytes that were used to compile this module.
+  Local<String> GetWasmWireBytes();
+
+  // Serialize the compiled module. The serialized data does not include the
+  // uncompiled bytes.
+  SerializedModule Serialize();
+
+  // If possible, deserialize the module, otherwise compile it from the provided
+  // uncompiled bytes.
+  static MaybeLocal<WasmCompiledModule> DeserializeOrCompile(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  V8_INLINE static WasmCompiledModule* Cast(Value* obj);
+
+ private:
+  // TODO(ahaas): please remove the friend once streamed compilation is
+  // implemented
+  friend class WasmModuleObjectBuilder;
+
+  static MaybeLocal<WasmCompiledModule> Deserialize(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  static MaybeLocal<WasmCompiledModule> Compile(Isolate* isolate,
+                                                const uint8_t* start,
+                                                size_t length);
+  static CallerOwnedBuffer AsCallerOwned(
+      const TransferrableModule::OwnedBuffer& buff) {
+    return {buff.first.get(), buff.second};
+  }
+
+  WasmCompiledModule();
+  static void CheckCast(Value* obj);
+};
+
+class V8_EXPORT WasmModuleObjectBuilder final {
+ public:
+  WasmModuleObjectBuilder(Isolate* isolate) : isolate_(isolate) {}
+  // The buffer passed into OnBytesReceived is owned by the caller.
+  void OnBytesReceived(const uint8_t*, size_t size);
+  MaybeLocal<WasmCompiledModule> Finish();
+
+ private:
+  Isolate* isolate_ = nullptr;
+  // TODO(ahaas): We probably need none of this below here once streamed
+  // compilation is implemented.
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> Buffer;
+
+  // Disable copy semantics *in this implementation*. We can choose to
+  // relax this, albeit it's not clear why.
+  WasmModuleObjectBuilder(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder(WasmModuleObjectBuilder&&) = default;
+  WasmModuleObjectBuilder& operator=(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder& operator=(WasmModuleObjectBuilder&&) = default;
+
+  std::vector<Buffer> received_buffers_;
+  size_t total_size_ = 0;
+};
+
+#ifndef V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+enum class ArrayBufferCreationMode { kInternalized, kExternalized };
+
+
+/**
+ * An instance of the built-in ArrayBuffer constructor (ES6 draft 15.13.5).
+ */
+class V8_EXPORT ArrayBuffer : public Object {
+ public:
+  /**
+   * A thread-safe allocator that V8 uses to allocate |ArrayBuffer|'s memory.
+   * The allocator is a global V8 setting. It has to be set via
+   * Isolate::CreateParams.
+   *
+   * Memory allocated through this allocator by V8 is accounted for as external
+   * memory by V8. Note that V8 keeps track of the memory for all internalized
+   * |ArrayBuffer|s. Responsibility for tracking external memory (using
+   * Isolate::AdjustAmountOfExternalAllocatedMemory) is handed over to the
+   * embedder upon externalization and taken over upon internalization (creating
+   * an internalized buffer from an existing buffer).
+   *
+   * Note that it is unsafe to call back into V8 from any of the allocator
+   * functions.
+   */
+  class V8_EXPORT Allocator { // NOLINT
+   public:
+    virtual ~Allocator() {}
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory should be initialized to zeroes.
+     */
+    virtual void* Allocate(size_t length) = 0;
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory does not have to be initialized.
+     */
+    virtual void* AllocateUninitialized(size_t length) = 0;
+
+    /**
+     * Reserved |length| bytes, but do not commit the memory. Must call
+     * |SetProtection| to make memory accessible.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void* Reserve(size_t length);
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate|.
+     */
+    virtual void Free(void* data, size_t length) = 0;
+
+    enum class AllocationMode { kNormal, kReservation };
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate| or
+     * |Reserve|, depending on |mode|.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void Free(void* data, size_t length, AllocationMode mode);
+
+    enum class Protection { kNoAccess, kReadWrite };
+
+    /**
+     * Change the protection on a region of memory.
+     *
+     * On platforms that make a distinction between reserving and committing
+     * memory, changing the protection to kReadWrite must also ensure the memory
+     * is committed.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void SetProtection(void* data, size_t length,
+                               Protection protection);
+
+    /**
+     * malloc/free based convenience allocator.
+     *
+     * Caller takes ownership, i.e. the returned object needs to be freed using
+     * |delete allocator| once it is no longer in use.
+     */
+    static Allocator* NewDefaultAllocator();
+  };
+
+  /**
+   * The contents of an |ArrayBuffer|. Externalization of |ArrayBuffer|
+   * returns an instance of this class, populated, with a pointer to data
+   * and byte length.
+   *
+   * The Data pointer of ArrayBuffer::Contents is always allocated with
+   * Allocator::Allocate that is set via Isolate::CreateParams.
+   */
+  class V8_EXPORT Contents { // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class ArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new ArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created ArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<ArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new ArrayBuffer over an existing memory block.
+   * The created array buffer is by default immediately in externalized state.
+   * In externalized state, the memory block will not be reclaimed when a
+   * created ArrayBuffer is garbage-collected.
+   * In internalized state, the memory block will be released using
+   * |Allocator::Free| once all ArrayBuffers referencing it are collected by
+   * the garbage collector.
+   */
+  static Local<ArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if ArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this ArrayBuffer may be neutered.
+   */
+  bool IsNeuterable() const;
+
+  /**
+   * Neuters this ArrayBuffer and all its views (typed arrays).
+   * Neutering sets the byte length of the buffer and all typed arrays to zero,
+   * preventing JavaScript from ever accessing underlying backing store.
+   * ArrayBuffer should have been externalized and must be neuterable.
+   */
+  void Neuter();
+
+  /**
+   * Make this ArrayBuffer external. The pointer to underlying memory block
+   * and byte length are returned as |Contents| structure. After ArrayBuffer
+   * had been externalized, it does no longer own the memory block. The caller
+   * should take steps to free memory when it is no longer needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * that has been set via Isolate::CreateParams.
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer gets garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|.
+   */
+  Contents GetContents();
+
+  V8_INLINE static ArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+#ifndef V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+/**
+ * A base class for an instance of one of "views" over ArrayBuffer,
+ * including TypedArrays and DataView (ES6 draft 15.13).
+ */
+class V8_EXPORT ArrayBufferView : public Object {
+ public:
+  /**
+   * Returns underlying ArrayBuffer.
+   */
+  Local<ArrayBuffer> Buffer();
+  /**
+   * Byte offset in |Buffer|.
+   */
+  size_t ByteOffset();
+  /**
+   * Size of a view in bytes.
+   */
+  size_t ByteLength();
+
+  /**
+   * Copy the contents of the ArrayBufferView's buffer to an embedder defined
+   * memory without additional overhead that calling ArrayBufferView::Buffer
+   * might incur.
+   *
+   * Will write at most min(|byte_length|, ByteLength) bytes starting at
+   * ByteOffset of the underlying buffer to the memory starting at |dest|.
+   * Returns the number of bytes actually written.
+   */
+  size_t CopyContents(void* dest, size_t byte_length);
+
+  /**
+   * Returns true if ArrayBufferView's backing ArrayBuffer has already been
+   * allocated.
+   */
+  bool HasBuffer() const;
+
+  V8_INLINE static ArrayBufferView* Cast(Value* obj);
+
+  static const int kInternalFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBufferView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A base class for an instance of TypedArray series of constructors
+ * (ES6 draft 15.13.6).
+ */
+class V8_EXPORT TypedArray : public ArrayBufferView {
+ public:
+  /**
+   * Number of elements in this typed array
+   * (e.g. for Int16Array, |ByteLength|/2).
+   */
+  size_t Length();
+
+  V8_INLINE static TypedArray* Cast(Value* obj);
+
+ private:
+  TypedArray();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8Array : public TypedArray {
+ public:
+  static Local<Uint8Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Uint8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Uint8Array* Cast(Value* obj);
+
+ private:
+  Uint8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8ClampedArray constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8ClampedArray : public TypedArray {
+ public:
+  static Local<Uint8ClampedArray> New(Local<ArrayBuffer> array_buffer,
+                                      size_t byte_offset, size_t length);
+  static Local<Uint8ClampedArray> New(
+      Local<SharedArrayBuffer> shared_array_buffer, size_t byte_offset,
+      size_t length);
+  V8_INLINE static Uint8ClampedArray* Cast(Value* obj);
+
+ private:
+  Uint8ClampedArray();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of Int8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int8Array : public TypedArray {
+ public:
+  static Local<Int8Array> New(Local<ArrayBuffer> array_buffer,
+                              size_t byte_offset, size_t length);
+  static Local<Int8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                              size_t byte_offset, size_t length);
+  V8_INLINE static Int8Array* Cast(Value* obj);
+
+ private:
+  Int8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint16Array : public TypedArray {
+ public:
+  static Local<Uint16Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint16Array* Cast(Value* obj);
+
+ private:
+  Uint16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int16Array : public TypedArray {
+ public:
+  static Local<Int16Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int16Array* Cast(Value* obj);
+
+ private:
+  Int16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint32Array : public TypedArray {
+ public:
+  static Local<Uint32Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint32Array* Cast(Value* obj);
+
+ private:
+  Uint32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int32Array : public TypedArray {
+ public:
+  static Local<Int32Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int32Array* Cast(Value* obj);
+
+ private:
+  Int32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float32Array : public TypedArray {
+ public:
+  static Local<Float32Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float32Array* Cast(Value* obj);
+
+ private:
+  Float32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float64Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float64Array : public TypedArray {
+ public:
+  static Local<Float64Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float64Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float64Array* Cast(Value* obj);
+
+ private:
+  Float64Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of DataView constructor (ES6 draft 15.13.7).
+ */
+class V8_EXPORT DataView : public ArrayBufferView {
+ public:
+  static Local<DataView> New(Local<ArrayBuffer> array_buffer,
+                             size_t byte_offset, size_t length);
+  static Local<DataView> New(Local<SharedArrayBuffer> shared_array_buffer,
+                             size_t byte_offset, size_t length);
+  V8_INLINE static DataView* Cast(Value* obj);
+
+ private:
+  DataView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in SharedArrayBuffer constructor.
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedArrayBuffer : public Object {
+ public:
+  /**
+   * The contents of an |SharedArrayBuffer|. Externalization of
+   * |SharedArrayBuffer| returns an instance of this class, populated, with a
+   * pointer to data and byte length.
+   *
+   * The Data pointer of SharedArrayBuffer::Contents is always allocated with
+   * |ArrayBuffer::Allocator::Allocate| by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   * This API is experimental and may change significantly.
+   */
+  class V8_EXPORT Contents {  // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class SharedArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new SharedArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created SharedArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<SharedArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new SharedArrayBuffer over an existing memory block.  The created
+   * array buffer is immediately in externalized state unless otherwise
+   * specified. The memory block will not be reclaimed when a created
+   * SharedArrayBuffer is garbage-collected.
+   */
+  static Local<SharedArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if SharedArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Make this SharedArrayBuffer external. The pointer to underlying memory
+   * block and byte length are returned as |Contents| structure. After
+   * SharedArrayBuffer had been externalized, it does no longer own the memory
+   * block. The caller should take steps to free memory when it is no longer
+   * needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer became garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   */
+  Contents GetContents();
+
+  V8_INLINE static SharedArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  SharedArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Date constructor (ECMA-262, 15.9).
+ */
+class V8_EXPORT Date : public Object {
+ public:
+  static V8_DEPRECATE_SOON("Use maybe version.",
+                           Local<Value> New(Isolate* isolate, double time));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> New(Local<Context> context,
+                                                     double time);
+
+  /**
+   * A specialization of Value::NumberValue that is more efficient
+   * because we know the structure of this object.
+   */
+  double ValueOf() const;
+
+  V8_INLINE static Date* Cast(Value* obj);
+
+  /**
+   * Notification that the embedder has changed the time zone,
+   * daylight savings time, or other date / time configuration
+   * parameters.  V8 keeps a cache of various values used for
+   * date / time computation.  This notification will reset
+   * those cached values for the current context so that date /
+   * time configuration changes would be reflected in the Date
+   * object.
+   *
+   * This API should not be called more than needed as it will
+   * negatively impact the performance of date operations.
+   */
+  static void DateTimeConfigurationChangeNotification(Isolate* isolate);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Number object (ECMA-262, 4.3.21).
+ */
+class V8_EXPORT NumberObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, double value);
+
+  double ValueOf() const;
+
+  V8_INLINE static NumberObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Boolean object (ECMA-262, 4.3.15).
+ */
+class V8_EXPORT BooleanObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, bool value);
+  V8_DEPRECATED("Pass an isolate", static Local<Value> New(bool value));
+
+  bool ValueOf() const;
+
+  V8_INLINE static BooleanObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A String object (ECMA-262, 4.3.18).
+ */
+class V8_EXPORT StringObject : public Object {
+ public:
+  static Local<Value> New(Local<String> value);
+
+  Local<String> ValueOf() const;
+
+  V8_INLINE static StringObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Symbol object (ECMA-262 edition 6).
+ */
+class V8_EXPORT SymbolObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, Local<Symbol> value);
+
+  Local<Symbol> ValueOf() const;
+
+  V8_INLINE static SymbolObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in RegExp constructor (ECMA-262, 15.10).
+ */
+class V8_EXPORT RegExp : public Object {
+ public:
+  /**
+   * Regular expression flag bits. They can be or'ed to enable a set
+   * of flags.
+   */
+  enum Flags {
+    kNone = 0,
+    kGlobal = 1 << 0,
+    kIgnoreCase = 1 << 1,
+    kMultiline = 1 << 2,
+    kSticky = 1 << 3,
+    kUnicode = 1 << 4,
+    kDotAll = 1 << 5,
+  };
+
+  /**
+   * Creates a regular expression from the given pattern string and
+   * the flags bit field. May throw a JavaScript exception as
+   * described in ECMA-262, 15.10.4.1.
+   *
+   * For example,
+   *   RegExp::New(v8::String::New("foo"),
+   *               static_cast<RegExp::Flags>(kGlobal | kMultiline))
+   * is equivalent to evaluating "/foo/gm".
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<RegExp> New(Local<String> pattern,
+                                             Flags flags));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<RegExp> New(Local<Context> context,
+                                                      Local<String> pattern,
+                                                      Flags flags);
+
+  /**
+   * Returns the value of the source property: a string representing
+   * the regular expression.
+   */
+  Local<String> GetSource() const;
+
+  /**
+   * Returns the flags bit field.
+   */
+  Flags GetFlags() const;
+
+  V8_INLINE static RegExp* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A JavaScript value that wraps a C++ void*. This type of value is mainly used
+ * to associate C++ data structures with JavaScript objects.
+ */
+class V8_EXPORT External : public Value {
+ public:
+  static Local<External> New(Isolate* isolate, void* value);
+  V8_INLINE static External* Cast(Value* obj);
+  void* Value() const;
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+#define V8_INTRINSICS_LIST(F)                    \
+  F(ArrayProto_entries, array_entries_iterator)  \
+  F(ArrayProto_forEach, array_for_each_iterator) \
+  F(ArrayProto_keys, array_keys_iterator)        \
+  F(ArrayProto_values, array_values_iterator)    \
+  F(IteratorPrototype, initial_iterator_prototype)
+
+enum Intrinsic {
+#define V8_DECL_INTRINSIC(name, iname) k##name,
+  V8_INTRINSICS_LIST(V8_DECL_INTRINSIC)
+#undef V8_DECL_INTRINSIC
+};
+
+
+// --- Templates ---
+
+
+/**
+ * The superclass of object and function templates.
+ */
+class V8_EXPORT Template : public Data {
+ public:
+  /**
+   * Adds a property to each instance created by this template.
+   *
+   * The property must be defined either as a primitive value, or a template.
+   */
+  void Set(Local<Name> name, Local<Data> value,
+           PropertyAttribute attributes = None);
+  void SetPrivate(Local<Private> name, Local<Data> value,
+                  PropertyAttribute attributes = None);
+  V8_INLINE void Set(Isolate* isolate, const char* name, Local<Data> value);
+
+  void SetAccessorProperty(
+     Local<Name> name,
+     Local<FunctionTemplate> getter = Local<FunctionTemplate>(),
+     Local<FunctionTemplate> setter = Local<FunctionTemplate>(),
+     PropertyAttribute attribute = None,
+     AccessControl settings = DEFAULT);
+
+  /**
+   * Whenever the property with the given name is accessed on objects
+   * created from this Template the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetNativeDataProperty(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+  void SetNativeDataProperty(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+
+  /**
+   * Like SetNativeDataProperty, but V8 will replace the native data property
+   * with a real data property on first access.
+   */
+  void SetLazyDataProperty(Local<Name> name, AccessorNameGetterCallback getter,
+                           Local<Value> data = Local<Value>(),
+                           PropertyAttribute attribute = None);
+
+  /**
+   * During template instantiation, sets the value with the intrinsic property
+   * from the correct context.
+   */
+  void SetIntrinsicDataProperty(Local<Name> name, Intrinsic intrinsic,
+                                PropertyAttribute attribute = None);
+
+ private:
+  Template();
+
+  friend class ObjectTemplate;
+  friend class FunctionTemplate;
+};
+
+
+/**
+ * NamedProperty[Getter|Setter] are used as interceptors on object.
+ * See ObjectTemplate::SetNamedPropertyHandler.
+ */
+typedef void (*NamedPropertyGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns the value if the setter intercepts the request.
+ * Otherwise, returns an empty handle.
+ */
+typedef void (*NamedPropertySetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns a non-empty handle if the interceptor intercepts the request.
+ * The result is an integer encoding property attributes (like v8::None,
+ * v8::DontEnum, etc.)
+ */
+typedef void (*NamedPropertyQueryCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Integer>& info);
+
+
+/**
+ * Returns a non-empty handle if the deleter intercepts the request.
+ * The return value is true if the property could be deleted and false
+ * otherwise.
+ */
+typedef void (*NamedPropertyDeleterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*NamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+
+// TODO(dcarney): Deprecate and remove previous typedefs, and replace
+// GenericNamedPropertyFooCallback with just NamedPropertyFooCallback.
+
+/**
+ * Interceptor for get requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted get request.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict`' mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \code
+ *  void GetterCallback(
+ *    Local<Name> name,
+ *    const v8::PropertyCallbackInfo<v8::Value>& info) {
+ *      info.GetReturnValue().Set(v8_num(42));
+ *  }
+ *
+ *  v8::Local<v8::FunctionTemplate> templ =
+ *      v8::FunctionTemplate::New(isolate);
+ *  templ->InstanceTemplate()->SetHandler(
+ *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+ *  LocalContext env;
+ *  env->Global()
+ *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+ *                                             .ToLocalChecked()
+ *                                             ->NewInstance(env.local())
+ *                                             .ToLocalChecked())
+ *      .FromJust();
+ *  v8::Local<v8::Value> result = CompileRun("obj.a = 17; obj.a");
+ *  CHECK(v8_num(42)->Equals(env.local(), result).FromJust());
+ * \endcode
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyGetterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for set requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the setter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the setter
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param value The value which the property will have if the request
+ * is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertySetterCallback)(
+    Local<Name> property, Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Intercepts all requests that query the attributes of the
+ * property, e.g., getOwnPropertyDescriptor(), propertyIsEnumerable(), and
+ * defineProperty().
+ *
+ * Use `info.GetReturnValue().Set(value)` to set the property attributes. The
+ * value is an interger encoding a `v8::PropertyAttribute`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note Some functions query the property attributes internally, even though
+ * they do not return the attributes. For example, `hasOwnProperty()` can
+ * trigger this interceptor depending on the state of the object.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyQueryCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * Interceptor for delete requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the deleter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)` with a boolean `value`. The `value` is
+ * used as the return value of `delete`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If you need to mimic the behavior of `delete`, i.e., throw in strict
+ * mode instead of returning false, use `info.ShouldThrowOnError()` to determine
+ * if you are in strict mode.
+ *
+ * See also `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyDeleterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*GenericNamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * Interceptor for defineProperty requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the definer successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the definer
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param desc The property descriptor which is used to define the
+ * property if the request is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDefinerCallback)(
+    Local<Name> property, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for getOwnPropertyDescriptor requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted request. The return value must be an object that
+ * can be converted to a PropertyDescriptor, e.g., a `v8::value` returned from
+ * `v8::Object::getOwnPropertyDescriptor`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If GetOwnPropertyDescriptor is intercepted, it will
+ * always return true, i.e., indicate that the property was found.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDescriptorCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyGetterCallback`.
+ */
+typedef void (*IndexedPropertyGetterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertySetterCallback`.
+ */
+typedef void (*IndexedPropertySetterCallback)(
+    uint32_t index,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyQueryCallback`.
+ */
+typedef void (*IndexedPropertyQueryCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDeleterCallback`.
+ */
+typedef void (*IndexedPropertyDeleterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Boolean>& info);
+
+/**
+ * See `v8::GenericNamedPropertyEnumeratorCallback`.
+ */
+typedef void (*IndexedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDefinerCallback`.
+ */
+typedef void (*IndexedPropertyDefinerCallback)(
+    uint32_t index, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDescriptorCallback`.
+ */
+typedef void (*IndexedPropertyDescriptorCallback)(
+    uint32_t index, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Access type specification.
+ */
+enum AccessType {
+  ACCESS_GET,
+  ACCESS_SET,
+  ACCESS_HAS,
+  ACCESS_DELETE,
+  ACCESS_KEYS
+};
+
+
+/**
+ * Returns true if the given context should be allowed to access the given
+ * object.
+ */
+typedef bool (*AccessCheckCallback)(Local<Context> accessing_context,
+                                    Local<Object> accessed_object,
+                                    Local<Value> data);
+
+/**
+ * A FunctionTemplate is used to create functions at runtime. There
+ * can only be one function created from a FunctionTemplate in a
+ * context.  The lifetime of the created function is equal to the
+ * lifetime of the context.  So in case the embedder needs to create
+ * temporary functions that can be collected using Scripts is
+ * preferred.
+ *
+ * Any modification of a FunctionTemplate after first instantiation will trigger
+ * a crash.
+ *
+ * A FunctionTemplate can have properties, these properties are added to the
+ * function object when it is created.
+ *
+ * A FunctionTemplate has a corresponding instance template which is
+ * used to create object instances when the function is used as a
+ * constructor. Properties added to the instance template are added to
+ * each object instance.
+ *
+ * A FunctionTemplate can have a prototype template. The prototype template
+ * is used to create the prototype object of the function.
+ *
+ * The following example shows how to use a FunctionTemplate:
+ *
+ * \code
+ *    v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(isolate);
+ *    t->Set(isolate, "func_property", v8::Number::New(isolate, 1));
+ *
+ *    v8::Local<v8::Template> proto_t = t->PrototypeTemplate();
+ *    proto_t->Set(isolate,
+ *                 "proto_method",
+ *                 v8::FunctionTemplate::New(isolate, InvokeCallback));
+ *    proto_t->Set(isolate, "proto_const", v8::Number::New(isolate, 2));
+ *
+ *    v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
+ *    instance_t->SetAccessor(String::NewFromUtf8(isolate, "instance_accessor"),
+ *                            InstanceAccessorCallback);
+ *    instance_t->SetNamedPropertyHandler(PropertyHandlerCallback);
+ *    instance_t->Set(String::NewFromUtf8(isolate, "instance_property"),
+ *                    Number::New(isolate, 3));
+ *
+ *    v8::Local<v8::Function> function = t->GetFunction();
+ *    v8::Local<v8::Object> instance = function->NewInstance();
+ * \endcode
+ *
+ * Let's use "function" as the JS variable name of the function object
+ * and "instance" for the instance object created above.  The function
+ * and the instance will have the following properties:
+ *
+ * \code
+ *   func_property in function == true;
+ *   function.func_property == 1;
+ *
+ *   function.prototype.proto_method() invokes 'InvokeCallback'
+ *   function.prototype.proto_const == 2;
+ *
+ *   instance instanceof function == true;
+ *   instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   instance.instance_property == 3;
+ * \endcode
+ *
+ * A FunctionTemplate can inherit from another one by calling the
+ * FunctionTemplate::Inherit method.  The following graph illustrates
+ * the semantics of inheritance:
+ *
+ * \code
+ *   FunctionTemplate Parent  -> Parent() . prototype -> { }
+ *     ^                                                  ^
+ *     | Inherit(Parent)                                  | .__proto__
+ *     |                                                  |
+ *   FunctionTemplate Child   -> Child()  . prototype -> { }
+ * \endcode
+ *
+ * A FunctionTemplate 'Child' inherits from 'Parent', the prototype
+ * object of the Child() function has __proto__ pointing to the
+ * Parent() function's prototype object. An instance of the Child
+ * function has all properties on Parent's instance templates.
+ *
+ * Let Parent be the FunctionTemplate initialized in the previous
+ * section and create a Child FunctionTemplate by:
+ *
+ * \code
+ *   Local<FunctionTemplate> parent = t;
+ *   Local<FunctionTemplate> child = FunctionTemplate::New();
+ *   child->Inherit(parent);
+ *
+ *   Local<Function> child_function = child->GetFunction();
+ *   Local<Object> child_instance = child_function->NewInstance();
+ * \endcode
+ *
+ * The Child function and Child instance will have the following
+ * properties:
+ *
+ * \code
+ *   child_func.prototype.__proto__ == function.prototype;
+ *   child_instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   child_instance.instance_property == 3;
+ * \endcode
+ */
+class V8_EXPORT FunctionTemplate : public Template {
+ public:
+  /** Creates a function template.*/
+  static Local<FunctionTemplate> New(
+      Isolate* isolate, FunctionCallback callback = 0,
+      Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<FunctionTemplate> FromSnapshot(Isolate* isolate,
+                                                   size_t index);
+
+  /**
+   * Creates a function template backed/cached by a private property.
+   */
+  static Local<FunctionTemplate> NewWithCache(
+      Isolate* isolate, FunctionCallback callback,
+      Local<Private> cache_property, Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0);
+
+  /** Returns the unique function instance in the current execution context.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Function> GetFunction());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Function> GetFunction(
+      Local<Context> context);
+
+  /**
+   * Similar to Context::NewRemoteContext, this creates an instance that
+   * isn't backed by an actual object.
+   *
+   * The InstanceTemplate of this FunctionTemplate must have access checks with
+   * handlers installed.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewRemoteInstance();
+
+  /**
+   * Set the call-handler callback for a FunctionTemplate.  This
+   * callback is called whenever the function created from this
+   * FunctionTemplate is called.
+   */
+  void SetCallHandler(FunctionCallback callback,
+                      Local<Value> data = Local<Value>());
+
+  /** Set the predefined length property for the FunctionTemplate. */
+  void SetLength(int length);
+
+  /** Get the InstanceTemplate. */
+  Local<ObjectTemplate> InstanceTemplate();
+
+  /**
+   * Causes the function template to inherit from a parent function template.
+   * This means the the function's prototype.__proto__ is set to the parent
+   * function's prototype.
+   **/
+  void Inherit(Local<FunctionTemplate> parent);
+
+  /**
+   * A PrototypeTemplate is the template used to create the prototype object
+   * of the function created by this template.
+   */
+  Local<ObjectTemplate> PrototypeTemplate();
+
+  /**
+   * A PrototypeProviderTemplate is another function template whose prototype
+   * property is used for this template. This is mutually exclusive with setting
+   * a prototype template indirectly by calling PrototypeTemplate() or using
+   * Inherit().
+   **/
+  void SetPrototypeProviderTemplate(Local<FunctionTemplate> prototype_provider);
+
+  /**
+   * Set the class name of the FunctionTemplate.  This is used for
+   * printing objects created with the function created from the
+   * FunctionTemplate as its constructor.
+   */
+  void SetClassName(Local<String> name);
+
+
+  /**
+   * When set to true, no access check will be performed on the receiver of a
+   * function call.  Currently defaults to true, but this is subject to change.
+   */
+  void SetAcceptAnyReceiver(bool value);
+
+  /**
+   * Determines whether the __proto__ accessor ignores instances of
+   * the function template.  If instances of the function template are
+   * ignored, __proto__ skips all instances and instead returns the
+   * next object in the prototype chain.
+   *
+   * Call with a value of true to make the __proto__ accessor ignore
+   * instances of the function template.  Call with a value of false
+   * to make the __proto__ accessor not ignore instances of the
+   * function template.  By default, instances of a function template
+   * are not ignored.
+   */
+  void SetHiddenPrototype(bool value);
+
+  /**
+   * Sets the ReadOnly flag in the attributes of the 'prototype' property
+   * of functions created from this FunctionTemplate to true.
+   */
+  void ReadOnlyPrototype();
+
+  /**
+   * Removes the prototype property from functions created from this
+   * FunctionTemplate.
+   */
+  void RemovePrototype();
+
+  /**
+   * Returns true if the given object is an instance of this function
+   * template.
+   */
+  bool HasInstance(Local<Value> object);
+
+ private:
+  FunctionTemplate();
+  friend class Context;
+  friend class ObjectTemplate;
+};
+
+/**
+ * Configuration flags for v8::NamedPropertyHandlerConfiguration or
+ * v8::IndexedPropertyHandlerConfiguration.
+ */
+enum class PropertyHandlerFlags {
+  /**
+   * None.
+   */
+  kNone = 0,
+
+  /**
+   * See ALL_CAN_READ above.
+   */
+  kAllCanRead = 1,
+
+  /** Will not call into interceptor for properties on the receiver or prototype
+   * chain, i.e., only call into interceptor for properties that do not exist.
+   * Currently only valid for named interceptors.
+   */
+  kNonMasking = 1 << 1,
+
+  /**
+   * Will not call into interceptor for symbol lookup.  Only meaningful for
+   * named interceptors.
+   */
+  kOnlyInterceptStrings = 1 << 2,
+};
+
+struct NamedPropertyHandlerConfiguration {
+  NamedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      GenericNamedPropertyGetterCallback getter = 0,
+      GenericNamedPropertySetterCallback setter = 0,
+      GenericNamedPropertyQueryCallback query = 0,
+      GenericNamedPropertyDeleterCallback deleter = 0,
+      GenericNamedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  NamedPropertyHandlerConfiguration(
+      GenericNamedPropertyGetterCallback getter,
+      GenericNamedPropertySetterCallback setter,
+      GenericNamedPropertyDescriptorCallback descriptor,
+      GenericNamedPropertyDeleterCallback deleter,
+      GenericNamedPropertyEnumeratorCallback enumerator,
+      GenericNamedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  GenericNamedPropertyGetterCallback getter;
+  GenericNamedPropertySetterCallback setter;
+  GenericNamedPropertyQueryCallback query;
+  GenericNamedPropertyDeleterCallback deleter;
+  GenericNamedPropertyEnumeratorCallback enumerator;
+  GenericNamedPropertyDefinerCallback definer;
+  GenericNamedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+struct IndexedPropertyHandlerConfiguration {
+  IndexedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      IndexedPropertyGetterCallback getter = 0,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyHandlerConfiguration(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter,
+      IndexedPropertyDescriptorCallback descriptor,
+      IndexedPropertyDeleterCallback deleter,
+      IndexedPropertyEnumeratorCallback enumerator,
+      IndexedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyGetterCallback getter;
+  IndexedPropertySetterCallback setter;
+  IndexedPropertyQueryCallback query;
+  IndexedPropertyDeleterCallback deleter;
+  IndexedPropertyEnumeratorCallback enumerator;
+  IndexedPropertyDefinerCallback definer;
+  IndexedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+/**
+ * An ObjectTemplate is used to create objects at runtime.
+ *
+ * Properties added to an ObjectTemplate are added to each object
+ * created from the ObjectTemplate.
+ */
+class V8_EXPORT ObjectTemplate : public Template {
+ public:
+  /** Creates an ObjectTemplate. */
+  static Local<ObjectTemplate> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> constructor = Local<FunctionTemplate>());
+  static V8_DEPRECATED("Use isolate version", Local<ObjectTemplate> New());
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<ObjectTemplate> FromSnapshot(Isolate* isolate,
+                                                 size_t index);
+
+  /** Creates a new instance of this template.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Object> NewInstance());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(Local<Context> context);
+
+  /**
+   * Sets an accessor on the object template.
+   *
+   * Whenever the property with the given name is accessed on objects
+   * created from this ObjectTemplate the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetAccessor(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+  void SetAccessor(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string is accessed on objects created
+   * from this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * SetNamedPropertyHandler() is different from SetHandler(), in
+   * that the latter can intercept symbol-named properties as well as
+   * string-named properties when called with a
+   * NamedPropertyHandlerConfiguration. New code should use SetHandler().
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if a property is present,
+   *   and if present, get its attributes.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the named
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetNamedPropertyHandler(NamedPropertyGetterCallback getter,
+                               NamedPropertySetterCallback setter = 0,
+                               NamedPropertyQueryCallback query = 0,
+                               NamedPropertyDeleterCallback deleter = 0,
+                               NamedPropertyEnumeratorCallback enumerator = 0,
+                               Local<Value> data = Local<Value>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string or a symbol is accessed on
+   * objects created from this object template, the provided callback is
+   * invoked instead of accessing the property directly on the JavaScript
+   * object.
+   *
+   * @param configuration The NamedPropertyHandlerConfiguration that defines the
+   * callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const NamedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if an object has a property.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the indexed
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetIndexedPropertyHandler(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>()) {
+    SetHandler(IndexedPropertyHandlerConfiguration(getter, setter, query,
+                                                   deleter, enumerator, data));
+  }
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * @param configuration The IndexedPropertyHandlerConfiguration that defines
+   * the callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const IndexedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets the callback to be used when calling instances created from
+   * this template as a function.  If no callback is set, instances
+   * behave like normal JavaScript objects that cannot be called as a
+   * function.
+   */
+  void SetCallAsFunctionHandler(FunctionCallback callback,
+                                Local<Value> data = Local<Value>());
+
+  /**
+   * Mark object instances of the template as undetectable.
+   *
+   * In many ways, undetectable objects behave as though they are not
+   * there.  They behave like 'undefined' in conditionals and when
+   * printed.  However, properties can be accessed and called as on
+   * normal objects.
+   */
+  void MarkAsUndetectable();
+
+  /**
+   * Sets access check callback on the object template and enables access
+   * checks.
+   *
+   * When accessing properties on instances of this object template,
+   * the access check callback will be called to determine whether or
+   * not to allow cross-context access to the properties.
+   */
+  void SetAccessCheckCallback(AccessCheckCallback callback,
+                              Local<Value> data = Local<Value>());
+
+  /**
+   * Like SetAccessCheckCallback but invokes an interceptor on failed access
+   * checks instead of looking up all-can-read properties. You can only use
+   * either this method or SetAccessCheckCallback, but not both at the same
+   * time.
+   */
+  void SetAccessCheckCallbackAndHandler(
+      AccessCheckCallback callback,
+      const NamedPropertyHandlerConfiguration& named_handler,
+      const IndexedPropertyHandlerConfiguration& indexed_handler,
+      Local<Value> data = Local<Value>());
+
+  /**
+   * Gets the number of internal fields for objects generated from
+   * this template.
+   */
+  int InternalFieldCount();
+
+  /**
+   * Sets the number of internal fields for objects generated from
+   * this template.
+   */
+  void SetInternalFieldCount(int value);
+
+  /**
+   * Returns true if the object will be an immutable prototype exotic object.
+   */
+  bool IsImmutableProto();
+
+  /**
+   * Makes the ObjectTempate for an immutable prototype exotic object, with an
+   * immutable __proto__.
+   */
+  void SetImmutableProto();
+
+ private:
+  ObjectTemplate();
+  static Local<ObjectTemplate> New(internal::Isolate* isolate,
+                                   Local<FunctionTemplate> constructor);
+  friend class FunctionTemplate;
+};
+
+/**
+ * A Signature specifies which receiver is valid for a function.
+ *
+ * A receiver matches a given signature if the receiver (or any of its
+ * hidden prototypes) was created from the signature's FunctionTemplate, or
+ * from a FunctionTemplate that inherits directly or indirectly from the
+ * signature's FunctionTemplate.
+ */
+class V8_EXPORT Signature : public Data {
+ public:
+  static Local<Signature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  Signature();
+};
+
+
+/**
+ * An AccessorSignature specifies which receivers are valid parameters
+ * to an accessor callback.
+ */
+class V8_EXPORT AccessorSignature : public Data {
+ public:
+  static Local<AccessorSignature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  AccessorSignature();
+};
+
+
+// --- Extensions ---
+
+class V8_EXPORT ExternalOneByteStringResourceImpl
+    : public String::ExternalOneByteStringResource {
+ public:
+  ExternalOneByteStringResourceImpl() : data_(0), length_(0) {}
+  ExternalOneByteStringResourceImpl(const char* data, size_t length)
+      : data_(data), length_(length) {}
+  const char* data() const { return data_; }
+  size_t length() const { return length_; }
+
+ private:
+  const char* data_;
+  size_t length_;
+};
+
+/**
+ * Ignore
+ */
+class V8_EXPORT Extension {  // NOLINT
+ public:
+  // Note that the strings passed into this constructor must live as long
+  // as the Extension itself.
+  Extension(const char* name,
+            const char* source = 0,
+            int dep_count = 0,
+            const char** deps = 0,
+            int source_length = -1);
+  virtual ~Extension() { }
+  virtual Local<FunctionTemplate> GetNativeFunctionTemplate(
+      Isolate* isolate, Local<String> name) {
+    return Local<FunctionTemplate>();
+  }
+
+  const char* name() const { return name_; }
+  size_t source_length() const { return source_length_; }
+  const String::ExternalOneByteStringResource* source() const {
+    return &source_; }
+  int dependency_count() { return dep_count_; }
+  const char** dependencies() { return deps_; }
+  void set_auto_enable(bool value) { auto_enable_ = value; }
+  bool auto_enable() { return auto_enable_; }
+
+  // Disallow copying and assigning.
+  Extension(const Extension&) = delete;
+  void operator=(const Extension&) = delete;
+
+ private:
+  const char* name_;
+  size_t source_length_;  // expected to initialize before source_
+  ExternalOneByteStringResourceImpl source_;
+  int dep_count_;
+  const char** deps_;
+  bool auto_enable_;
+};
+
+
+void V8_EXPORT RegisterExtension(Extension* extension);
+
+
+// --- Statics ---
+
+V8_INLINE Local<Primitive> Undefined(Isolate* isolate);
+V8_INLINE Local<Primitive> Null(Isolate* isolate);
+V8_INLINE Local<Boolean> True(Isolate* isolate);
+V8_INLINE Local<Boolean> False(Isolate* isolate);
+
+/**
+ * A set of constraints that specifies the limits of the runtime's memory use.
+ * You must set the heap size before initializing the VM - the size cannot be
+ * adjusted after the VM is initialized.
+ *
+ * If you are using threads then you should hold the V8::Locker lock while
+ * setting the stack limit and you must set a non-default stack limit separately
+ * for each thread.
+ *
+ * The arguments for set_max_semi_space_size, set_max_old_space_size,
+ * set_max_executable_size, set_code_range_size specify limits in MB.
+ */
+class V8_EXPORT ResourceConstraints {
+ public:
+  ResourceConstraints();
+
+  /**
+   * Configures the constraints with reasonable default values based on the
+   * capabilities of the current device the VM is running on.
+   *
+   * \param physical_memory The total amount of physical memory on the current
+   *   device, in bytes.
+   * \param virtual_memory_limit The amount of virtual memory on the current
+   *   device, in bytes, or zero, if there is no limit.
+   */
+  void ConfigureDefaults(uint64_t physical_memory,
+                         uint64_t virtual_memory_limit);
+
+  int max_semi_space_size() const { return max_semi_space_size_; }
+  void set_max_semi_space_size(int limit_in_mb) {
+    max_semi_space_size_ = limit_in_mb;
+  }
+  int max_old_space_size() const { return max_old_space_size_; }
+  void set_max_old_space_size(int limit_in_mb) {
+    max_old_space_size_ = limit_in_mb;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    int max_executable_size() const) {
+    return max_executable_size_;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    void set_max_executable_size(int limit_in_mb)) {
+    max_executable_size_ = limit_in_mb;
+  }
+  uint32_t* stack_limit() const { return stack_limit_; }
+  // Sets an address beyond which the VM's stack may not grow.
+  void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
+  size_t code_range_size() const { return code_range_size_; }
+  void set_code_range_size(size_t limit_in_mb) {
+    code_range_size_ = limit_in_mb;
+  }
+  size_t max_zone_pool_size() const { return max_zone_pool_size_; }
+  void set_max_zone_pool_size(const size_t bytes) {
+    max_zone_pool_size_ = bytes;
+  }
+
+ private:
+  int max_semi_space_size_;
+  int max_old_space_size_;
+  int max_executable_size_;
+  uint32_t* stack_limit_;
+  size_t code_range_size_;
+  size_t max_zone_pool_size_;
+};
+
+
+// --- Exceptions ---
+
+
+typedef void (*FatalErrorCallback)(const char* location, const char* message);
+
+typedef void (*OOMErrorCallback)(const char* location, bool is_heap_oom);
+
+typedef void (*MessageCallback)(Local<Message> message, Local<Value> data);
+
+// --- Tracing ---
+
+typedef void (*LogEventCallback)(const char* name, int event);
+
+/**
+ * Create new error objects by calling the corresponding error object
+ * constructor with the message.
+ */
+class V8_EXPORT Exception {
+ public:
+  static Local<Value> RangeError(Local<String> message);
+  static Local<Value> ReferenceError(Local<String> message);
+  static Local<Value> SyntaxError(Local<String> message);
+  static Local<Value> TypeError(Local<String> message);
+  static Local<Value> Error(Local<String> message);
+
+  /**
+   * Creates an error message for the given exception.
+   * Will try to reconstruct the original stack trace from the exception value,
+   * or capture the current stack trace if not available.
+   */
+  static Local<Message> CreateMessage(Isolate* isolate, Local<Value> exception);
+  V8_DEPRECATED("Use version with an Isolate*",
+                static Local<Message> CreateMessage(Local<Value> exception));
+
+  /**
+   * Returns the original stack trace that was captured at the creation time
+   * of a given exception, or an empty handle if not available.
+   */
+  static Local<StackTrace> GetStackTrace(Local<Value> exception);
+};
+
+
+// --- Counters Callbacks ---
+
+typedef int* (*CounterLookupCallback)(const char* name);
+
+typedef void* (*CreateHistogramCallback)(const char* name,
+                                         int min,
+                                         int max,
+                                         size_t buckets);
+
+typedef void (*AddHistogramSampleCallback)(void* histogram, int sample);
+
+// --- Memory Allocation Callback ---
+enum ObjectSpace {
+  kObjectSpaceNewSpace = 1 << 0,
+  kObjectSpaceOldSpace = 1 << 1,
+  kObjectSpaceCodeSpace = 1 << 2,
+  kObjectSpaceMapSpace = 1 << 3,
+  kObjectSpaceLoSpace = 1 << 4,
+  kObjectSpaceAll = kObjectSpaceNewSpace | kObjectSpaceOldSpace |
+                    kObjectSpaceCodeSpace | kObjectSpaceMapSpace |
+                    kObjectSpaceLoSpace
+};
+
+  enum AllocationAction {
+    kAllocationActionAllocate = 1 << 0,
+    kAllocationActionFree = 1 << 1,
+    kAllocationActionAll = kAllocationActionAllocate | kAllocationActionFree
+  };
+
+// --- Enter/Leave Script Callback ---
+typedef void (*BeforeCallEnteredCallback)(Isolate*);
+typedef void (*CallCompletedCallback)(Isolate*);
+typedef void (*DeprecatedCallCompletedCallback)();
+
+/**
+ * HostImportDynamicallyCallback is called when we require the
+ * embedder to load a module. This is used as part of the dynamic
+ * import syntax. The behavior of this callback is not specified in
+ * EcmaScript.
+ *
+ * The referrer is the name of the file which calls the dynamic
+ * import. The referrer can be used to resolve the module location.
+ *
+ * The specifier is the name of the module that should be imported.
+ *
+ * The DynamicImportResult object is used to signal success or failure
+ * by calling it's respective methods.
+ *
+ */
+typedef void (*HostImportModuleDynamicallyCallback)(
+    Isolate* isolate, Local<String> referrer, Local<String> specifier,
+    Local<DynamicImportResult> result);
+
+/**
+ * PromiseHook with type kInit is called when a new promise is
+ * created. When a new promise is created as part of the chain in the
+ * case of Promise.then or in the intermediate promises created by
+ * Promise.{race, all}/AsyncFunctionAwait, we pass the parent promise
+ * otherwise we pass undefined.
+ *
+ * PromiseHook with type kResolve is called at the beginning of
+ * resolve or reject function defined by CreateResolvingFunctions.
+ *
+ * PromiseHook with type kBefore is called at the beginning of the
+ * PromiseReactionJob.
+ *
+ * PromiseHook with type kAfter is called right at the end of the
+ * PromiseReactionJob.
+ */
+enum class PromiseHookType { kInit, kResolve, kBefore, kAfter };
+
+typedef void (*PromiseHook)(PromiseHookType type, Local<Promise> promise,
+                            Local<Value> parent);
+
+// --- Promise Reject Callback ---
+enum PromiseRejectEvent {
+  kPromiseRejectWithNoHandler = 0,
+  kPromiseHandlerAddedAfterReject = 1
+};
+
+class PromiseRejectMessage {
+ public:
+  PromiseRejectMessage(Local<Promise> promise, PromiseRejectEvent event,
+                       Local<Value> value, Local<StackTrace> stack_trace)
+      : promise_(promise),
+        event_(event),
+        value_(value),
+        stack_trace_(stack_trace) {}
+
+  V8_INLINE Local<Promise> GetPromise() const { return promise_; }
+  V8_INLINE PromiseRejectEvent GetEvent() const { return event_; }
+  V8_INLINE Local<Value> GetValue() const { return value_; }
+
+  V8_DEPRECATED("Use v8::Exception::CreateMessage(GetValue())->GetStackTrace()",
+                V8_INLINE Local<StackTrace> GetStackTrace() const) {
+    return stack_trace_;
+  }
+
+ private:
+  Local<Promise> promise_;
+  PromiseRejectEvent event_;
+  Local<Value> value_;
+  Local<StackTrace> stack_trace_;
+};
+
+typedef void (*PromiseRejectCallback)(PromiseRejectMessage message);
+
+// --- Microtasks Callbacks ---
+typedef void (*MicrotasksCompletedCallback)(Isolate*);
+typedef void (*MicrotaskCallback)(void* data);
+
+
+/**
+ * Policy for running microtasks:
+ *   - explicit: microtasks are invoked with Isolate::RunMicrotasks() method;
+ *   - scoped: microtasks invocation is controlled by MicrotasksScope objects;
+ *   - auto: microtasks are invoked when the script call depth decrements
+ *           to zero.
+ */
+enum class MicrotasksPolicy { kExplicit, kScoped, kAuto };
+
+
+/**
+ * This scope is used to control microtasks when kScopeMicrotasksInvocation
+ * is used on Isolate. In this mode every non-primitive call to V8 should be
+ * done inside some MicrotasksScope.
+ * Microtasks are executed when topmost MicrotasksScope marked as kRunMicrotasks
+ * exits.
+ * kDoNotRunMicrotasks should be used to annotate calls not intended to trigger
+ * microtasks.
+ */
+class V8_EXPORT MicrotasksScope {
+ public:
+  enum Type { kRunMicrotasks, kDoNotRunMicrotasks };
+
+  MicrotasksScope(Isolate* isolate, Type type);
+  ~MicrotasksScope();
+
+  /**
+   * Runs microtasks if no kRunMicrotasks scope is currently active.
+   */
+  static void PerformCheckpoint(Isolate* isolate);
+
+  /**
+   * Returns current depth of nested kRunMicrotasks scopes.
+   */
+  static int GetCurrentDepth(Isolate* isolate);
+
+  /**
+   * Returns true while microtasks are being executed.
+   */
+  static bool IsRunningMicrotasks(Isolate* isolate);
+
+  // Prevent copying.
+  MicrotasksScope(const MicrotasksScope&) = delete;
+  MicrotasksScope& operator=(const MicrotasksScope&) = delete;
+
+ private:
+  internal::Isolate* const isolate_;
+  bool run_;
+};
+
+
+// --- Failed Access Check Callback ---
+typedef void (*FailedAccessCheckCallback)(Local<Object> target,
+                                          AccessType type,
+                                          Local<Value> data);
+
+// --- AllowCodeGenerationFromStrings callbacks ---
+
+/**
+ * Callback to check if code generation from strings is allowed. See
+ * Context::AllowCodeGenerationFromStrings.
+ */
+typedef bool (*AllowCodeGenerationFromStringsCallback)(Local<Context> context);
+
+// --- WASM compilation callbacks ---
+typedef bool (*ExtensionCallback)(const FunctionCallbackInfo<Value>&);
+
+// --- Garbage Collection Callbacks ---
+
+/**
+ * Applications can register callback functions which will be called before and
+ * after certain garbage collection operations.  Allocations are not allowed in
+ * the callback functions, you therefore cannot manipulate objects (set or
+ * delete properties for example) since it is possible such operations will
+ * result in the allocation of objects.
+ */
+enum GCType {
+  kGCTypeScavenge = 1 << 0,
+  kGCTypeMarkSweepCompact = 1 << 1,
+  kGCTypeIncrementalMarking = 1 << 2,
+  kGCTypeProcessWeakCallbacks = 1 << 3,
+  kGCTypeAll = kGCTypeScavenge | kGCTypeMarkSweepCompact |
+               kGCTypeIncrementalMarking | kGCTypeProcessWeakCallbacks
+};
+
+/**
+ * GCCallbackFlags is used to notify additional information about the GC
+ * callback.
+ *   - kGCCallbackFlagConstructRetainedObjectInfos: The GC callback is for
+ *     constructing retained object infos.
+ *   - kGCCallbackFlagForced: The GC callback is for a forced GC for testing.
+ *   - kGCCallbackFlagSynchronousPhantomCallbackProcessing: The GC callback
+ *     is called synchronously without getting posted to an idle task.
+ *   - kGCCallbackFlagCollectAllAvailableGarbage: The GC callback is called
+ *     in a phase where V8 is trying to collect all available garbage
+ *     (e.g., handling a low memory notification).
+ *   - kGCCallbackScheduleIdleGarbageCollection: The GC callback is called to
+ *     trigger an idle garbage collection.
+ */
+enum GCCallbackFlags {
+  kNoGCCallbackFlags = 0,
+  kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1,
+  kGCCallbackFlagForced = 1 << 2,
+  kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3,
+  kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4,
+  kGCCallbackFlagCollectAllExternalMemory = 1 << 5,
+  kGCCallbackScheduleIdleGarbageCollection = 1 << 6,
+};
+
+typedef void (*GCCallback)(GCType type, GCCallbackFlags flags);
+
+typedef void (*InterruptCallback)(Isolate* isolate, void* data);
+
+
+/**
+ * Collection of V8 heap information.
+ *
+ * Instances of this class can be passed to v8::V8::HeapStatistics to
+ * get heap statistics from V8.
+ */
+class V8_EXPORT HeapStatistics {
+ public:
+  HeapStatistics();
+  size_t total_heap_size() { return total_heap_size_; }
+  size_t total_heap_size_executable() { return total_heap_size_executable_; }
+  size_t total_physical_size() { return total_physical_size_; }
+  size_t total_available_size() { return total_available_size_; }
+  size_t used_heap_size() { return used_heap_size_; }
+  size_t heap_size_limit() { return heap_size_limit_; }
+  size_t malloced_memory() { return malloced_memory_; }
+  size_t peak_malloced_memory() { return peak_malloced_memory_; }
+
+  /**
+   * Returns a 0/1 boolean, which signifies whether the V8 overwrite heap
+   * garbage with a bit pattern.
+   */
+  size_t does_zap_garbage() { return does_zap_garbage_; }
+
+ private:
+  size_t total_heap_size_;
+  size_t total_heap_size_executable_;
+  size_t total_physical_size_;
+  size_t total_available_size_;
+  size_t used_heap_size_;
+  size_t heap_size_limit_;
+  size_t malloced_memory_;
+  size_t peak_malloced_memory_;
+  bool does_zap_garbage_;
+
+  friend class V8;
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapSpaceStatistics {
+ public:
+  HeapSpaceStatistics();
+  const char* space_name() { return space_name_; }
+  size_t space_size() { return space_size_; }
+  size_t space_used_size() { return space_used_size_; }
+  size_t space_available_size() { return space_available_size_; }
+  size_t physical_space_size() { return physical_space_size_; }
+
+ private:
+  const char* space_name_;
+  size_t space_size_;
+  size_t space_used_size_;
+  size_t space_available_size_;
+  size_t physical_space_size_;
+
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapObjectStatistics {
+ public:
+  HeapObjectStatistics();
+  const char* object_type() { return object_type_; }
+  const char* object_sub_type() { return object_sub_type_; }
+  size_t object_count() { return object_count_; }
+  size_t object_size() { return object_size_; }
+
+ private:
+  const char* object_type_;
+  const char* object_sub_type_;
+  size_t object_count_;
+  size_t object_size_;
+
+  friend class Isolate;
+};
+
+class V8_EXPORT HeapCodeStatistics {
+ public:
+  HeapCodeStatistics();
+  size_t code_and_metadata_size() { return code_and_metadata_size_; }
+  size_t bytecode_and_metadata_size() { return bytecode_and_metadata_size_; }
+
+ private:
+  size_t code_and_metadata_size_;
+  size_t bytecode_and_metadata_size_;
+
+  friend class Isolate;
+};
+
+class RetainedObjectInfo;
+
+
+/**
+ * FunctionEntryHook is the type of the profile entry hook called at entry to
+ * any generated function when function-level profiling is enabled.
+ *
+ * \param function the address of the function that's being entered.
+ * \param return_addr_location points to a location on stack where the machine
+ *    return address resides. This can be used to identify the caller of
+ *    \p function, and/or modified to divert execution when \p function exits.
+ *
+ * \note the entry hook must not cause garbage collection.
+ */
+typedef void (*FunctionEntryHook)(uintptr_t function,
+                                  uintptr_t return_addr_location);
+
+/**
+ * A JIT code event is issued each time code is added, moved or removed.
+ *
+ * \note removal events are not currently issued.
+ */
+struct JitCodeEvent {
+  enum EventType {
+    CODE_ADDED,
+    CODE_MOVED,
+    CODE_REMOVED,
+    CODE_ADD_LINE_POS_INFO,
+    CODE_START_LINE_INFO_RECORDING,
+    CODE_END_LINE_INFO_RECORDING
+  };
+  // Definition of the code position type. The "POSITION" type means the place
+  // in the source code which are of interest when making stack traces to
+  // pin-point the source location of a stack frame as close as possible.
+  // The "STATEMENT_POSITION" means the place at the beginning of each
+  // statement, and is used to indicate possible break locations.
+  enum PositionType { POSITION, STATEMENT_POSITION };
+
+  // Type of event.
+  EventType type;
+  // Start of the instructions.
+  void* code_start;
+  // Size of the instructions.
+  size_t code_len;
+  // Script info for CODE_ADDED event.
+  Local<UnboundScript> script;
+  // User-defined data for *_LINE_INFO_* event. It's used to hold the source
+  // code line information which is returned from the
+  // CODE_START_LINE_INFO_RECORDING event. And it's passed to subsequent
+  // CODE_ADD_LINE_POS_INFO and CODE_END_LINE_INFO_RECORDING events.
+  void* user_data;
+
+  struct name_t {
+    // Name of the object associated with the code, note that the string is not
+    // zero-terminated.
+    const char* str;
+    // Number of chars in str.
+    size_t len;
+  };
+
+  struct line_info_t {
+    // PC offset
+    size_t offset;
+    // Code postion
+    size_t pos;
+    // The position type.
+    PositionType position_type;
+  };
+
+  union {
+    // Only valid for CODE_ADDED.
+    struct name_t name;
+
+    // Only valid for CODE_ADD_LINE_POS_INFO
+    struct line_info_t line_info;
+
+    // New location of instructions. Only valid for CODE_MOVED.
+    void* new_code_start;
+  };
+};
+
+/**
+ * Option flags passed to the SetRAILMode function.
+ * See documentation https://developers.google.com/web/tools/chrome-devtools/
+ * profile/evaluate-performance/rail
+ */
+enum RAILMode {
+  // Response performance mode: In this mode very low virtual machine latency
+  // is provided. V8 will try to avoid JavaScript execution interruptions.
+  // Throughput may be throttled.
+  PERFORMANCE_RESPONSE,
+  // Animation performance mode: In this mode low virtual machine latency is
+  // provided. V8 will try to avoid as many JavaScript execution interruptions
+  // as possible. Throughput may be throttled. This is the default mode.
+  PERFORMANCE_ANIMATION,
+  // Idle performance mode: The embedder is idle. V8 can complete deferred work
+  // in this mode.
+  PERFORMANCE_IDLE,
+  // Load performance mode: In this mode high throughput is provided. V8 may
+  // turn off latency optimizations.
+  PERFORMANCE_LOAD
+};
+
+/**
+ * Option flags passed to the SetJitCodeEventHandler function.
+ */
+enum JitCodeEventOptions {
+  kJitCodeEventDefault = 0,
+  // Generate callbacks for already existent code.
+  kJitCodeEventEnumExisting = 1
+};
+
+
+/**
+ * Callback function passed to SetJitCodeEventHandler.
+ *
+ * \param event code add, move or removal event.
+ */
+typedef void (*JitCodeEventHandler)(const JitCodeEvent* event);
+
+
+/**
+ * Interface for iterating through all external resources in the heap.
+ */
+class V8_EXPORT ExternalResourceVisitor {  // NOLINT
+ public:
+  virtual ~ExternalResourceVisitor() {}
+  virtual void VisitExternalString(Local<String> string) {}
+};
+
+
+/**
+ * Interface for iterating through all the persistent handles in the heap.
+ */
+class V8_EXPORT PersistentHandleVisitor {  // NOLINT
+ public:
+  virtual ~PersistentHandleVisitor() {}
+  virtual void VisitPersistentHandle(Persistent<Value>* value,
+                                     uint16_t class_id) {}
+};
+
+/**
+ * Memory pressure level for the MemoryPressureNotification.
+ * kNone hints V8 that there is no memory pressure.
+ * kModerate hints V8 to speed up incremental garbage collection at the cost of
+ * of higher latency due to garbage collection pauses.
+ * kCritical hints V8 to free memory as soon as possible. Garbage collection
+ * pauses at this level will be large.
+ */
+enum class MemoryPressureLevel { kNone, kModerate, kCritical };
+
+/**
+ * Interface for tracing through the embedder heap. During a v8 garbage
+ * collection, v8 collects hidden fields of all potential wrappers, and at the
+ * end of its marking phase iterates the collection and asks the embedder to
+ * trace through its heap and use reporter to report each JavaScript object
+ * reachable from any of the given wrappers.
+ *
+ * Before the first call to the TraceWrappersFrom function TracePrologue will be
+ * called. When the garbage collection cycle is finished, TraceEpilogue will be
+ * called.
+ */
+class V8_EXPORT EmbedderHeapTracer {
+ public:
+  enum ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION };
+
+  struct AdvanceTracingActions {
+    explicit AdvanceTracingActions(ForceCompletionAction force_completion_)
+        : force_completion(force_completion_) {}
+
+    ForceCompletionAction force_completion;
+  };
+
+  /**
+   * Called by v8 to register internal fields of found wrappers.
+   *
+   * The embedder is expected to store them somewhere and trace reachable
+   * wrappers from them when called through |AdvanceTracing|.
+   */
+  virtual void RegisterV8References(
+      const std::vector<std::pair<void*, void*> >& embedder_fields) = 0;
+
+  /**
+   * Called at the beginning of a GC cycle.
+   */
+  virtual void TracePrologue() = 0;
+
+  /**
+   * Called to to make a tracing step in the embedder.
+   *
+   * The embedder is expected to trace its heap starting from wrappers reported
+   * by RegisterV8References method, and report back all reachable wrappers.
+   * Furthermore, the embedder is expected to stop tracing by the given
+   * deadline.
+   *
+   * Returns true if there is still work to do.
+   */
+  virtual bool AdvanceTracing(double deadline_in_ms,
+                              AdvanceTracingActions actions) = 0;
+
+  /**
+   * Called at the end of a GC cycle.
+   *
+   * Note that allocation is *not* allowed within |TraceEpilogue|.
+   */
+  virtual void TraceEpilogue() = 0;
+
+  /**
+   * Called upon entering the final marking pause. No more incremental marking
+   * steps will follow this call.
+   */
+  virtual void EnterFinalPause() = 0;
+
+  /**
+   * Called when tracing is aborted.
+   *
+   * The embedder is expected to throw away all intermediate data and reset to
+   * the initial state.
+   */
+  virtual void AbortTracing() = 0;
+
+  /**
+   * Returns the number of wrappers that are still to be traced by the embedder.
+   */
+  virtual size_t NumberOfWrappersToTrace() { return 0; }
+
+ protected:
+  virtual ~EmbedderHeapTracer() = default;
+};
+
+/**
+ * Callback and supporting data used in SnapshotCreator to implement embedder
+ * logic to serialize internal fields.
+ */
+struct SerializeInternalFieldsCallback {
+  typedef StartupData (*CallbackFunction)(Local<Object> holder, int index,
+                                          void* data);
+  SerializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                  void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  CallbackFunction callback;
+  void* data;
+};
+// Note that these fields are called "internal fields" in the API and called
+// "embedder fields" within V8.
+typedef SerializeInternalFieldsCallback SerializeEmbedderFieldsCallback;
+
+/**
+ * Callback and supporting data used to implement embedder logic to deserialize
+ * internal fields.
+ */
+struct DeserializeInternalFieldsCallback {
+  typedef void (*CallbackFunction)(Local<Object> holder, int index,
+                                   StartupData payload, void* data);
+  DeserializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                    void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  void (*callback)(Local<Object> holder, int index, StartupData payload,
+                   void* data);
+  void* data;
+};
+typedef DeserializeInternalFieldsCallback DeserializeEmbedderFieldsCallback;
+
+/**
+ * Isolate represents an isolated instance of the V8 engine.  V8 isolates have
+ * completely separate states.  Objects from one isolate must not be used in
+ * other isolates.  The embedder can create multiple isolates and use them in
+ * parallel in multiple threads.  An isolate can be entered by at most one
+ * thread at any given time.  The Locker/Unlocker API must be used to
+ * synchronize.
+ */
+class V8_EXPORT Isolate {
+ public:
+  /**
+   * Initial configuration parameters for a new Isolate.
+   */
+  struct CreateParams {
+    CreateParams()
+        : entry_hook(nullptr),
+          code_event_handler(nullptr),
+          snapshot_blob(nullptr),
+          counter_lookup_callback(nullptr),
+          create_histogram_callback(nullptr),
+          add_histogram_sample_callback(nullptr),
+          array_buffer_allocator(nullptr),
+          external_references(nullptr),
+          allow_atomics_wait(true),
+          host_import_module_dynamically_callback_(nullptr) {}
+
+    /**
+     * The optional entry_hook allows the host application to provide the
+     * address of a function that's invoked on entry to every V8-generated
+     * function.  Note that entry_hook is invoked at the very start of each
+     * generated function.
+     * An entry_hook can only be provided in no-snapshot builds; in snapshot
+     * builds it must be nullptr.
+     */
+    FunctionEntryHook entry_hook;
+
+    /**
+     * Allows the host application to provide the address of a function that is
+     * notified each time code is added, moved or removed.
+     */
+    JitCodeEventHandler code_event_handler;
+
+    /**
+     * ResourceConstraints to use for the new Isolate.
+     */
+    ResourceConstraints constraints;
+
+    /**
+     * Explicitly specify a startup snapshot blob. The embedder owns the blob.
+     */
+    StartupData* snapshot_blob;
+
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * statistics counters.
+     */
+    CounterLookupCallback counter_lookup_callback;
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * histograms. The CreateHistogram function returns a
+     * histogram which will later be passed to the AddHistogramSample
+     * function.
+     */
+    CreateHistogramCallback create_histogram_callback;
+    AddHistogramSampleCallback add_histogram_sample_callback;
+
+    /**
+     * The ArrayBuffer::Allocator to use for allocating and freeing the backing
+     * store of ArrayBuffers.
+     */
+    ArrayBuffer::Allocator* array_buffer_allocator;
+
+    /**
+     * Specifies an optional nullptr-terminated array of raw addresses in the
+     * embedder that V8 can match against during serialization and use for
+     * deserialization. This array and its content must stay valid for the
+     * entire lifetime of the isolate.
+     */
+    intptr_t* external_references;
+
+    /**
+     * Whether calling Atomics.wait (a function that may block) is allowed in
+     * this isolate. This can also be configured via SetAllowAtomicsWait.
+     */
+    bool allow_atomics_wait;
+
+    /**
+     * This is an unfinished experimental feature, and is only exposed
+     * here for internal testing purposes. DO NOT USE.
+     *
+     * This specifies the callback called by the upcoming dynamic
+     * import() language feature to load modules.
+     */
+    HostImportModuleDynamicallyCallback
+        host_import_module_dynamically_callback_;
+  };
+
+
+  /**
+   * Stack-allocated class which sets the isolate for all operations
+   * executed within a local scope.
+   */
+  class V8_EXPORT Scope {
+   public:
+    explicit Scope(Isolate* isolate) : isolate_(isolate) {
+      isolate->Enter();
+    }
+
+    ~Scope() { isolate_->Exit(); }
+
+    // Prevent copying of Scope objects.
+    Scope(const Scope&) = delete;
+    Scope& operator=(const Scope&) = delete;
+
+   private:
+    Isolate* const isolate_;
+  };
+
+
+  /**
+   * Assert that no Javascript code is invoked.
+   */
+  class V8_EXPORT DisallowJavascriptExecutionScope {
+   public:
+    enum OnFailure { CRASH_ON_FAILURE, THROW_ON_FAILURE };
+
+    DisallowJavascriptExecutionScope(Isolate* isolate, OnFailure on_failure);
+    ~DisallowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    DisallowJavascriptExecutionScope(const DisallowJavascriptExecutionScope&) =
+        delete;
+    DisallowJavascriptExecutionScope& operator=(
+        const DisallowJavascriptExecutionScope&) = delete;
+
+   private:
+    bool on_failure_;
+    void* internal_;
+  };
+
+
+  /**
+   * Introduce exception to DisallowJavascriptExecutionScope.
+   */
+  class V8_EXPORT AllowJavascriptExecutionScope {
+   public:
+    explicit AllowJavascriptExecutionScope(Isolate* isolate);
+    ~AllowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    AllowJavascriptExecutionScope(const AllowJavascriptExecutionScope&) =
+        delete;
+    AllowJavascriptExecutionScope& operator=(
+        const AllowJavascriptExecutionScope&) = delete;
+
+   private:
+    void* internal_throws_;
+    void* internal_assert_;
+  };
+
+  /**
+   * Do not run microtasks while this scope is active, even if microtasks are
+   * automatically executed otherwise.
+   */
+  class V8_EXPORT SuppressMicrotaskExecutionScope {
+   public:
+    explicit SuppressMicrotaskExecutionScope(Isolate* isolate);
+    ~SuppressMicrotaskExecutionScope();
+
+    // Prevent copying of Scope objects.
+    SuppressMicrotaskExecutionScope(const SuppressMicrotaskExecutionScope&) =
+        delete;
+    SuppressMicrotaskExecutionScope& operator=(
+        const SuppressMicrotaskExecutionScope&) = delete;
+
+   private:
+    internal::Isolate* const isolate_;
+  };
+
+  /**
+   * Types of garbage collections that can be requested via
+   * RequestGarbageCollectionForTesting.
+   */
+  enum GarbageCollectionType {
+    kFullGarbageCollection,
+    kMinorGarbageCollection
+  };
+
+  /**
+   * Features reported via the SetUseCounterCallback callback. Do not change
+   * assigned numbers of existing items; add new features to the end of this
+   * list.
+   */
+  enum UseCounterFeature {
+    kUseAsm = 0,
+    kBreakIterator = 1,
+    kLegacyConst = 2,
+    kMarkDequeOverflow = 3,
+    kStoreBufferOverflow = 4,
+    kSlotsBufferOverflow = 5,
+    kObjectObserve = 6,
+    kForcedGC = 7,
+    kSloppyMode = 8,
+    kStrictMode = 9,
+    kStrongMode = 10,
+    kRegExpPrototypeStickyGetter = 11,
+    kRegExpPrototypeToString = 12,
+    kRegExpPrototypeUnicodeGetter = 13,
+    kIntlV8Parse = 14,
+    kIntlPattern = 15,
+    kIntlResolved = 16,
+    kPromiseChain = 17,
+    kPromiseAccept = 18,
+    kPromiseDefer = 19,
+    kHtmlCommentInExternalScript = 20,
+    kHtmlComment = 21,
+    kSloppyModeBlockScopedFunctionRedefinition = 22,
+    kForInInitializer = 23,
+    kArrayProtectorDirtied = 24,
+    kArraySpeciesModified = 25,
+    kArrayPrototypeConstructorModified = 26,
+    kArrayInstanceProtoModified = 27,
+    kArrayInstanceConstructorModified = 28,
+    kLegacyFunctionDeclaration = 29,
+    kRegExpPrototypeSourceGetter = 30,
+    kRegExpPrototypeOldFlagGetter = 31,
+    kDecimalWithLeadingZeroInStrictMode = 32,
+    kLegacyDateParser = 33,
+    kDefineGetterOrSetterWouldThrow = 34,
+    kFunctionConstructorReturnedUndefined = 35,
+    kAssigmentExpressionLHSIsCallInSloppy = 36,
+    kAssigmentExpressionLHSIsCallInStrict = 37,
+    kPromiseConstructorReturnedUndefined = 38,
+
+    // If you add new values here, you'll also need to update Chromium's:
+    // UseCounter.h, V8PerIsolateData.cpp, histograms.xml
+    kUseCounterFeatureCount  // This enum value must be last.
+  };
+
+  enum MessageErrorLevel {
+    kMessageLog = (1 << 0),
+    kMessageDebug = (1 << 1),
+    kMessageInfo = (1 << 2),
+    kMessageError = (1 << 3),
+    kMessageWarning = (1 << 4),
+    kMessageAll = kMessageLog | kMessageDebug | kMessageInfo | kMessageError |
+                  kMessageWarning,
+  };
+
+  typedef void (*UseCounterCallback)(Isolate* isolate,
+                                     UseCounterFeature feature);
+
+
+  /**
+   * Creates a new isolate.  Does not change the currently entered
+   * isolate.
+   *
+   * When an isolate is no longer used its resources should be freed
+   * by calling Dispose().  Using the delete operator is not allowed.
+   *
+   * V8::Initialize() must have run prior to this.
+   */
+  static Isolate* New(const CreateParams& params);
+
+  /**
+   * Returns the entered isolate for the current thread or NULL in
+   * case there is no current isolate.
+   *
+   * This method must not be invoked before V8::Initialize() was invoked.
+   */
+  static Isolate* GetCurrent();
+
+  /**
+   * Custom callback used by embedders to help V8 determine if it should abort
+   * when it throws and no internal handler is predicted to catch the
+   * exception. If --abort-on-uncaught-exception is used on the command line,
+   * then V8 will abort if either:
+   * - no custom callback is set.
+   * - the custom callback set returns true.
+   * Otherwise, the custom callback will not be called and V8 will not abort.
+   */
+  typedef bool (*AbortOnUncaughtExceptionCallback)(Isolate*);
+  void SetAbortOnUncaughtExceptionCallback(
+      AbortOnUncaughtExceptionCallback callback);
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to guide heuristics.
+   * It is allowed to call this function from another thread while
+   * the isolate is executing long running JavaScript code.
+   */
+  void MemoryPressureNotification(MemoryPressureLevel level);
+
+  /**
+   * Methods below this point require holding a lock (using Locker) in
+   * a multi-threaded environment.
+   */
+
+  /**
+   * Sets this isolate as the entered one for the current thread.
+   * Saves the previously entered one (if any), so that it can be
+   * restored when exiting.  Re-entering an isolate is allowed.
+   */
+  void Enter();
+
+  /**
+   * Exits this isolate by restoring the previously entered one in the
+   * current thread.  The isolate may still stay the same, if it was
+   * entered more than once.
+   *
+   * Requires: this == Isolate::GetCurrent().
+   */
+  void Exit();
+
+  /**
+   * Disposes the isolate.  The isolate must not be entered by any
+   * thread to be disposable.
+   */
+  void Dispose();
+
+  /**
+   * Dumps activated low-level V8 internal stats. This can be used instead
+   * of performing a full isolate disposal.
+   */
+  void DumpAndResetStats();
+
+  /**
+   * Discards all V8 thread-specific data for the Isolate. Should be used
+   * if a thread is terminating and it has used an Isolate that will outlive
+   * the thread -- all thread-specific data for an Isolate is discarded when
+   * an Isolate is disposed so this call is pointless if an Isolate is about
+   * to be Disposed.
+   */
+  void DiscardThreadSpecificMetadata();
+
+  /**
+   * Associate embedder-specific data with the isolate. |slot| has to be
+   * between 0 and GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE void SetData(uint32_t slot, void* data);
+
+  /**
+   * Retrieve embedder-specific data from the isolate.
+   * Returns NULL if SetData has never been called for the given |slot|.
+   */
+  V8_INLINE void* GetData(uint32_t slot);
+
+  /**
+   * Returns the maximum number of available embedder data slots. Valid slots
+   * are in the range of 0 - GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE static uint32_t GetNumberOfDataSlots();
+
+  /**
+   * Get statistics about the heap memory usage.
+   */
+  void GetHeapStatistics(HeapStatistics* heap_statistics);
+
+  /**
+   * Returns the number of spaces in the heap.
+   */
+  size_t NumberOfHeapSpaces();
+
+  /**
+   * Get the memory usage of a space in the heap.
+   *
+   * \param space_statistics The HeapSpaceStatistics object to fill in
+   *   statistics.
+   * \param index The index of the space to get statistics from, which ranges
+   *   from 0 to NumberOfHeapSpaces() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapSpaceStatistics(HeapSpaceStatistics* space_statistics,
+                              size_t index);
+
+  /**
+   * Returns the number of types of objects tracked in the heap at GC.
+   */
+  size_t NumberOfTrackedHeapObjectTypes();
+
+  /**
+   * Get statistics about objects in the heap.
+   *
+   * \param object_statistics The HeapObjectStatistics object to fill in
+   *   statistics of objects of given type, which were live in the previous GC.
+   * \param type_index The index of the type of object to fill details about,
+   *   which ranges from 0 to NumberOfTrackedHeapObjectTypes() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapObjectStatisticsAtLastGC(HeapObjectStatistics* object_statistics,
+                                       size_t type_index);
+
+  /**
+   * Get statistics about code and its metadata in the heap.
+   *
+   * \param object_statistics The HeapCodeStatistics object to fill in
+   *   statistics of code, bytecode and their metadata.
+   * \returns true on success.
+   */
+  bool GetHeapCodeAndMetadataStatistics(HeapCodeStatistics* object_statistics);
+
+  /**
+   * Get a call stack sample from the isolate.
+   * \param state Execution state.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \note GetStackSample should only be called when the JS thread is paused or
+   *       interrupted. Otherwise the behavior is undefined.
+   */
+  void GetStackSample(const RegisterState& state, void** frames,
+                      size_t frames_limit, SampleInfo* sample_info);
+
+  /**
+   * Adjusts the amount of registered external memory. Used to give V8 an
+   * indication of the amount of externally allocated memory that is kept alive
+   * by JavaScript objects. V8 uses this to decide when to perform global
+   * garbage collections. Registering externally allocated memory will trigger
+   * global garbage collections more often than it would otherwise in an attempt
+   * to garbage collect the JavaScript objects that keep the externally
+   * allocated memory alive.
+   *
+   * \param change_in_bytes the change in externally allocated memory that is
+   *   kept alive by JavaScript objects.
+   * \returns the adjusted value.
+   */
+  V8_INLINE int64_t
+      AdjustAmountOfExternalAllocatedMemory(int64_t change_in_bytes);
+
+  /**
+   * Returns the number of phantom handles without callbacks that were reset
+   * by the garbage collector since the last call to this function.
+   */
+  size_t NumberOfPhantomHandleResetsSinceLastCall();
+
+  /**
+   * Returns heap profiler for this isolate. Will return NULL until the isolate
+   * is initialized.
+   */
+  HeapProfiler* GetHeapProfiler();
+
+  /**
+   * Returns CPU profiler for this isolate. Will return NULL unless the isolate
+   * is initialized. It is the embedder's responsibility to stop all CPU
+   * profiling activities if it has started any.
+   */
+  V8_DEPRECATE_SOON("CpuProfiler should be created with CpuProfiler::New call.",
+                    CpuProfiler* GetCpuProfiler());
+
+  /** Returns true if this isolate has a current context. */
+  bool InContext();
+
+  /**
+   * Returns the context of the currently running JavaScript, or the context
+   * on the top of the stack if no JavaScript is running.
+   */
+  Local<Context> GetCurrentContext();
+
+  /**
+   * Returns the context of the calling JavaScript code.  That is the
+   * context of the top-most JavaScript frame.  If there are no
+   * JavaScript frames an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON(
+      "Calling context concept is not compatible with tail calls, and will be "
+      "removed.",
+      Local<Context> GetCallingContext());
+
+  /** Returns the last context entered through V8's C++ API. */
+  Local<Context> GetEnteredContext();
+
+  /**
+   * Returns either the last context entered through V8's C++ API, or the
+   * context of the currently running microtask while processing microtasks.
+   * If a context is entered while executing a microtask, that context is
+   * returned.
+   */
+  Local<Context> GetEnteredOrMicrotaskContext();
+
+  /**
+   * Schedules an exception to be thrown when returning to JavaScript.  When an
+   * exception has been scheduled it is illegal to invoke any JavaScript
+   * operation; the caller must return immediately and only after the exception
+   * has been handled does it become legal to invoke JavaScript operations.
+   */
+  Local<Value> ThrowException(Local<Value> exception);
+
+  typedef void (*GCCallback)(Isolate* isolate, GCType type,
+                             GCCallbackFlags flags);
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCPrologueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  void RemoveGCPrologueCallback(GCCallback callback);
+
+  /**
+   * Sets the embedder heap tracer for the isolate.
+   */
+  void SetEmbedderHeapTracer(EmbedderHeapTracer* tracer);
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCEpilogueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  void RemoveGCEpilogueCallback(GCCallback callback);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void TerminateExecution();
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   */
+  bool IsExecutionTerminating();
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void CancelTerminateExecution();
+
+  /**
+   * Request V8 to interrupt long running JavaScript code and invoke
+   * the given |callback| passing the given |data| to it. After |callback|
+   * returns control will be returned to the JavaScript code.
+   * There may be a number of interrupt requests in flight.
+   * Can be called from another thread without acquiring a |Locker|.
+   * Registered |callback| must not reenter interrupted Isolate.
+   */
+  void RequestInterrupt(InterruptCallback callback, void* data);
+
+  /**
+   * Request garbage collection in this Isolate. It is only valid to call this
+   * function if --expose_gc was specified.
+   *
+   * This should only be used for testing purposes and not to enforce a garbage
+   * collection schedule. It has strong negative impact on the garbage
+   * collection performance. Use IdleNotificationDeadline() or
+   * LowMemoryNotification() instead to influence the garbage collection
+   * schedule.
+   */
+  void RequestGarbageCollectionForTesting(GarbageCollectionType type);
+
+  /**
+   * Set the callback to invoke for logging event.
+   */
+  void SetEventLogger(LogEventCallback that);
+
+  /**
+   * Adds a callback to notify the host application right before a script
+   * is about to run. If a script re-enters the runtime during executing, the
+   * BeforeCallEnteredCallback is invoked for each re-entrance.
+   * Executing scripts inside the callback will re-trigger the callback.
+   */
+  void AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Removes callback that was installed by AddBeforeCallEnteredCallback.
+   */
+  void RemoveBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Adds a callback to notify the host application when a script finished
+   * running.  If a script re-enters the runtime during executing, the
+   * CallCompletedCallback is only invoked when the outer-most script
+   * execution ends.  Executing scripts inside the callback do not trigger
+   * further callbacks.
+   */
+  void AddCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void AddCallCompletedCallback(DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Removes callback that was installed by AddCallCompletedCallback.
+   */
+  void RemoveCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void RemoveCallCompletedCallback(
+          DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Experimental: Set the PromiseHook callback for various promise
+   * lifecycle events.
+   */
+  void SetPromiseHook(PromiseHook hook);
+
+  /**
+   * Set callback to notify about promise reject with no handler, or
+   * revocation of such a previous notification once the handler is added.
+   */
+  void SetPromiseRejectCallback(PromiseRejectCallback callback);
+
+  /**
+   * Experimental: Runs the Microtask Work Queue until empty
+   * Any exceptions thrown by microtask callbacks are swallowed.
+   */
+  void RunMicrotasks();
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(Local<Function> microtask);
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(MicrotaskCallback microtask, void* data = NULL);
+
+  /**
+   * Experimental: Controls how Microtasks are invoked. See MicrotasksPolicy
+   * for details.
+   */
+  void SetMicrotasksPolicy(MicrotasksPolicy policy);
+  V8_DEPRECATE_SOON("Use SetMicrotasksPolicy",
+                    void SetAutorunMicrotasks(bool autorun));
+
+  /**
+   * Experimental: Returns the policy controlling how Microtasks are invoked.
+   */
+  MicrotasksPolicy GetMicrotasksPolicy() const;
+  V8_DEPRECATE_SOON("Use GetMicrotasksPolicy",
+                    bool WillAutorunMicrotasks() const);
+
+  /**
+   * Experimental: adds a callback to notify the host application after
+   * microtasks were run. The callback is triggered by explicit RunMicrotasks
+   * call or automatic microtasks execution (see SetAutorunMicrotasks).
+   *
+   * Callback will trigger even if microtasks were attempted to run,
+   * but the microtasks queue was empty and no single microtask was actually
+   * executed.
+   *
+   * Executing scriptsinside the callback will not re-trigger microtasks and
+   * the callback.
+   */
+  void AddMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Removes callback that was installed by AddMicrotasksCompletedCallback.
+   */
+  void RemoveMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Sets a callback for counting the number of times a feature of V8 is used.
+   */
+  void SetUseCounterCallback(UseCounterCallback callback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * statistics counters.
+   */
+  void SetCounterFunction(CounterLookupCallback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * histograms. The CreateHistogram function returns a
+   * histogram which will later be passed to the AddHistogramSample
+   * function.
+   */
+  void SetCreateHistogramFunction(CreateHistogramCallback);
+  void SetAddHistogramSampleFunction(AddHistogramSampleCallback);
+
+  /**
+   * Optional notification that the embedder is idle.
+   * V8 uses the notification to perform garbage collection.
+   * This call can be used repeatedly if the embedder remains idle.
+   * Returns true if the embedder should stop calling IdleNotificationDeadline
+   * until real work has been done.  This indicates that V8 has done
+   * as much cleanup as it will be able to do.
+   *
+   * The deadline_in_seconds argument specifies the deadline V8 has to finish
+   * garbage collection work. deadline_in_seconds is compared with
+   * MonotonicallyIncreasingTime() and should be based on the same timebase as
+   * that function. There is no guarantee that the actual work will be done
+   * within the time limit.
+   */
+  bool IdleNotificationDeadline(double deadline_in_seconds);
+
+  V8_DEPRECATED("use IdleNotificationDeadline()",
+                bool IdleNotification(int idle_time_in_ms));
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to attempt to free memory.
+   */
+  void LowMemoryNotification();
+
+  /**
+   * Optional notification that a context has been disposed. V8 uses
+   * these notifications to guide the GC heuristic. Returns the number
+   * of context disposals - including this one - since the last time
+   * V8 had a chance to clean up.
+   *
+   * The optional parameter |dependant_context| specifies whether the disposed
+   * context was depending on state from other contexts or not.
+   */
+  int ContextDisposedNotification(bool dependant_context = true);
+
+  /**
+   * Optional notification that the isolate switched to the foreground.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInForegroundNotification();
+
+  /**
+   * Optional notification that the isolate switched to the background.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInBackgroundNotification();
+
+  /**
+   * Optional notification to tell V8 the current performance requirements
+   * of the embedder based on RAIL.
+   * V8 uses these notifications to guide heuristics.
+   * This is an unfinished experimental feature. Semantics and implementation
+   * may change frequently.
+   */
+  void SetRAILMode(RAILMode rail_mode);
+
+  /**
+   * Optional notification to tell V8 the current isolate is used for debugging
+   * and requires higher heap limit.
+   */
+  void IncreaseHeapLimitForDebugging();
+
+  /**
+   * Restores the original heap limit after IncreaseHeapLimitForDebugging().
+   */
+  void RestoreOriginalHeapLimit();
+
+  /**
+   * Returns true if the heap limit was increased for debugging and the
+   * original heap limit was not restored yet.
+   */
+  bool IsHeapLimitIncreasedForDebugging();
+
+  /**
+   * Allows the host application to provide the address of a function that is
+   * notified each time code is added, moved or removed.
+   *
+   * \param options options for the JIT code event handler.
+   * \param event_handler the JIT code event handler, which will be invoked
+   *     each time code is added, moved or removed.
+   * \note \p event_handler won't get notified of existent code.
+   * \note since code removal notifications are not currently issued, the
+   *     \p event_handler may get notifications of code that overlaps earlier
+   *     code notifications. This happens when code areas are reused, and the
+   *     earlier overlapping code areas should therefore be discarded.
+   * \note the events passed to \p event_handler and the strings they point to
+   *     are not guaranteed to live past each call. The \p event_handler must
+   *     copy strings and other parameters it needs to keep around.
+   * \note the set of events declared in JitCodeEvent::EventType is expected to
+   *     grow over time, and the JitCodeEvent structure is expected to accrue
+   *     new members. The \p event_handler function must ignore event codes
+   *     it does not recognize to maintain future compatibility.
+   * \note Use Isolate::CreateParams to get events for code executed during
+   *     Isolate setup.
+   */
+  void SetJitCodeEventHandler(JitCodeEventOptions options,
+                              JitCodeEventHandler event_handler);
+
+  /**
+   * Modifies the stack limit for this Isolate.
+   *
+   * \param stack_limit An address beyond which the Vm's stack may not grow.
+   *
+   * \note  If you are using threads then you should hold the V8::Locker lock
+   *     while setting the stack limit and you must set a non-default stack
+   *     limit separately for each thread.
+   */
+  void SetStackLimit(uintptr_t stack_limit);
+
+  /**
+   * Returns a memory range that can potentially contain jitted code.
+   *
+   * On Win64, embedders are advised to install function table callbacks for
+   * these ranges, as default SEH won't be able to unwind through jitted code.
+   *
+   * The first page of the code range is reserved for the embedder and is
+   * committed, writable, and executable.
+   *
+   * Might be empty on other platforms.
+   *
+   * https://code.google.com/p/v8/issues/detail?id=3598
+   */
+  void GetCodeRange(void** start, size_t* length_in_bytes);
+
+  /** Set the callback to invoke in case of fatal errors. */
+  void SetFatalErrorHandler(FatalErrorCallback that);
+
+  /** Set the callback to invoke in case of OOM errors. */
+  void SetOOMErrorHandler(OOMErrorCallback that);
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  void SetAllowCodeGenerationFromStringsCallback(
+      AllowCodeGenerationFromStringsCallback callback);
+
+  /**
+   * Embedder over{ride|load} injection points for wasm APIs.
+   */
+  void SetWasmModuleCallback(ExtensionCallback callback);
+  void SetWasmCompileCallback(ExtensionCallback callback);
+  void SetWasmInstanceCallback(ExtensionCallback callback);
+  void SetWasmInstantiateCallback(ExtensionCallback callback);
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  bool IsDead();
+
+  /**
+   * Adds a message listener (errors only).
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  bool AddMessageListener(MessageCallback that,
+                          Local<Value> data = Local<Value>());
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   *
+   * A listener can listen for particular error levels by providing a mask.
+   */
+  bool AddMessageListenerWithErrorLevel(MessageCallback that,
+                                        int message_levels,
+                                        Local<Value> data = Local<Value>());
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  void RemoveMessageListeners(MessageCallback that);
+
+  /** Callback function for reporting failed access checks.*/
+  void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback);
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  void SetCaptureStackTraceForUncaughtExceptions(
+      bool capture, int frame_limit = 10,
+      StackTrace::StackTraceOptions options = StackTrace::kOverview);
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  void VisitExternalResources(ExternalResourceVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  void VisitHandlesForPartialDependence(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are weak to be marked as inactive if there is no
+   * pending activity for the handle.
+   */
+  void VisitWeakHandles(PersistentHandleVisitor* visitor);
+
+  /**
+   * Check if this isolate is in use.
+   * True if at least one thread Enter'ed this isolate.
+   */
+  bool IsInUse();
+
+  /**
+   * Set whether calling Atomics.wait (a function that may block) is allowed in
+   * this isolate. This can also be configured via
+   * CreateParams::allow_atomics_wait.
+   */
+  void SetAllowAtomicsWait(bool allow);
+
+  Isolate() = delete;
+  ~Isolate() = delete;
+  Isolate(const Isolate&) = delete;
+  Isolate& operator=(const Isolate&) = delete;
+  void* operator new(size_t size) = delete;
+  void operator delete(void*, size_t) = delete;
+
+ private:
+  template <class K, class V, class Traits>
+  friend class PersistentValueMapBase;
+
+  void ReportExternalAllocationLimitReached();
+};
+
+class V8_EXPORT StartupData {
+ public:
+  const char* data;
+  int raw_size;
+};
+
+
+/**
+ * EntropySource is used as a callback function when v8 needs a source
+ * of entropy.
+ */
+typedef bool (*EntropySource)(unsigned char* buffer, size_t length);
+
+/**
+ * ReturnAddressLocationResolver is used as a callback function when v8 is
+ * resolving the location of a return address on the stack. Profilers that
+ * change the return address on the stack can use this to resolve the stack
+ * location to whereever the profiler stashed the original return address.
+ *
+ * \param return_addr_location A location on stack where a machine
+ *    return address resides.
+ * \returns Either return_addr_location, or else a pointer to the profiler's
+ *    copy of the original return address.
+ *
+ * \note The resolver function must not cause garbage collection.
+ */
+typedef uintptr_t (*ReturnAddressLocationResolver)(
+    uintptr_t return_addr_location);
+
+
+/**
+ * Container class for static utility functions.
+ */
+class V8_EXPORT V8 {
+ public:
+  /** Set the callback to invoke in case of fatal errors. */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFatalErrorHandler(FatalErrorCallback that));
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void SetAllowCodeGenerationFromStringsCallback(
+                                 AllowCodeGenerationFromStringsCallback that));
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  V8_INLINE static V8_DEPRECATED("Use isolate version", bool IsDead());
+
+  /**
+   * Hand startup data to V8, in case the embedder has chosen to build
+   * V8 with external startup data.
+   *
+   * Note:
+   * - By default the startup data is linked into the V8 library, in which
+   *   case this function is not meaningful.
+   * - If this needs to be called, it needs to be called before V8
+   *   tries to make use of its built-ins.
+   * - To avoid unnecessary copies of data, V8 will point directly into the
+   *   given data blob, so pretty please keep it around until V8 exit.
+   * - Compression of the startup blob might be useful, but needs to
+   *   handled entirely on the embedders' side.
+   * - The call will abort if the data is invalid.
+   */
+  static void SetNativesDataBlob(StartupData* startup_blob);
+  static void SetSnapshotDataBlob(StartupData* startup_blob);
+
+  /**
+   * Bootstrap an isolate and a context from scratch to create a startup
+   * snapshot. Include the side-effects of running the optional script.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   */
+  static StartupData CreateSnapshotDataBlob(const char* embedded_source = NULL);
+
+  /**
+   * Bootstrap an isolate and a context from the cold startup blob, run the
+   * warm-up script to trigger code compilation. The side effects are then
+   * discarded. The resulting startup snapshot will include compiled code.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   * The argument startup blob is untouched.
+   */
+  static StartupData WarmUpSnapshotDataBlob(StartupData cold_startup_blob,
+                                            const char* warmup_source);
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool AddMessageListener(MessageCallback that,
+                              Local<Value> data = Local<Value>()));
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void RemoveMessageListeners(MessageCallback that));
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetCaptureStackTraceForUncaughtExceptions(
+          bool capture, int frame_limit = 10,
+          StackTrace::StackTraceOptions options = StackTrace::kOverview));
+
+  /**
+   * Sets V8 flags from a string.
+   */
+  static void SetFlagsFromString(const char* str, int length);
+
+  /**
+   * Sets V8 flags from the command line.
+   */
+  static void SetFlagsFromCommandLine(int* argc,
+                                      char** argv,
+                                      bool remove_flags);
+
+  /** Get the version string. */
+  static const char* GetVersion();
+
+  /** Callback function for reporting failed access checks.*/
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback));
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCPrologueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCPrologueCallback(GCCallback callback));
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCEpilogueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCEpilogueCallback(GCCallback callback));
+
+  /**
+   * Initializes V8. This function needs to be called before the first Isolate
+   * is created. It always returns true.
+   */
+  static bool Initialize();
+
+  /**
+   * Allows the host application to provide a callback which can be used
+   * as a source of entropy for random number generators.
+   */
+  static void SetEntropySource(EntropySource source);
+
+  /**
+   * Allows the host application to provide a callback that allows v8 to
+   * cooperate with a profiler that rewrites return addresses on stack.
+   */
+  static void SetReturnAddressLocationResolver(
+      ReturnAddressLocationResolver return_address_resolver);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to terminate the current JS execution.
+   */
+  V8_INLINE static V8_DEPRECATED("Use isolate version",
+                                 void TerminateExecution(Isolate* isolate));
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   *
+   * \param isolate The isolate in which to check.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool IsExecutionTerminating(Isolate* isolate = NULL));
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to resume execution capability.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void CancelTerminateExecution(Isolate* isolate));
+
+  /**
+   * Releases any resources used by v8 and stops any utility threads
+   * that may be running.  Note that disposing v8 is permanent, it
+   * cannot be reinitialized.
+   *
+   * It should generally not be necessary to dispose v8 before exiting
+   * a process, this should happen automatically.  It is only necessary
+   * to use if the process needs the resources taken up by v8.
+   */
+  static bool Dispose();
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitExternalResources(ExternalResourceVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in isolate's heap that have
+   * class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(Isolate* isolate,
+                                    PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesForPartialDependence(Isolate* isolate,
+                                            PersistentHandleVisitor* visitor));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. Returns true on success.
+   *
+   * If V8 was compiled with the ICU data in an external file, the location
+   * of the data file has to be provided.
+   */
+  V8_DEPRECATE_SOON(
+      "Use version with default location.",
+      static bool InitializeICU(const char* icu_data_file = nullptr));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. If V8 was compiled with
+   * the ICU data in an external file and when the default location of that
+   * file should be used, a path to the executable must be provided.
+   * Returns true on success.
+   *
+   * The default is a file called icudtl.dat side-by-side with the executable.
+   *
+   * Optionally, the location of the data file can be provided to override the
+   * default.
+   */
+  static bool InitializeICUDefaultLocation(const char* exec_path,
+                                           const char* icu_data_file = nullptr);
+
+  /**
+   * Initialize the external startup data. The embedder only needs to
+   * invoke this method when external startup data was enabled in a build.
+   *
+   * If V8 was compiled with the startup data in an external file, then
+   * V8 needs to be given those external files during startup. There are
+   * three ways to do this:
+   * - InitializeExternalStartupData(const char*)
+   *   This will look in the given directory for files "natives_blob.bin"
+   *   and "snapshot_blob.bin" - which is what the default build calls them.
+   * - InitializeExternalStartupData(const char*, const char*)
+   *   As above, but will directly use the two given file names.
+   * - Call SetNativesDataBlob, SetNativesDataBlob.
+   *   This will read the blobs from the given data structures and will
+   *   not perform any file IO.
+   */
+  static void InitializeExternalStartupData(const char* directory_path);
+  static void InitializeExternalStartupData(const char* natives_blob,
+                                            const char* snapshot_blob);
+  /**
+   * Sets the v8::Platform to use. This should be invoked before V8 is
+   * initialized.
+   */
+  static void InitializePlatform(Platform* platform);
+
+  /**
+   * Clears all references to the v8::Platform. This should be invoked after
+   * V8 was disposed.
+   */
+  static void ShutdownPlatform();
+
+#if V8_OS_LINUX && V8_TARGET_ARCH_X64 && !V8_OS_ANDROID
+  /**
+   * Give the V8 signal handler a chance to handle a fault.
+   *
+   * This function determines whether a memory access violation can be recovered
+   * by V8. If so, it will return true and modify context to return to a code
+   * fragment that can recover from the fault. Otherwise, TryHandleSignal will
+   * return false.
+   *
+   * The parameters to this function correspond to those passed to a Linux
+   * signal handler.
+   *
+   * \param signal_number The signal number.
+   *
+   * \param info A pointer to the siginfo_t structure provided to the signal
+   * handler.
+   *
+   * \param context The third argument passed to the Linux signal handler, which
+   * points to a ucontext_t structure.
+   */
+  static bool TryHandleSignal(int signal_number, void* info, void* context);
+#endif  // V8_OS_LINUX
+
+  /**
+   * Enable the default signal handler rather than using one provided by the
+   * embedder.
+   */
+  static bool RegisterDefaultSignalHandler();
+
+ private:
+  V8();
+
+  static internal::Object** GlobalizeReference(internal::Isolate* isolate,
+                                               internal::Object** handle);
+  static internal::Object** CopyPersistent(internal::Object** handle);
+  static void DisposeGlobal(internal::Object** global_handle);
+  static void MakeWeak(internal::Object** location, void* data,
+                       WeakCallbackInfo<void>::Callback weak_callback,
+                       WeakCallbackType type);
+  static void MakeWeak(internal::Object** location, void* data,
+                       // Must be 0 or -1.
+                       int internal_field_index1,
+                       // Must be 1 or -1.
+                       int internal_field_index2,
+                       WeakCallbackInfo<void>::Callback weak_callback);
+  static void MakeWeak(internal::Object*** location_addr);
+  static void* ClearWeak(internal::Object** location);
+  static Value* Eternalize(Isolate* isolate, Value* handle);
+
+  static void RegisterExternallyReferencedObject(internal::Object** object,
+                                                 internal::Isolate* isolate);
+
+  template <class K, class V, class T>
+  friend class PersistentValueMapBase;
+
+  static void FromJustIsNothing();
+  static void ToLocalEmpty();
+  static void InternalFieldOutOfBounds(int index);
+  template <class T> friend class Local;
+  template <class T>
+  friend class MaybeLocal;
+  template <class T>
+  friend class Maybe;
+  template <class T>
+  friend class WeakCallbackInfo;
+  template <class T> friend class Eternal;
+  template <class T> friend class PersistentBase;
+  template <class T, class M> friend class Persistent;
+  friend class Context;
+};
+
+/**
+ * Helper class to create a snapshot data blob.
+ */
+class V8_EXPORT SnapshotCreator {
+ public:
+  enum class FunctionCodeHandling { kClear, kKeep };
+
+  /**
+   * Create and enter an isolate, and set it up for serialization.
+   * The isolate is either created from scratch or from an existing snapshot.
+   * The caller keeps ownership of the argument snapshot.
+   * \param existing_blob existing snapshot from which to create this one.
+   * \param external_references a null-terminated array of external references
+   *        that must be equivalent to CreateParams::external_references.
+   */
+  SnapshotCreator(intptr_t* external_references = nullptr,
+                  StartupData* existing_blob = nullptr);
+
+  ~SnapshotCreator();
+
+  /**
+   * \returns the isolate prepared by the snapshot creator.
+   */
+  Isolate* GetIsolate();
+
+  /**
+   * Set the default context to be included in the snapshot blob.
+   * The snapshot will not contain the global proxy, and we expect one or a
+   * global object template to create one, to be provided upon deserialization.
+   */
+  void SetDefaultContext(Local<Context> context);
+
+  /**
+   * Add additional context to be included in the snapshot blob.
+   * The snapshot will include the global proxy.
+   *
+   * \param callback optional callback to serialize internal fields.
+   *
+   * \returns the index of the context in the snapshot blob.
+   */
+  size_t AddContext(Local<Context> context,
+                    SerializeInternalFieldsCallback callback =
+                        SerializeInternalFieldsCallback());
+
+  /**
+   * Add a template to be included in the snapshot blob.
+   * \returns the index of the template in the snapshot blob.
+   */
+  size_t AddTemplate(Local<Template> template_obj);
+
+  /**
+   * Created a snapshot data blob.
+   * This must not be called from within a handle scope.
+   * \param function_code_handling whether to include compiled function code
+   *        in the snapshot.
+   * \returns { nullptr, 0 } on failure, and a startup snapshot on success. The
+   *        caller acquires ownership of the data array in the return value.
+   */
+  StartupData CreateBlob(FunctionCodeHandling function_code_handling);
+
+  // Disallow copying and assigning.
+  SnapshotCreator(const SnapshotCreator&) = delete;
+  void operator=(const SnapshotCreator&) = delete;
+
+ private:
+  void* data_;
+};
+
+/**
+ * A simple Maybe type, representing an object which may or may not have a
+ * value, see https://hackage.haskell.org/package/base/docs/Data-Maybe.html.
+ *
+ * If an API method returns a Maybe<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, a
+ * "Nothing" value is returned.
+ */
+template <class T>
+class Maybe {
+ public:
+  V8_INLINE bool IsNothing() const { return !has_value_; }
+  V8_INLINE bool IsJust() const { return has_value_; }
+
+  /**
+   * An alias for |FromJust|. Will crash if the Maybe<> is nothing.
+   */
+  V8_INLINE T ToChecked() const { return FromJust(); }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), |false| is returned and |out| is left untouched.
+   */
+  V8_WARN_UNUSED_RESULT V8_INLINE bool To(T* out) const {
+    if (V8_LIKELY(IsJust())) *out = value_;
+    return IsJust();
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), V8 will crash the process.
+   */
+  V8_INLINE T FromJust() const {
+    if (V8_UNLIKELY(!IsJust())) V8::FromJustIsNothing();
+    return value_;
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T, using a default value if this
+   * Maybe<> is nothing (empty).
+   */
+  V8_INLINE T FromMaybe(const T& default_value) const {
+    return has_value_ ? value_ : default_value;
+  }
+
+  V8_INLINE bool operator==(const Maybe& other) const {
+    return (IsJust() == other.IsJust()) &&
+           (!IsJust() || FromJust() == other.FromJust());
+  }
+
+  V8_INLINE bool operator!=(const Maybe& other) const {
+    return !operator==(other);
+  }
+
+ private:
+  Maybe() : has_value_(false) {}
+  explicit Maybe(const T& t) : has_value_(true), value_(t) {}
+
+  bool has_value_;
+  T value_;
+
+  template <class U>
+  friend Maybe<U> Nothing();
+  template <class U>
+  friend Maybe<U> Just(const U& u);
+};
+
+
+template <class T>
+inline Maybe<T> Nothing() {
+  return Maybe<T>();
+}
+
+
+template <class T>
+inline Maybe<T> Just(const T& t) {
+  return Maybe<T>(t);
+}
+
+
+/**
+ * An external exception handler.
+ */
+class V8_EXPORT TryCatch {
+ public:
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  V8_DEPRECATED("Use isolate version", TryCatch());
+
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  TryCatch(Isolate* isolate);
+
+  /**
+   * Unregisters and deletes this try/catch block.
+   */
+  ~TryCatch();
+
+  /**
+   * Returns true if an exception has been caught by this try/catch block.
+   */
+  bool HasCaught() const;
+
+  /**
+   * For certain types of exceptions, it makes no sense to continue execution.
+   *
+   * If CanContinue returns false, the correct action is to perform any C++
+   * cleanup needed and then return.  If CanContinue returns false and
+   * HasTerminated returns true, it is possible to call
+   * CancelTerminateExecution in order to continue calling into the engine.
+   */
+  bool CanContinue() const;
+
+  /**
+   * Returns true if an exception has been caught due to script execution
+   * being terminated.
+   *
+   * There is no JavaScript representation of an execution termination
+   * exception.  Such exceptions are thrown when the TerminateExecution
+   * methods are called to terminate a long-running script.
+   *
+   * If such an exception has been thrown, HasTerminated will return true,
+   * indicating that it is possible to call CancelTerminateExecution in order
+   * to continue calling into the engine.
+   */
+  bool HasTerminated() const;
+
+  /**
+   * Throws the exception caught by this TryCatch in a way that avoids
+   * it being caught again by this same TryCatch.  As with ThrowException
+   * it is illegal to execute any JavaScript operations after calling
+   * ReThrow; the caller must return immediately to where the exception
+   * is caught.
+   */
+  Local<Value> ReThrow();
+
+  /**
+   * Returns the exception caught by this try/catch block.  If no exception has
+   * been caught an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been destroyed.
+   */
+  Local<Value> Exception() const;
+
+  /**
+   * Returns the .stack property of the thrown object.  If no .stack
+   * property is present an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON("Use maybe version.", Local<Value> StackTrace() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> StackTrace(
+      Local<Context> context) const;
+
+  /**
+   * Returns the message associated with this exception.  If there is
+   * no message associated an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been
+   * destroyed.
+   */
+  Local<v8::Message> Message() const;
+
+  /**
+   * Clears any exceptions that may have been caught by this try/catch block.
+   * After this method has been called, HasCaught() will return false. Cancels
+   * the scheduled exception if it is caught and ReThrow() is not called before.
+   *
+   * It is not necessary to clear a try/catch block before using it again; if
+   * another exception is thrown the previously caught exception will just be
+   * overwritten.  However, it is often a good idea since it makes it easier
+   * to determine which operation threw a given exception.
+   */
+  void Reset();
+
+  /**
+   * Set verbosity of the external exception handler.
+   *
+   * By default, exceptions that are caught by an external exception
+   * handler are not reported.  Call SetVerbose with true on an
+   * external exception handler to have exceptions caught by the
+   * handler reported as if they were not caught.
+   */
+  void SetVerbose(bool value);
+
+  /**
+   * Returns true if verbosity is enabled.
+   */
+  bool IsVerbose() const;
+
+  /**
+   * Set whether or not this TryCatch should capture a Message object
+   * which holds source information about where the exception
+   * occurred.  True by default.
+   */
+  void SetCaptureMessage(bool value);
+
+  /**
+   * There are cases when the raw address of C++ TryCatch object cannot be
+   * used for comparisons with addresses into the JS stack. The cases are:
+   * 1) ARM, ARM64 and MIPS simulators which have separate JS stack.
+   * 2) Address sanitizer allocates local C++ object in the heap when
+   *    UseAfterReturn mode is enabled.
+   * This method returns address that can be used for comparisons with
+   * addresses into the JS stack. When neither simulator nor ASAN's
+   * UseAfterReturn is enabled, then the address returned will be the address
+   * of the C++ try catch handler itself.
+   */
+  static void* JSStackComparableAddress(TryCatch* handler) {
+    if (handler == NULL) return NULL;
+    return handler->js_stack_comparable_address_;
+  }
+
+  TryCatch(const TryCatch&) = delete;
+  void operator=(const TryCatch&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  void ResetInternal();
+
+  internal::Isolate* isolate_;
+  TryCatch* next_;
+  void* exception_;
+  void* message_obj_;
+  void* js_stack_comparable_address_;
+  bool is_verbose_ : 1;
+  bool can_continue_ : 1;
+  bool capture_message_ : 1;
+  bool rethrow_ : 1;
+  bool has_terminated_ : 1;
+
+  friend class internal::Isolate;
+};
+
+
+// --- Context ---
+
+
+/**
+ * A container for extension names.
+ */
+class V8_EXPORT ExtensionConfiguration {
+ public:
+  ExtensionConfiguration() : name_count_(0), names_(NULL) { }
+  ExtensionConfiguration(int name_count, const char* names[])
+      : name_count_(name_count), names_(names) { }
+
+  const char** begin() const { return &names_[0]; }
+  const char** end()  const { return &names_[name_count_]; }
+
+ private:
+  const int name_count_;
+  const char** names_;
+};
+
+/**
+ * A sandboxed execution context with its own set of built-in objects
+ * and functions.
+ */
+class V8_EXPORT Context {
+ public:
+  /**
+   * Returns the global proxy object.
+   *
+   * Global proxy object is a thin wrapper whose prototype points to actual
+   * context's global object with the properties like Object, etc. This is done
+   * that way for security reasons (for more details see
+   * https://wiki.mozilla.org/Gecko:SplitWindow).
+   *
+   * Please note that changes to global proxy object prototype most probably
+   * would break VM---v8 expects only global object as a prototype of global
+   * proxy object.
+   */
+  Local<Object> Global();
+
+  /**
+   * Detaches the global object from its context before
+   * the global object can be reused to create a new context.
+   */
+  void DetachGlobal();
+
+  /**
+   * Creates a new context and returns a handle to the newly allocated
+   * context.
+   *
+   * \param isolate The isolate in which to create the context.
+   *
+   * \param extensions An optional extension configuration containing
+   * the extensions to be installed in the newly created context.
+   *
+   * \param global_template An optional object template from which the
+   * global object for the newly created context will be created.
+   *
+   * \param global_object An optional global object to be reused for
+   * the newly created context. This global object must have been
+   * created by a previous call to Context::New with the same global
+   * template. The state of the global object will be completely reset
+   * and only object identify will remain.
+   */
+  static Local<Context> New(
+      Isolate* isolate, ExtensionConfiguration* extensions = NULL,
+      MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Create a new context from a (non-default) context snapshot. There
+   * is no way to provide a global object template since we do not create
+   * a new global object from template, but we can reuse a global object.
+   *
+   * \param isolate See v8::Context::New.
+   *
+   * \param context_snapshot_index The index of the context snapshot to
+   * deserialize from. Use v8::Context::New for the default snapshot.
+   *
+   * \param embedder_fields_deserializer Optional callback to deserialize
+   * internal fields. It should match the SerializeInternalFieldCallback used
+   * to serialize.
+   *
+   * \param extensions See v8::Context::New.
+   *
+   * \param global_object See v8::Context::New.
+   */
+
+  static MaybeLocal<Context> FromSnapshot(
+      Isolate* isolate, size_t context_snapshot_index,
+      DeserializeInternalFieldsCallback embedder_fields_deserializer =
+          DeserializeInternalFieldsCallback(),
+      ExtensionConfiguration* extensions = nullptr,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Returns an global object that isn't backed by an actual context.
+   *
+   * The global template needs to have access checks with handlers installed.
+   * If an existing global object is passed in, the global object is detached
+   * from its context.
+   *
+   * Note that this is different from a detached context where all accesses to
+   * the global proxy will fail. Instead, the access check handlers are invoked.
+   *
+   * It is also not possible to detach an object returned by this method.
+   * Instead, the access check handlers need to return nothing to achieve the
+   * same effect.
+   *
+   * It is possible, however, to create a new context from the global object
+   * returned by this method.
+   */
+  static MaybeLocal<Object> NewRemoteContext(
+      Isolate* isolate, Local<ObjectTemplate> global_template,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Sets the security token for the context.  To access an object in
+   * another context, the security tokens must match.
+   */
+  void SetSecurityToken(Local<Value> token);
+
+  /** Restores the security token to the default value. */
+  void UseDefaultSecurityToken();
+
+  /** Returns the security token of this context.*/
+  Local<Value> GetSecurityToken();
+
+  /**
+   * Enter this context.  After entering a context, all code compiled
+   * and run is compiled and run in this context.  If another context
+   * is already entered, this old context is saved so it can be
+   * restored when the new context is exited.
+   */
+  void Enter();
+
+  /**
+   * Exit this context.  Exiting the current context restores the
+   * context that was in place when entering the current context.
+   */
+  void Exit();
+
+  /** Returns an isolate associated with a current context. */
+  Isolate* GetIsolate();
+
+  /**
+   * The field at kDebugIdIndex used to be reserved for the inspector.
+   * It now serves no purpose.
+   */
+  enum EmbedderDataFields { kDebugIdIndex = 0 };
+
+  /**
+   * Gets the embedder data with the given index, which must have been set by a
+   * previous call to SetEmbedderData with the same index.
+   */
+  V8_INLINE Local<Value> GetEmbedderData(int index);
+
+  /**
+   * Gets the binding object used by V8 extras. Extra natives get a reference
+   * to this object and can use it to "export" functionality by adding
+   * properties. Extra natives can also "import" functionality by accessing
+   * properties added by the embedder using the V8 API.
+   */
+  Local<Object> GetExtrasBindingObject();
+
+  /**
+   * Sets the embedder data with the given index, growing the data as
+   * needed. Note that index 0 currently has a special meaning for Chrome's
+   * debugger.
+   */
+  void SetEmbedderData(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from the embedder data with the given
+   * index, which must have been set by a previous call to
+   * SetAlignedPointerInEmbedderData with the same index. Note that index 0
+   * currently has a special meaning for Chrome's debugger.
+   */
+  V8_INLINE void* GetAlignedPointerFromEmbedderData(int index);
+
+  /**
+   * Sets a 2-byte-aligned native pointer in the embedder data with the given
+   * index, growing the data as needed. Note that index 0 currently has a
+   * special meaning for Chrome's debugger.
+   */
+  void SetAlignedPointerInEmbedderData(int index, void* value);
+
+  /**
+   * Control whether code generation from strings is allowed. Calling
+   * this method with false will disable 'eval' and the 'Function'
+   * constructor for code running in this context. If 'eval' or the
+   * 'Function' constructor are used an exception will be thrown.
+   *
+   * If code generation from strings is not allowed the
+   * V8::AllowCodeGenerationFromStrings callback will be invoked if
+   * set before blocking the call to 'eval' or the 'Function'
+   * constructor. If that callback returns true, the call will be
+   * allowed, otherwise an exception will be thrown. If no callback is
+   * set an exception will be thrown.
+   */
+  void AllowCodeGenerationFromStrings(bool allow);
+
+  /**
+   * Returns true if code generation from strings is allowed for the context.
+   * For more details see AllowCodeGenerationFromStrings(bool) documentation.
+   */
+  bool IsCodeGenerationFromStringsAllowed();
+
+  /**
+   * Sets the error description for the exception that is thrown when
+   * code generation from strings is not allowed and 'eval' or the 'Function'
+   * constructor are called.
+   */
+  void SetErrorMessageForCodeGenerationFromStrings(Local<String> message);
+
+  /**
+   * Estimate the memory in bytes retained by this context.
+   */
+  V8_DEPRECATED("no longer supported", size_t EstimatedSize());
+
+  /**
+   * Stack-allocated class which sets the execution context for all
+   * operations executed within a local scope.
+   */
+  class Scope {
+   public:
+    explicit V8_INLINE Scope(Local<Context> context) : context_(context) {
+      context_->Enter();
+    }
+    V8_INLINE ~Scope() { context_->Exit(); }
+
+   private:
+    Local<Context> context_;
+  };
+
+ private:
+  friend class Value;
+  friend class Script;
+  friend class Object;
+  friend class Function;
+
+  Local<Value> SlowGetEmbedderData(int index);
+  void* SlowGetAlignedPointerFromEmbedderData(int index);
+};
+
+
+/**
+ * Multiple threads in V8 are allowed, but only one thread at a time is allowed
+ * to use any given V8 isolate, see the comments in the Isolate class. The
+ * definition of 'using a V8 isolate' includes accessing handles or holding onto
+ * object pointers obtained from V8 handles while in the particular V8 isolate.
+ * It is up to the user of V8 to ensure, perhaps with locking, that this
+ * constraint is not violated. In addition to any other synchronization
+ * mechanism that may be used, the v8::Locker and v8::Unlocker classes must be
+ * used to signal thread switches to V8.
+ *
+ * v8::Locker is a scoped lock object. While it's active, i.e. between its
+ * construction and destruction, the current thread is allowed to use the locked
+ * isolate. V8 guarantees that an isolate can be locked by at most one thread at
+ * any time. In other words, the scope of a v8::Locker is a critical section.
+ *
+ * Sample usage:
+* \code
+ * ...
+ * {
+ *   v8::Locker locker(isolate);
+ *   v8::Isolate::Scope isolate_scope(isolate);
+ *   ...
+ *   // Code using V8 and isolate goes here.
+ *   ...
+ * } // Destructor called here
+ * \endcode
+ *
+ * If you wish to stop using V8 in a thread A you can do this either by
+ * destroying the v8::Locker object as above or by constructing a v8::Unlocker
+ * object:
+ *
+ * \code
+ * {
+ *   isolate->Exit();
+ *   v8::Unlocker unlocker(isolate);
+ *   ...
+ *   // Code not using V8 goes here while V8 can run in another thread.
+ *   ...
+ * } // Destructor called here.
+ * isolate->Enter();
+ * \endcode
+ *
+ * The Unlocker object is intended for use in a long-running callback from V8,
+ * where you want to release the V8 lock for other threads to use.
+ *
+ * The v8::Locker is a recursive lock, i.e. you can lock more than once in a
+ * given thread. This can be useful if you have code that can be called either
+ * from code that holds the lock or from code that does not. The Unlocker is
+ * not recursive so you can not have several Unlockers on the stack at once, and
+ * you can not use an Unlocker in a thread that is not inside a Locker's scope.
+ *
+ * An unlocker will unlock several lockers if it has to and reinstate the
+ * correct depth of locking on its destruction, e.g.:
+ *
+ * \code
+ * // V8 not locked.
+ * {
+ *   v8::Locker locker(isolate);
+ *   Isolate::Scope isolate_scope(isolate);
+ *   // V8 locked.
+ *   {
+ *     v8::Locker another_locker(isolate);
+ *     // V8 still locked (2 levels).
+ *     {
+ *       isolate->Exit();
+ *       v8::Unlocker unlocker(isolate);
+ *       // V8 not locked.
+ *     }
+ *     isolate->Enter();
+ *     // V8 locked again (2 levels).
+ *   }
+ *   // V8 still locked (1 level).
+ * }
+ * // V8 Now no longer locked.
+ * \endcode
+ */
+class V8_EXPORT Unlocker {
+ public:
+  /**
+   * Initialize Unlocker for a given Isolate.
+   */
+  V8_INLINE explicit Unlocker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Unlocker();
+ private:
+  void Initialize(Isolate* isolate);
+
+  internal::Isolate* isolate_;
+};
+
+
+class V8_EXPORT Locker {
+ public:
+  /**
+   * Initialize Locker for a given Isolate.
+   */
+  V8_INLINE explicit Locker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Locker();
+
+  /**
+   * Returns whether or not the locker for a given isolate, is locked by the
+   * current thread.
+   */
+  static bool IsLocked(Isolate* isolate);
+
+  /**
+   * Returns whether v8::Locker is being used by this V8 instance.
+   */
+  static bool IsActive();
+
+  // Disallow copying and assigning.
+  Locker(const Locker&) = delete;
+  void operator=(const Locker&) = delete;
+
+ private:
+  void Initialize(Isolate* isolate);
+
+  bool has_lock_;
+  bool top_level_;
+  internal::Isolate* isolate_;
+};
+
+
+// --- Implementation ---
+
+
+namespace internal {
+
+const int kApiPointerSize = sizeof(void*);  // NOLINT
+const int kApiIntSize = sizeof(int);  // NOLINT
+const int kApiInt64Size = sizeof(int64_t);  // NOLINT
+
+// Tag information for HeapObject.
+const int kHeapObjectTag = 1;
+const int kHeapObjectTagSize = 2;
+const intptr_t kHeapObjectTagMask = (1 << kHeapObjectTagSize) - 1;
+
+// Tag information for Smi.
+const int kSmiTag = 0;
+const int kSmiTagSize = 1;
+const intptr_t kSmiTagMask = (1 << kSmiTagSize) - 1;
+
+template <size_t ptr_size> struct SmiTagging;
+
+template<int kSmiShiftSize>
+V8_INLINE internal::Object* IntToSmi(int value) {
+  int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
+  uintptr_t tagged_value =
+      (static_cast<uintptr_t>(value) << smi_shift_bits) | kSmiTag;
+  return reinterpret_cast<internal::Object*>(tagged_value);
+}
+
+// Smi constants for 32-bit systems.
+template <> struct SmiTagging<4> {
+  enum { kSmiShiftSize = 0, kSmiValueSize = 31 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Throw away top 32 bits and shift down (requires >> to be sign extending).
+    return static_cast<int>(reinterpret_cast<intptr_t>(value)) >> shift_bits;
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as an tagged small integer, the two
+    // most-significant bits of 'value' must be either 00 or 11 due to
+    // sign-extension. To check this we add 01 to the two
+    // most-significant bits, and check if the most-significant bit is 0
+    //
+    // CAUTION: The original code below:
+    // bool result = ((value + 0x40000000) & 0x80000000) == 0;
+    // may lead to incorrect results according to the C language spec, and
+    // in fact doesn't work correctly with gcc4.1.1 in some cases: The
+    // compiler may produce undefined results in case of signed integer
+    // overflow. The computation must be done w/ unsigned ints.
+    return static_cast<uintptr_t>(value + 0x40000000U) < 0x80000000U;
+  }
+};
+
+// Smi constants for 64-bit systems.
+template <> struct SmiTagging<8> {
+  enum { kSmiShiftSize = 31, kSmiValueSize = 32 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Shift down and throw away top 32 bits.
+    return static_cast<int>(reinterpret_cast<intptr_t>(value) >> shift_bits);
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as a long smi, the value must be a 32-bit integer.
+    return (value == static_cast<int32_t>(value));
+  }
+};
+
+typedef SmiTagging<kApiPointerSize> PlatformSmiTagging;
+const int kSmiShiftSize = PlatformSmiTagging::kSmiShiftSize;
+const int kSmiValueSize = PlatformSmiTagging::kSmiValueSize;
+V8_INLINE static bool SmiValuesAre31Bits() { return kSmiValueSize == 31; }
+V8_INLINE static bool SmiValuesAre32Bits() { return kSmiValueSize == 32; }
+
+/**
+ * This class exports constants and functionality from within v8 that
+ * is necessary to implement inline functions in the v8 api.  Don't
+ * depend on functions and constants defined here.
+ */
+class Internals {
+ public:
+  // These values match non-compiler-dependent values defined within
+  // the implementation of v8.
+  static const int kHeapObjectMapOffset = 0;
+  static const int kMapInstanceTypeAndBitFieldOffset =
+      1 * kApiPointerSize + kApiIntSize;
+  static const int kStringResourceOffset = 3 * kApiPointerSize;
+
+  static const int kOddballKindOffset = 4 * kApiPointerSize + sizeof(double);
+  static const int kForeignAddressOffset = kApiPointerSize;
+  static const int kJSObjectHeaderSize = 3 * kApiPointerSize;
+  static const int kFixedArrayHeaderSize = 2 * kApiPointerSize;
+  static const int kContextHeaderSize = 2 * kApiPointerSize;
+  static const int kContextEmbedderDataIndex = 5;
+  static const int kFullStringRepresentationMask = 0x0f;
+  static const int kStringEncodingMask = 0x8;
+  static const int kExternalTwoByteRepresentationTag = 0x02;
+  static const int kExternalOneByteRepresentationTag = 0x0a;
+
+  static const int kIsolateEmbedderDataOffset = 0 * kApiPointerSize;
+  static const int kExternalMemoryOffset = 4 * kApiPointerSize;
+  static const int kExternalMemoryLimitOffset =
+      kExternalMemoryOffset + kApiInt64Size;
+  static const int kIsolateRootsOffset = kExternalMemoryLimitOffset +
+                                         kApiInt64Size + kApiInt64Size +
+                                         kApiPointerSize + kApiPointerSize;
+  static const int kUndefinedValueRootIndex = 4;
+  static const int kTheHoleValueRootIndex = 5;
+  static const int kNullValueRootIndex = 6;
+  static const int kTrueValueRootIndex = 7;
+  static const int kFalseValueRootIndex = 8;
+  static const int kEmptyStringRootIndex = 9;
+
+  static const int kNodeClassIdOffset = 1 * kApiPointerSize;
+  static const int kNodeFlagsOffset = 1 * kApiPointerSize + 3;
+  static const int kNodeStateMask = 0x7;
+  static const int kNodeStateIsWeakValue = 2;
+  static const int kNodeStateIsPendingValue = 3;
+  static const int kNodeStateIsNearDeathValue = 4;
+  static const int kNodeIsIndependentShift = 3;
+  static const int kNodeIsActiveShift = 4;
+
+  static const int kJSApiObjectType = 0xbb;
+  static const int kJSObjectType = 0xbc;
+  static const int kFirstNonstringType = 0x80;
+  static const int kOddballType = 0x82;
+  static const int kForeignType = 0x86;
+
+  static const int kUndefinedOddballKind = 5;
+  static const int kNullOddballKind = 3;
+
+  static const uint32_t kNumIsolateDataSlots = 4;
+
+  V8_EXPORT static void CheckInitializedImpl(v8::Isolate* isolate);
+  V8_INLINE static void CheckInitialized(v8::Isolate* isolate) {
+#ifdef V8_ENABLE_CHECKS
+    CheckInitializedImpl(isolate);
+#endif
+  }
+
+  V8_INLINE static bool HasHeapObjectTag(const internal::Object* value) {
+    return ((reinterpret_cast<intptr_t>(value) & kHeapObjectTagMask) ==
+            kHeapObjectTag);
+  }
+
+  V8_INLINE static int SmiValue(const internal::Object* value) {
+    return PlatformSmiTagging::SmiToInt(value);
+  }
+
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return PlatformSmiTagging::IntToSmi(value);
+  }
+
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    return PlatformSmiTagging::IsValidSmi(value);
+  }
+
+  V8_INLINE static int GetInstanceType(const internal::Object* obj) {
+    typedef internal::Object O;
+    O* map = ReadField<O*>(obj, kHeapObjectMapOffset);
+    // Map::InstanceType is defined so that it will always be loaded into
+    // the LS 8 bits of one 16-bit word, regardless of endianess.
+    return ReadField<uint16_t>(map, kMapInstanceTypeAndBitFieldOffset) & 0xff;
+  }
+
+  V8_INLINE static int GetOddballKind(const internal::Object* obj) {
+    typedef internal::Object O;
+    return SmiValue(ReadField<O*>(obj, kOddballKindOffset));
+  }
+
+  V8_INLINE static bool IsExternalTwoByteString(int instance_type) {
+    int representation = (instance_type & kFullStringRepresentationMask);
+    return representation == kExternalTwoByteRepresentationTag;
+  }
+
+  V8_INLINE static uint8_t GetNodeFlag(internal::Object** obj, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      return *addr & static_cast<uint8_t>(1U << shift);
+  }
+
+  V8_INLINE static void UpdateNodeFlag(internal::Object** obj,
+                                       bool value, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      uint8_t mask = static_cast<uint8_t>(1U << shift);
+      *addr = static_cast<uint8_t>((*addr & ~mask) | (value << shift));
+  }
+
+  V8_INLINE static uint8_t GetNodeState(internal::Object** obj) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    return *addr & kNodeStateMask;
+  }
+
+  V8_INLINE static void UpdateNodeState(internal::Object** obj,
+                                        uint8_t value) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    *addr = static_cast<uint8_t>((*addr & ~kNodeStateMask) | value);
+  }
+
+  V8_INLINE static void SetEmbedderData(v8::Isolate* isolate,
+                                        uint32_t slot,
+                                        void* data) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) +
+                    kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    *reinterpret_cast<void**>(addr) = data;
+  }
+
+  V8_INLINE static void* GetEmbedderData(const v8::Isolate* isolate,
+                                         uint32_t slot) {
+    const uint8_t* addr = reinterpret_cast<const uint8_t*>(isolate) +
+        kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    return *reinterpret_cast<void* const*>(addr);
+  }
+
+  V8_INLINE static internal::Object** GetRoot(v8::Isolate* isolate,
+                                              int index) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) + kIsolateRootsOffset;
+    return reinterpret_cast<internal::Object**>(addr + index * kApiPointerSize);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadField(const internal::Object* ptr, int offset) {
+    const uint8_t* addr =
+        reinterpret_cast<const uint8_t*>(ptr) + offset - kHeapObjectTag;
+    return *reinterpret_cast<const T*>(addr);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadEmbedderData(const v8::Context* context, int index) {
+    typedef internal::Object O;
+    typedef internal::Internals I;
+    O* ctx = *reinterpret_cast<O* const*>(context);
+    int embedder_data_offset = I::kContextHeaderSize +
+        (internal::kApiPointerSize * I::kContextEmbedderDataIndex);
+    O* embedder_data = I::ReadField<O*>(ctx, embedder_data_offset);
+    int value_offset =
+        I::kFixedArrayHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<T>(embedder_data, value_offset);
+  }
+};
+
+}  // namespace internal
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, Local<T> that) {
+  return New(isolate, that.val_);
+}
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, const PersistentBase<T>& that) {
+  return New(isolate, that.val_);
+}
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return Local<T>();
+  T* that_ptr = that;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that_ptr);
+  return Local<T>(reinterpret_cast<T*>(HandleScope::CreateHandle(
+      reinterpret_cast<internal::Isolate*>(isolate), *p)));
+}
+
+
+template<class T>
+template<class S>
+void Eternal<T>::Set(Isolate* isolate, Local<S> handle) {
+  TYPE_CHECK(T, S);
+  val_ = reinterpret_cast<T*>(
+      V8::Eternalize(isolate, reinterpret_cast<Value*>(*handle)));
+}
+
+template <class T>
+Local<T> Eternal<T>::Get(Isolate* isolate) const {
+  // The eternal handle will never go away, so as with the roots, we don't even
+  // need to open a handle.
+  return Local<T>(val_);
+}
+
+
+template <class T>
+Local<T> MaybeLocal<T>::ToLocalChecked() {
+  if (V8_UNLIKELY(val_ == nullptr)) V8::ToLocalEmpty();
+  return Local<T>(val_);
+}
+
+
+template <class T>
+void* WeakCallbackInfo<T>::GetInternalField(int index) const {
+#ifdef V8_ENABLE_CHECKS
+  if (index < 0 || index >= kEmbedderFieldsInWeakCallback) {
+    V8::InternalFieldOutOfBounds(index);
+  }
+#endif
+  return embedder_fields_[index];
+}
+
+
+template <class T>
+T* PersistentBase<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return NULL;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that);
+  return reinterpret_cast<T*>(
+      V8::GlobalizeReference(reinterpret_cast<internal::Isolate*>(isolate),
+                             p));
+}
+
+
+template <class T, class M>
+template <class S, class M2>
+void Persistent<T, M>::Copy(const Persistent<S, M2>& that) {
+  TYPE_CHECK(T, S);
+  this->Reset();
+  if (that.IsEmpty()) return;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that.val_);
+  this->val_ = reinterpret_cast<T*>(V8::CopyPersistent(p));
+  M::Copy(that, this);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsIndependent() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                        I::kNodeIsIndependentShift);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsNearDeath() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  uint8_t node_state =
+      I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_));
+  return node_state == I::kNodeStateIsNearDeathValue ||
+      node_state == I::kNodeStateIsPendingValue;
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsWeak() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_)) ==
+      I::kNodeStateIsWeakValue;
+}
+
+
+template <class T>
+void PersistentBase<T>::Reset() {
+  if (this->IsEmpty()) return;
+  V8::DisposeGlobal(reinterpret_cast<internal::Object**>(this->val_));
+  val_ = 0;
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate, const Local<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate,
+                              const PersistentBase<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <typename P>
+V8_INLINE void PersistentBase<T>::SetWeak(
+    P* parameter, typename WeakCallbackInfo<P>::Callback callback,
+    WeakCallbackType type) {
+  typedef typename WeakCallbackInfo<void>::Callback Callback;
+  V8::MakeWeak(reinterpret_cast<internal::Object**>(this->val_), parameter,
+               reinterpret_cast<Callback>(callback), type);
+}
+
+template <class T>
+void PersistentBase<T>::SetWeak() {
+  V8::MakeWeak(reinterpret_cast<internal::Object***>(&this->val_));
+}
+
+template <class T>
+template <typename P>
+P* PersistentBase<T>::ClearWeak() {
+  return reinterpret_cast<P*>(
+    V8::ClearWeak(reinterpret_cast<internal::Object**>(this->val_)));
+}
+
+template <class T>
+void PersistentBase<T>::RegisterExternalReference(Isolate* isolate) const {
+  if (IsEmpty()) return;
+  V8::RegisterExternallyReferencedObject(
+      reinterpret_cast<internal::Object**>(this->val_),
+      reinterpret_cast<internal::Isolate*>(isolate));
+}
+
+template <class T>
+void PersistentBase<T>::MarkIndependent() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                    true,
+                    I::kNodeIsIndependentShift);
+}
+
+template <class T>
+void PersistentBase<T>::MarkActive() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_), true,
+                    I::kNodeIsActiveShift);
+}
+
+
+template <class T>
+void PersistentBase<T>::SetWrapperClassId(uint16_t class_id) {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  *reinterpret_cast<uint16_t*>(addr) = class_id;
+}
+
+
+template <class T>
+uint16_t PersistentBase<T>::WrapperClassId() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return 0;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  return *reinterpret_cast<uint16_t*>(addr);
+}
+
+
+template<typename T>
+ReturnValue<T>::ReturnValue(internal::Object** slot) : value_(slot) {}
+
+template<typename T>
+template<typename S>
+void ReturnValue<T>::Set(const Persistent<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Global<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Local<S> handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template<typename T>
+void ReturnValue<T>::Set(double i) {
+  TYPE_CHECK(T, Number);
+  Set(Number::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(int32_t i) {
+  TYPE_CHECK(T, Integer);
+  typedef internal::Internals I;
+  if (V8_LIKELY(I::IsValidSmi(i))) {
+    *value_ = I::IntToSmi(i);
+    return;
+  }
+  Set(Integer::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(uint32_t i) {
+  TYPE_CHECK(T, Integer);
+  // Can't simply use INT32_MAX here for whatever reason.
+  bool fits_into_int32_t = (i & (1U << 31)) == 0;
+  if (V8_LIKELY(fits_into_int32_t)) {
+    Set(static_cast<int32_t>(i));
+    return;
+  }
+  Set(Integer::NewFromUnsigned(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(bool value) {
+  TYPE_CHECK(T, Boolean);
+  typedef internal::Internals I;
+  int root_index;
+  if (value) {
+    root_index = I::kTrueValueRootIndex;
+  } else {
+    root_index = I::kFalseValueRootIndex;
+  }
+  *value_ = *I::GetRoot(GetIsolate(), root_index);
+}
+
+template<typename T>
+void ReturnValue<T>::SetNull() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kNullValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetUndefined() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kUndefinedValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetEmptyString() {
+  TYPE_CHECK(T, String);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kEmptyStringRootIndex);
+}
+
+template <typename T>
+Isolate* ReturnValue<T>::GetIsolate() const {
+  // Isolate is always the pointer below the default value on the stack.
+  return *reinterpret_cast<Isolate**>(&value_[-2]);
+}
+
+template <typename T>
+Local<Value> ReturnValue<T>::Get() const {
+  typedef internal::Internals I;
+  if (*value_ == *I::GetRoot(GetIsolate(), I::kTheHoleValueRootIndex))
+    return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>::New(GetIsolate(), reinterpret_cast<Value*>(value_));
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(S* whatever) {
+  // Uncompilable to prevent inadvertent misuse.
+  TYPE_CHECK(S*, Primitive);
+}
+
+template<typename T>
+internal::Object* ReturnValue<T>::GetDefaultValue() {
+  // Default value is always the pointer below value_ on the stack.
+  return value_[-1];
+}
+
+template <typename T>
+FunctionCallbackInfo<T>::FunctionCallbackInfo(internal::Object** implicit_args,
+                                              internal::Object** values,
+                                              int length)
+    : implicit_args_(implicit_args), values_(values), length_(length) {}
+
+template<typename T>
+Local<Value> FunctionCallbackInfo<T>::operator[](int i) const {
+  if (i < 0 || length_ <= i) return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>(reinterpret_cast<Value*>(values_ - i));
+}
+
+
+template<typename T>
+Local<Function> FunctionCallbackInfo<T>::Callee() const {
+  return Local<Function>(reinterpret_cast<Function*>(
+      &implicit_args_[kCalleeIndex]));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(
+      &implicit_args_[kHolderIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::NewTarget() const {
+  return Local<Value>(
+      reinterpret_cast<Value*>(&implicit_args_[kNewTargetIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&implicit_args_[kDataIndex]));
+}
+
+
+template<typename T>
+Isolate* FunctionCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&implicit_args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+ReturnValue<T> FunctionCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&implicit_args_[kReturnValueIndex]);
+}
+
+
+template<typename T>
+bool FunctionCallbackInfo<T>::IsConstructCall() const {
+  return !NewTarget()->IsUndefined();
+}
+
+
+template<typename T>
+int FunctionCallbackInfo<T>::Length() const {
+  return length_;
+}
+
+ScriptOrigin::ScriptOrigin(Local<Value> resource_name,
+                           Local<Integer> resource_line_offset,
+                           Local<Integer> resource_column_offset,
+                           Local<Boolean> resource_is_shared_cross_origin,
+                           Local<Integer> script_id,
+                           Local<Value> source_map_url,
+                           Local<Boolean> resource_is_opaque,
+                           Local<Boolean> is_wasm, Local<Boolean> is_module)
+    : resource_name_(resource_name),
+      resource_line_offset_(resource_line_offset),
+      resource_column_offset_(resource_column_offset),
+      options_(!resource_is_shared_cross_origin.IsEmpty() &&
+                   resource_is_shared_cross_origin->IsTrue(),
+               !resource_is_opaque.IsEmpty() && resource_is_opaque->IsTrue(),
+               !is_wasm.IsEmpty() && is_wasm->IsTrue(),
+               !is_module.IsEmpty() && is_module->IsTrue()),
+      script_id_(script_id),
+      source_map_url_(source_map_url) {}
+
+Local<Value> ScriptOrigin::ResourceName() const { return resource_name_; }
+
+
+Local<Integer> ScriptOrigin::ResourceLineOffset() const {
+  return resource_line_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ResourceColumnOffset() const {
+  return resource_column_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ScriptID() const { return script_id_; }
+
+
+Local<Value> ScriptOrigin::SourceMapUrl() const { return source_map_url_; }
+
+
+ScriptCompiler::Source::Source(Local<String> string, const ScriptOrigin& origin,
+                               CachedData* data)
+    : source_string(string),
+      resource_name(origin.ResourceName()),
+      resource_line_offset(origin.ResourceLineOffset()),
+      resource_column_offset(origin.ResourceColumnOffset()),
+      resource_options(origin.Options()),
+      source_map_url(origin.SourceMapUrl()),
+      cached_data(data) {}
+
+
+ScriptCompiler::Source::Source(Local<String> string,
+                               CachedData* data)
+    : source_string(string), cached_data(data) {}
+
+
+ScriptCompiler::Source::~Source() {
+  delete cached_data;
+}
+
+
+const ScriptCompiler::CachedData* ScriptCompiler::Source::GetCachedData()
+    const {
+  return cached_data;
+}
+
+const ScriptOriginOptions& ScriptCompiler::Source::GetResourceOptions() const {
+  return resource_options;
+}
+
+Local<Boolean> Boolean::New(Isolate* isolate, bool value) {
+  return value ? True(isolate) : False(isolate);
+}
+
+void Template::Set(Isolate* isolate, const char* name, Local<Data> value) {
+  Set(String::NewFromUtf8(isolate, name, NewStringType::kInternalized)
+          .ToLocalChecked(),
+      value);
+}
+
+
+Local<Value> Object::GetInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (instance_type == I::kJSObjectType ||
+      instance_type == I::kJSApiObjectType) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    O* value = I::ReadField<O*>(obj, offset);
+    O** result = HandleScope::CreateHandle(reinterpret_cast<HO*>(obj), value);
+    return Local<Value>(reinterpret_cast<Value*>(result));
+  }
+#endif
+  return SlowGetInternalField(index);
+}
+
+
+void* Object::GetAlignedPointerFromInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (V8_LIKELY(instance_type == I::kJSObjectType ||
+                instance_type == I::kJSApiObjectType)) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<void*>(obj, offset);
+  }
+#endif
+  return SlowGetAlignedPointerFromInternalField(index);
+}
+
+String* String::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<String*>(value);
+}
+
+
+Local<String> String::Empty(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kEmptyStringRootIndex);
+  return Local<String>(reinterpret_cast<String*>(slot));
+}
+
+
+String::ExternalStringResource* String::GetExternalStringResource() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  String::ExternalStringResource* result;
+  if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    result = reinterpret_cast<String::ExternalStringResource*>(value);
+  } else {
+    result = NULL;
+  }
+#ifdef V8_ENABLE_CHECKS
+  VerifyExternalStringResource(result);
+#endif
+  return result;
+}
+
+
+String::ExternalStringResourceBase* String::GetExternalStringResourceBase(
+    String::Encoding* encoding_out) const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  int type = I::GetInstanceType(obj) & I::kFullStringRepresentationMask;
+  *encoding_out = static_cast<Encoding>(type & I::kStringEncodingMask);
+  ExternalStringResourceBase* resource = NULL;
+  if (type == I::kExternalOneByteRepresentationTag ||
+      type == I::kExternalTwoByteRepresentationTag) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    resource = static_cast<ExternalStringResourceBase*>(value);
+  }
+#ifdef V8_ENABLE_CHECKS
+    VerifyExternalStringResourceBase(resource, *encoding_out);
+#endif
+  return resource;
+}
+
+
+bool Value::IsUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsUndefined();
+#else
+  return QuickIsUndefined();
+#endif
+}
+
+bool Value::QuickIsUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kUndefinedOddballKind);
+}
+
+
+bool Value::IsNull() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull();
+#else
+  return QuickIsNull();
+#endif
+}
+
+bool Value::QuickIsNull() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kNullOddballKind);
+}
+
+bool Value::IsNullOrUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull() || FullIsUndefined();
+#else
+  return QuickIsNullOrUndefined();
+#endif
+}
+
+bool Value::QuickIsNullOrUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  int kind = I::GetOddballKind(obj);
+  return kind == I::kNullOddballKind || kind == I::kUndefinedOddballKind;
+}
+
+bool Value::IsString() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsString();
+#else
+  return QuickIsString();
+#endif
+}
+
+bool Value::QuickIsString() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  return (I::GetInstanceType(obj) < I::kFirstNonstringType);
+}
+
+
+template <class T> Value* Value::Cast(T* value) {
+  return static_cast<Value*>(value);
+}
+
+
+Local<Boolean> Value::ToBoolean() const {
+  return ToBoolean(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Boolean>());
+}
+
+
+Local<Number> Value::ToNumber() const {
+  return ToNumber(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Number>());
+}
+
+
+Local<String> Value::ToString() const {
+  return ToString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<String> Value::ToDetailString() const {
+  return ToDetailString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<Object> Value::ToObject() const {
+  return ToObject(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Object>());
+}
+
+
+Local<Integer> Value::ToInteger() const {
+  return ToInteger(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Integer>());
+}
+
+
+Local<Uint32> Value::ToUint32() const {
+  return ToUint32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Uint32>());
+}
+
+
+Local<Int32> Value::ToInt32() const {
+  return ToInt32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Int32>());
+}
+
+
+Boolean* Boolean::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Boolean*>(value);
+}
+
+
+Name* Name::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Name*>(value);
+}
+
+
+Symbol* Symbol::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Symbol*>(value);
+}
+
+
+Number* Number::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Number*>(value);
+}
+
+
+Integer* Integer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Integer*>(value);
+}
+
+
+Int32* Int32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32*>(value);
+}
+
+
+Uint32* Uint32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32*>(value);
+}
+
+
+Date* Date::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Date*>(value);
+}
+
+
+StringObject* StringObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<StringObject*>(value);
+}
+
+
+SymbolObject* SymbolObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SymbolObject*>(value);
+}
+
+
+NumberObject* NumberObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<NumberObject*>(value);
+}
+
+
+BooleanObject* BooleanObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<BooleanObject*>(value);
+}
+
+
+RegExp* RegExp::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<RegExp*>(value);
+}
+
+
+Object* Object::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Object*>(value);
+}
+
+
+Array* Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Array*>(value);
+}
+
+
+Map* Map::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Map*>(value);
+}
+
+
+Set* Set::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Set*>(value);
+}
+
+
+Promise* Promise::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise*>(value);
+}
+
+
+Proxy* Proxy::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Proxy*>(value);
+}
+
+WasmCompiledModule* WasmCompiledModule::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<WasmCompiledModule*>(value);
+}
+
+Promise::Resolver* Promise::Resolver::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise::Resolver*>(value);
+}
+
+
+ArrayBuffer* ArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBuffer*>(value);
+}
+
+
+ArrayBufferView* ArrayBufferView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBufferView*>(value);
+}
+
+
+TypedArray* TypedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<TypedArray*>(value);
+}
+
+
+Uint8Array* Uint8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8Array*>(value);
+}
+
+
+Int8Array* Int8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int8Array*>(value);
+}
+
+
+Uint16Array* Uint16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint16Array*>(value);
+}
+
+
+Int16Array* Int16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int16Array*>(value);
+}
+
+
+Uint32Array* Uint32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32Array*>(value);
+}
+
+
+Int32Array* Int32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32Array*>(value);
+}
+
+
+Float32Array* Float32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float32Array*>(value);
+}
+
+
+Float64Array* Float64Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float64Array*>(value);
+}
+
+
+Uint8ClampedArray* Uint8ClampedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8ClampedArray*>(value);
+}
+
+
+DataView* DataView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<DataView*>(value);
+}
+
+
+SharedArrayBuffer* SharedArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedArrayBuffer*>(value);
+}
+
+
+Function* Function::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Function*>(value);
+}
+
+
+External* External::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<External*>(value);
+}
+
+
+template<typename T>
+Isolate* PropertyCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+Local<Value> PropertyCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&args_[kDataIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kThisIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kHolderIndex]));
+}
+
+
+template<typename T>
+ReturnValue<T> PropertyCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&args_[kReturnValueIndex]);
+}
+
+template <typename T>
+bool PropertyCallbackInfo<T>::ShouldThrowOnError() const {
+  typedef internal::Internals I;
+  return args_[kShouldThrowOnErrorIndex] != I::IntToSmi(0);
+}
+
+
+Local<Primitive> Undefined(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kUndefinedValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Primitive> Null(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kNullValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Boolean> True(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kTrueValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+Local<Boolean> False(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kFalseValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+void Isolate::SetData(uint32_t slot, void* data) {
+  typedef internal::Internals I;
+  I::SetEmbedderData(this, slot, data);
+}
+
+
+void* Isolate::GetData(uint32_t slot) {
+  typedef internal::Internals I;
+  return I::GetEmbedderData(this, slot);
+}
+
+
+uint32_t Isolate::GetNumberOfDataSlots() {
+  typedef internal::Internals I;
+  return I::kNumIsolateDataSlots;
+}
+
+
+int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
+    int64_t change_in_bytes) {
+  typedef internal::Internals I;
+  int64_t* external_memory = reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryOffset);
+  const int64_t external_memory_limit = *reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryLimitOffset);
+  const int64_t amount = *external_memory + change_in_bytes;
+  *external_memory = amount;
+  if (change_in_bytes > 0 && amount > external_memory_limit) {
+    ReportExternalAllocationLimitReached();
+  }
+  return *external_memory;
+}
+
+Local<Value> Context::GetEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  HO* context = *reinterpret_cast<HO**>(this);
+  O** result =
+      HandleScope::CreateHandle(context, I::ReadEmbedderData<O*>(this, index));
+  return Local<Value>(reinterpret_cast<Value*>(result));
+#else
+  return SlowGetEmbedderData(index);
+#endif
+}
+
+
+void* Context::GetAlignedPointerFromEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Internals I;
+  return I::ReadEmbedderData<void*>(this, index);
+#else
+  return SlowGetAlignedPointerFromEmbedderData(index);
+#endif
+}
+
+
+void V8::SetAllowCodeGenerationFromStringsCallback(
+    AllowCodeGenerationFromStringsCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetAllowCodeGenerationFromStringsCallback(callback);
+}
+
+
+bool V8::IsDead() {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->IsDead();
+}
+
+
+bool V8::AddMessageListener(MessageCallback that, Local<Value> data) {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->AddMessageListener(that, data);
+}
+
+
+void V8::RemoveMessageListeners(MessageCallback that) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveMessageListeners(that);
+}
+
+
+void V8::SetFailedAccessCheckCallbackFunction(
+    FailedAccessCheckCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFailedAccessCheckCallbackFunction(callback);
+}
+
+
+void V8::SetCaptureStackTraceForUncaughtExceptions(
+    bool capture, int frame_limit, StackTrace::StackTraceOptions options) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetCaptureStackTraceForUncaughtExceptions(capture, frame_limit,
+                                                     options);
+}
+
+
+void V8::SetFatalErrorHandler(FatalErrorCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFatalErrorHandler(callback);
+}
+
+void V8::RemoveGCPrologueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCPrologueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+
+void V8::RemoveGCEpilogueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCEpilogueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+void V8::TerminateExecution(Isolate* isolate) { isolate->TerminateExecution(); }
+
+
+bool V8::IsExecutionTerminating(Isolate* isolate) {
+  if (isolate == NULL) {
+    isolate = Isolate::GetCurrent();
+  }
+  return isolate->IsExecutionTerminating();
+}
+
+
+void V8::CancelTerminateExecution(Isolate* isolate) {
+  isolate->CancelTerminateExecution();
+}
+
+
+void V8::VisitExternalResources(ExternalResourceVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitExternalResources(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(PersistentHandleVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(Isolate* isolate,
+                                  PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesForPartialDependence(Isolate* isolate,
+                                          PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesForPartialDependence(visitor);
+}
+
+/**
+ * \example shell.cc
+ * A simple shell that takes a list of expressions on the
+ * command-line and executes them.
+ */
+
+
+/**
+ * \example process.cc
+ */
+
+
+}  // namespace v8
+
+
+#undef TYPE_CHECK
+
+
+#endif  // INCLUDE_V8_H_
diff --git a/android/armeabi/include/v8/v8config.h b/android/armeabi/include/v8/v8config.h
new file mode 100644
index 00000000..964949c2
--- /dev/null
+++ b/android/armeabi/include/v8/v8config.h
@@ -0,0 +1,428 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8CONFIG_H_
+#define V8CONFIG_H_
+
+// clang-format off
+
+// Platform headers for feature detection below.
+#if defined(__ANDROID__)
+# include <sys/cdefs.h>
+#elif defined(__APPLE__)
+# include <TargetConditionals.h>
+#elif defined(__linux__)
+# include <features.h>
+#endif
+
+
+// This macro allows to test for the version of the GNU C library (or
+// a compatible C library that masquerades as glibc). It evaluates to
+// 0 if libc is not GNU libc or compatible.
+// Use like:
+//  #if V8_GLIBC_PREREQ(2, 3)
+//   ...
+//  #endif
+#if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
+# define V8_GLIBC_PREREQ(major, minor)                                    \
+    ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
+#else
+# define V8_GLIBC_PREREQ(major, minor) 0
+#endif
+
+
+// This macro allows to test for the version of the GNU C++ compiler.
+// Note that this also applies to compilers that masquerade as GCC,
+// for example clang and the Intel C++ compiler for Linux.
+// Use like:
+//  #if V8_GNUC_PREREQ(4, 3, 1)
+//   ...
+//  #endif
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)                         \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >=   \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)      \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >=      \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#else
+# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
+#endif
+
+
+
+// -----------------------------------------------------------------------------
+// Operating system detection
+//
+//  V8_OS_ANDROID       - Android
+//  V8_OS_BSD           - BSDish (Mac OS X, Net/Free/Open/DragonFlyBSD)
+//  V8_OS_CYGWIN        - Cygwin
+//  V8_OS_DRAGONFLYBSD  - DragonFlyBSD
+//  V8_OS_FREEBSD       - FreeBSD
+//  V8_OS_LINUX         - Linux
+//  V8_OS_MACOSX        - Mac OS X
+//  V8_OS_NETBSD        - NetBSD
+//  V8_OS_OPENBSD       - OpenBSD
+//  V8_OS_POSIX         - POSIX compatible (mostly everything except Windows)
+//  V8_OS_QNX           - QNX Neutrino
+//  V8_OS_SOLARIS       - Sun Solaris and OpenSolaris
+//  V8_OS_AIX           - AIX
+//  V8_OS_WIN           - Microsoft Windows
+
+#if defined(__ANDROID__)
+# define V8_OS_ANDROID 1
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__APPLE__)
+# define V8_OS_BSD 1
+# define V8_OS_MACOSX 1
+# define V8_OS_POSIX 1
+#elif defined(__CYGWIN__)
+# define V8_OS_CYGWIN 1
+# define V8_OS_POSIX 1
+#elif defined(__linux__)
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__sun)
+# define V8_OS_POSIX 1
+# define V8_OS_SOLARIS 1
+#elif defined(_AIX)
+#define V8_OS_POSIX 1
+#define V8_OS_AIX 1
+#elif defined(__FreeBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_FREEBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__DragonFly__)
+# define V8_OS_BSD 1
+# define V8_OS_DRAGONFLYBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__NetBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_NETBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__OpenBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_OPENBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__QNXNTO__)
+# define V8_OS_POSIX 1
+# define V8_OS_QNX 1
+#elif defined(_WIN32)
+# define V8_OS_WIN 1
+#endif
+
+
+// -----------------------------------------------------------------------------
+// C library detection
+//
+//  V8_LIBC_MSVCRT  - MSVC libc
+//  V8_LIBC_BIONIC  - Bionic libc
+//  V8_LIBC_BSD     - BSD libc derivate
+//  V8_LIBC_GLIBC   - GNU C library
+//  V8_LIBC_UCLIBC  - uClibc
+//
+// Note that testing for libc must be done using #if not #ifdef. For example,
+// to test for the GNU C library, use:
+//  #if V8_LIBC_GLIBC
+//   ...
+//  #endif
+
+#if defined (_MSC_VER)
+# define V8_LIBC_MSVCRT 1
+#elif defined(__BIONIC__)
+# define V8_LIBC_BIONIC 1
+# define V8_LIBC_BSD 1
+#elif defined(__UCLIBC__)
+// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
+# define V8_LIBC_UCLIBC 1
+#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
+# define V8_LIBC_GLIBC 1
+#else
+# define V8_LIBC_BSD V8_OS_BSD
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Compiler detection
+//
+//  V8_CC_GNU     - GCC, or clang in gcc mode
+//  V8_CC_INTEL   - Intel C++
+//  V8_CC_MINGW   - Minimalist GNU for Windows
+//  V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
+//  V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
+//  V8_CC_MSVC    - Microsoft Visual C/C++, or clang in cl.exe mode
+//
+// C++11 feature detection
+//
+//  V8_HAS_CXX11_ALIGNAS        - alignas specifier supported
+//  V8_HAS_CXX11_ALIGNOF        - alignof(type) operator supported
+//
+// Compiler-specific feature detection
+//
+//  V8_HAS___ALIGNOF                    - __alignof(type) operator supported
+//  V8_HAS___ALIGNOF__                  - __alignof__(type) operator supported
+//  V8_HAS_ATTRIBUTE_ALIGNED            - __attribute__((aligned(n))) supported
+//  V8_HAS_ATTRIBUTE_ALWAYS_INLINE      - __attribute__((always_inline))
+//                                        supported
+//  V8_HAS_ATTRIBUTE_DEPRECATED         - __attribute__((deprecated)) supported
+//  V8_HAS_ATTRIBUTE_NOINLINE           - __attribute__((noinline)) supported
+//  V8_HAS_ATTRIBUTE_NORETURN           - __attribute__((noreturn)) supported
+//  V8_HAS_ATTRIBUTE_UNUSED             - __attribute__((unused)) supported
+//  V8_HAS_ATTRIBUTE_VISIBILITY         - __attribute__((visibility)) supported
+//  V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
+//                                        supported
+//  V8_HAS_BUILTIN_CLZ                  - __builtin_clz() supported
+//  V8_HAS_BUILTIN_CTZ                  - __builtin_ctz() supported
+//  V8_HAS_BUILTIN_EXPECT               - __builtin_expect() supported
+//  V8_HAS_BUILTIN_FRAME_ADDRESS        - __builtin_frame_address() supported
+//  V8_HAS_BUILTIN_POPCOUNT             - __builtin_popcount() supported
+//  V8_HAS_BUILTIN_SADD_OVERFLOW        - __builtin_sadd_overflow() supported
+//  V8_HAS_BUILTIN_SSUB_OVERFLOW        - __builtin_ssub_overflow() supported
+//  V8_HAS_BUILTIN_UADD_OVERFLOW        - __builtin_uadd_overflow() supported
+//  V8_HAS_DECLSPEC_ALIGN               - __declspec(align(n)) supported
+//  V8_HAS_DECLSPEC_DEPRECATED          - __declspec(deprecated) supported
+//  V8_HAS_DECLSPEC_NOINLINE            - __declspec(noinline) supported
+//  V8_HAS_DECLSPEC_SELECTANY           - __declspec(selectany) supported
+//  V8_HAS_DECLSPEC_NORETURN            - __declspec(noreturn) supported
+//  V8_HAS___FORCEINLINE                - __forceinline supported
+//
+// Note that testing for compilers and/or features must be done using #if
+// not #ifdef. For example, to test for Intel C++ Compiler, use:
+//  #if V8_CC_INTEL
+//   ...
+//  #endif
+
+#if defined(__clang__)
+
+#if defined(__GNUC__)  // Clang in gcc mode.
+# define V8_CC_GNU 1
+#endif
+
+// Clang defines __alignof__ as alias for __alignof
+# define V8_HAS___ALIGNOF 1
+# define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
+# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
+# define V8_HAS_ATTRIBUTE_NORETURN (__has_attribute(noreturn))
+# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (__has_attribute(warn_unused_result))
+
+# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
+# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
+# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
+# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
+# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
+# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
+# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
+
+# define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
+
+#elif defined(__GNUC__)
+
+# define V8_CC_GNU 1
+# if defined(__INTEL_COMPILER)  // Intel C++ also masquerades as GCC 3.2.0
+#  define V8_CC_INTEL 1
+# endif
+# if defined(__MINGW32__)
+#  define V8_CC_MINGW32 1
+# endif
+# if defined(__MINGW64__)
+#  define V8_CC_MINGW64 1
+# endif
+# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
+
+# define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
+// always_inline is available in gcc 4.0 but not very reliable until 4.4.
+// Works around "sorry, unimplemented: inlining failed" build errors with
+// older compilers.
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (V8_GNUC_PREREQ(4, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
+# define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_NORETURN (V8_GNUC_PREREQ(2, 5, 0))
+# define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
+
+# define V8_HAS_BUILTIN_CLZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_CTZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
+
+# if __cplusplus >= 201103L
+#  define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
+#  define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
+# endif
+#endif
+
+#if defined(_MSC_VER)
+# define V8_CC_MSVC 1
+# define V8_HAS___ALIGNOF 1
+
+# define V8_HAS_DECLSPEC_ALIGN 1
+# define V8_HAS_DECLSPEC_DEPRECATED 1
+# define V8_HAS_DECLSPEC_NOINLINE 1
+# define V8_HAS_DECLSPEC_SELECTANY 1
+# define V8_HAS_DECLSPEC_NORETURN 1
+
+# define V8_HAS___FORCEINLINE 1
+
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Helper macros
+
+// A macro used to make better inlining. Don't bother for debug builds.
+// Use like:
+//   V8_INLINE int GetZero() { return 0; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
+# define V8_INLINE inline __attribute__((always_inline))
+#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
+# define V8_INLINE __forceinline
+#else
+# define V8_INLINE inline
+#endif
+
+
+// A macro used to tell the compiler to never inline a particular function.
+// Don't bother for debug builds.
+// Use like:
+//   V8_NOINLINE int GetMinusOne() { return -1; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
+# define V8_NOINLINE __attribute__((noinline))
+#elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
+# define V8_NOINLINE __declspec(noinline)
+#else
+# define V8_NOINLINE /* NOT SUPPORTED */
+#endif
+
+
+// A macro used to tell the compiler that a particular function never returns.
+// Use like:
+//   V8_NORETURN void MyAbort() { abort(); }
+#if V8_HAS_ATTRIBUTE_NORETURN
+# define V8_NORETURN __attribute__((noreturn))
+#elif V8_HAS_DECLSPEC_NORETURN
+# define V8_NORETURN __declspec(noreturn)
+#else
+# define V8_NORETURN /* NOT SUPPORTED */
+#endif
+
+
+// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
+#if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATED(message, declarator) declarator
+#endif
+
+
+// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
+#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) && \
+    V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATE_SOON(message, declarator) declarator
+#endif
+
+
+// A macro to provide the compiler with branch prediction information.
+#if V8_HAS_BUILTIN_EXPECT
+# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
+# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
+#else
+# define V8_UNLIKELY(condition) (condition)
+# define V8_LIKELY(condition) (condition)
+#endif
+
+
+// This macro allows to specify memory alignment for structs, classes, etc.
+// Use like:
+//   class V8_ALIGNED(16) MyClass { ... };
+//   V8_ALIGNED(32) int array[42];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNED(n) alignas(n)
+#elif V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNED(n) __attribute__((aligned(n)))
+#elif V8_HAS_DECLSPEC_ALIGN
+# define V8_ALIGNED(n) __declspec(align(n))
+#else
+# define V8_ALIGNED(n) /* NOT SUPPORTED */
+#endif
+
+
+// This macro is similar to V8_ALIGNED(), but takes a type instead of size
+// in bytes. If the compiler does not supports using the alignment of the
+// |type|, it will align according to the |alignment| instead. For example,
+// Visual Studio C++ cannot combine __declspec(align) and __alignof. The
+// |alignment| must be a literal that is used as a kind of worst-case fallback
+// alignment.
+// Use like:
+//   struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
+//   V8_ALIGNAS(double, 8) int array[100];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNAS(type, alignment) alignas(type)
+#elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
+#else
+# define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
+#endif
+
+
+// This macro returns alignment in bytes (an integer power of two) required for
+// any instance of the given type, which is either complete type, an array type,
+// or a reference type.
+// Use like:
+//   size_t alignment = V8_ALIGNOF(double);
+#if V8_HAS_CXX11_ALIGNOF
+# define V8_ALIGNOF(type) alignof(type)
+#elif V8_HAS___ALIGNOF
+# define V8_ALIGNOF(type) __alignof(type)
+#elif V8_HAS___ALIGNOF__
+# define V8_ALIGNOF(type) __alignof__(type)
+#else
+// Note that alignment of a type within a struct can be less than the
+// alignment of the type stand-alone (because of ancient ABIs), so this
+// should only be used as a last resort.
+namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
+# define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
+#endif
+
+// Annotate a function indicating the caller must examine the return value.
+// Use like:
+//   int foo() WARN_UNUSED_RESULT;
+#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
+#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
+#endif
+
+// clang-format on
+
+#endif  // V8CONFIG_H_
diff --git a/android/armeabi/libinspector.a b/android/armeabi/libinspector.a
new file mode 100644
index 00000000..a6da3e80
Binary files /dev/null and b/android/armeabi/libinspector.a differ
diff --git a/android/armeabi/libv8_base.a b/android/armeabi/libv8_base.a
new file mode 100644
index 00000000..3ca9e5a5
Binary files /dev/null and b/android/armeabi/libv8_base.a differ
diff --git a/android/armeabi/libv8_builtins_generators.a b/android/armeabi/libv8_builtins_generators.a
new file mode 100644
index 00000000..2343354e
Binary files /dev/null and b/android/armeabi/libv8_builtins_generators.a differ
diff --git a/android/armeabi/libv8_builtins_setup.a b/android/armeabi/libv8_builtins_setup.a
new file mode 100644
index 00000000..3328b78a
Binary files /dev/null and b/android/armeabi/libv8_builtins_setup.a differ
diff --git a/android/armeabi/libv8_libbase.a b/android/armeabi/libv8_libbase.a
new file mode 100644
index 00000000..d6047628
Binary files /dev/null and b/android/armeabi/libv8_libbase.a differ
diff --git a/android/armeabi/libv8_libplatform.a b/android/armeabi/libv8_libplatform.a
new file mode 100644
index 00000000..d20ee429
Binary files /dev/null and b/android/armeabi/libv8_libplatform.a differ
diff --git a/android/armeabi/libv8_libsampler.a b/android/armeabi/libv8_libsampler.a
new file mode 100644
index 00000000..137e0111
Binary files /dev/null and b/android/armeabi/libv8_libsampler.a differ
diff --git a/android/armeabi/libv8_nosnapshot.a b/android/armeabi/libv8_nosnapshot.a
new file mode 100644
index 00000000..d265bc9d
Binary files /dev/null and b/android/armeabi/libv8_nosnapshot.a differ
diff --git a/android/x86/include/v8/libplatform/libplatform-export.h b/android/x86/include/v8/libplatform/libplatform-export.h
new file mode 100644
index 00000000..15618434
--- /dev/null
+++ b/android/x86/include/v8/libplatform/libplatform-export.h
@@ -0,0 +1,29 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
+
+#if defined(_WIN32)
+
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllexport)
+#elif USING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __declspec(dllimport)
+#else
+#define V8_PLATFORM_EXPORT
+#endif  // BUILDING_V8_PLATFORM_SHARED
+
+#else  // defined(_WIN32)
+
+// Setup for Linux shared library export.
+#ifdef BUILDING_V8_PLATFORM_SHARED
+#define V8_PLATFORM_EXPORT __attribute__((visibility("default")))
+#else
+#define V8_PLATFORM_EXPORT
+#endif
+
+#endif  // defined(_WIN32)
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_EXPORT_H_
diff --git a/android/x86/include/v8/libplatform/libplatform.h b/android/x86/include/v8/libplatform/libplatform.h
new file mode 100644
index 00000000..e9450456
--- /dev/null
+++ b/android/x86/include/v8/libplatform/libplatform.h
@@ -0,0 +1,78 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_LIBPLATFORM_H_
+#define V8_LIBPLATFORM_LIBPLATFORM_H_
+
+#include "libplatform/libplatform-export.h"
+#include "libplatform/v8-tracing.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+namespace platform {
+
+enum class IdleTaskSupport { kDisabled, kEnabled };
+enum class InProcessStackDumping { kDisabled, kEnabled };
+
+enum class MessageLoopBehavior : bool {
+  kDoNotWait = false,
+  kWaitForWork = true
+};
+
+/**
+ * Returns a new instance of the default v8::Platform implementation.
+ *
+ * The caller will take ownership of the returned pointer. |thread_pool_size|
+ * is the number of worker threads to allocate for background jobs. If a value
+ * of zero is passed, a suitable default based on the current number of
+ * processors online will be chosen.
+ * If |idle_task_support| is enabled then the platform will accept idle
+ * tasks (IdleTasksEnabled will return true) and will rely on the embedder
+ * calling v8::platform::RunIdleTasks to process the idle tasks.
+ */
+V8_PLATFORM_EXPORT v8::Platform* CreateDefaultPlatform(
+    int thread_pool_size = 0,
+    IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
+    InProcessStackDumping in_process_stack_dumping =
+        InProcessStackDumping::kEnabled);
+
+/**
+ * Pumps the message loop for the given isolate.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * Returns true if a task was executed, and false otherwise. Unless requested
+ * through the |behavior| parameter, this call does not block if no task is
+ * pending. The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT bool PumpMessageLoop(
+    v8::Platform* platform, v8::Isolate* isolate,
+    MessageLoopBehavior behavior = MessageLoopBehavior::kDoNotWait);
+
+V8_PLATFORM_EXPORT void EnsureEventLoopInitialized(v8::Platform* platform,
+                                                   v8::Isolate* isolate);
+
+/**
+ * Runs pending idle tasks for at most |idle_time_in_seconds| seconds.
+ *
+ * The caller has to make sure that this is called from the right thread.
+ * This call does not block if no task is pending. The |platform| has to be
+ * created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void RunIdleTasks(v8::Platform* platform,
+                                     v8::Isolate* isolate,
+                                     double idle_time_in_seconds);
+
+/**
+ * Attempts to set the tracing controller for the given platform.
+ *
+ * The |platform| has to be created using |CreateDefaultPlatform|.
+ */
+V8_PLATFORM_EXPORT void SetTracingController(
+    v8::Platform* platform,
+    v8::platform::tracing::TracingController* tracing_controller);
+
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_LIBPLATFORM_H_
diff --git a/android/x86/include/v8/libplatform/v8-tracing.h b/android/x86/include/v8/libplatform/v8-tracing.h
new file mode 100644
index 00000000..902f8ea9
--- /dev/null
+++ b/android/x86/include/v8/libplatform/v8-tracing.h
@@ -0,0 +1,270 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LIBPLATFORM_V8_TRACING_H_
+#define V8_LIBPLATFORM_V8_TRACING_H_
+
+#include <fstream>
+#include <memory>
+#include <unordered_set>
+#include <vector>
+
+#include "libplatform/libplatform-export.h"
+#include "v8-platform.h"  // NOLINT(build/include)
+
+namespace v8 {
+
+namespace base {
+class Mutex;
+}  // namespace base
+
+namespace platform {
+namespace tracing {
+
+const int kTraceMaxNumArgs = 2;
+
+class V8_PLATFORM_EXPORT TraceObject {
+ public:
+  union ArgValue {
+    bool as_bool;
+    uint64_t as_uint;
+    int64_t as_int;
+    double as_double;
+    const void* as_pointer;
+    const char* as_string;
+  };
+
+  TraceObject() {}
+  ~TraceObject();
+  void Initialize(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateDuration();
+  void InitializeForTesting(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags, int pid, int tid, int64_t ts, int64_t tts,
+      uint64_t duration, uint64_t cpu_duration);
+
+  int pid() const { return pid_; }
+  int tid() const { return tid_; }
+  char phase() const { return phase_; }
+  const uint8_t* category_enabled_flag() const {
+    return category_enabled_flag_;
+  }
+  const char* name() const { return name_; }
+  const char* scope() const { return scope_; }
+  uint64_t id() const { return id_; }
+  uint64_t bind_id() const { return bind_id_; }
+  int num_args() const { return num_args_; }
+  const char** arg_names() { return arg_names_; }
+  uint8_t* arg_types() { return arg_types_; }
+  ArgValue* arg_values() { return arg_values_; }
+  std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables() {
+    return arg_convertables_;
+  }
+  unsigned int flags() const { return flags_; }
+  int64_t ts() { return ts_; }
+  int64_t tts() { return tts_; }
+  uint64_t duration() { return duration_; }
+  uint64_t cpu_duration() { return cpu_duration_; }
+
+ private:
+  int pid_;
+  int tid_;
+  char phase_;
+  const char* name_;
+  const char* scope_;
+  const uint8_t* category_enabled_flag_;
+  uint64_t id_;
+  uint64_t bind_id_;
+  int num_args_ = 0;
+  const char* arg_names_[kTraceMaxNumArgs];
+  uint8_t arg_types_[kTraceMaxNumArgs];
+  ArgValue arg_values_[kTraceMaxNumArgs];
+  std::unique_ptr<v8::ConvertableToTraceFormat>
+      arg_convertables_[kTraceMaxNumArgs];
+  char* parameter_copy_storage_ = nullptr;
+  unsigned int flags_;
+  int64_t ts_;
+  int64_t tts_;
+  uint64_t duration_;
+  uint64_t cpu_duration_;
+
+  // Disallow copy and assign
+  TraceObject(const TraceObject&) = delete;
+  void operator=(const TraceObject&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceWriter {
+ public:
+  TraceWriter() {}
+  virtual ~TraceWriter() {}
+  virtual void AppendTraceEvent(TraceObject* trace_event) = 0;
+  virtual void Flush() = 0;
+
+  static TraceWriter* CreateJSONTraceWriter(std::ostream& stream);
+
+ private:
+  // Disallow copy and assign
+  TraceWriter(const TraceWriter&) = delete;
+  void operator=(const TraceWriter&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBufferChunk {
+ public:
+  explicit TraceBufferChunk(uint32_t seq);
+
+  void Reset(uint32_t new_seq);
+  bool IsFull() const { return next_free_ == kChunkSize; }
+  TraceObject* AddTraceEvent(size_t* event_index);
+  TraceObject* GetEventAt(size_t index) { return &chunk_[index]; }
+
+  uint32_t seq() const { return seq_; }
+  size_t size() const { return next_free_; }
+
+  static const size_t kChunkSize = 64;
+
+ private:
+  size_t next_free_ = 0;
+  TraceObject chunk_[kChunkSize];
+  uint32_t seq_;
+
+  // Disallow copy and assign
+  TraceBufferChunk(const TraceBufferChunk&) = delete;
+  void operator=(const TraceBufferChunk&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TraceBuffer {
+ public:
+  TraceBuffer() {}
+  virtual ~TraceBuffer() {}
+
+  virtual TraceObject* AddTraceEvent(uint64_t* handle) = 0;
+  virtual TraceObject* GetEventByHandle(uint64_t handle) = 0;
+  virtual bool Flush() = 0;
+
+  static const size_t kRingBufferChunks = 1024;
+
+  static TraceBuffer* CreateTraceBufferRingBuffer(size_t max_chunks,
+                                                  TraceWriter* trace_writer);
+
+ private:
+  // Disallow copy and assign
+  TraceBuffer(const TraceBuffer&) = delete;
+  void operator=(const TraceBuffer&) = delete;
+};
+
+// Options determines how the trace buffer stores data.
+enum TraceRecordMode {
+  // Record until the trace buffer is full.
+  RECORD_UNTIL_FULL,
+
+  // Record until the user ends the trace. The trace buffer is a fixed size
+  // and we use it as a ring buffer during recording.
+  RECORD_CONTINUOUSLY,
+
+  // Record until the trace buffer is full, but with a huge buffer size.
+  RECORD_AS_MUCH_AS_POSSIBLE,
+
+  // Echo to console. Events are discarded.
+  ECHO_TO_CONSOLE,
+};
+
+class V8_PLATFORM_EXPORT TraceConfig {
+ public:
+  typedef std::vector<std::string> StringList;
+
+  static TraceConfig* CreateDefaultTraceConfig();
+
+  TraceConfig() : enable_systrace_(false), enable_argument_filter_(false) {}
+  TraceRecordMode GetTraceRecordMode() const { return record_mode_; }
+  bool IsSystraceEnabled() const { return enable_systrace_; }
+  bool IsArgumentFilterEnabled() const { return enable_argument_filter_; }
+
+  void SetTraceRecordMode(TraceRecordMode mode) { record_mode_ = mode; }
+  void EnableSystrace() { enable_systrace_ = true; }
+  void EnableArgumentFilter() { enable_argument_filter_ = true; }
+
+  void AddIncludedCategory(const char* included_category);
+
+  bool IsCategoryGroupEnabled(const char* category_group) const;
+
+ private:
+  TraceRecordMode record_mode_;
+  bool enable_systrace_ : 1;
+  bool enable_argument_filter_ : 1;
+  StringList included_categories_;
+
+  // Disallow copy and assign
+  TraceConfig(const TraceConfig&) = delete;
+  void operator=(const TraceConfig&) = delete;
+};
+
+class V8_PLATFORM_EXPORT TracingController {
+ public:
+  enum Mode { DISABLED = 0, RECORDING_MODE };
+
+  // The pointer returned from GetCategoryGroupEnabledInternal() points to a
+  // value with zero or more of the following bits. Used in this class only.
+  // The TRACE_EVENT macros should only use the value as a bool.
+  // These values must be in sync with macro values in TraceEvent.h in Blink.
+  enum CategoryGroupEnabledFlags {
+    // Category group enabled for the recording mode.
+    ENABLED_FOR_RECORDING = 1 << 0,
+    // Category group enabled by SetEventCallbackEnabled().
+    ENABLED_FOR_EVENT_CALLBACK = 1 << 2,
+    // Category group enabled to export events to ETW.
+    ENABLED_FOR_ETW_EXPORT = 1 << 3
+  };
+
+  TracingController();
+  ~TracingController();
+  void Initialize(TraceBuffer* trace_buffer);
+  const uint8_t* GetCategoryGroupEnabled(const char* category_group);
+  static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
+  uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags);
+  void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                const char* name, uint64_t handle);
+
+  void StartTracing(TraceConfig* trace_config);
+  void StopTracing();
+
+  void AddTraceStateObserver(Platform::TraceStateObserver* observer);
+  void RemoveTraceStateObserver(Platform::TraceStateObserver* observer);
+
+ private:
+  const uint8_t* GetCategoryGroupEnabledInternal(const char* category_group);
+  void UpdateCategoryGroupEnabledFlag(size_t category_index);
+  void UpdateCategoryGroupEnabledFlags();
+
+  std::unique_ptr<TraceBuffer> trace_buffer_;
+  std::unique_ptr<TraceConfig> trace_config_;
+  std::unique_ptr<base::Mutex> mutex_;
+  std::unordered_set<Platform::TraceStateObserver*> observers_;
+  Mode mode_ = DISABLED;
+
+  // Disallow copy and assign
+  TracingController(const TracingController&) = delete;
+  void operator=(const TracingController&) = delete;
+};
+
+}  // namespace tracing
+}  // namespace platform
+}  // namespace v8
+
+#endif  // V8_LIBPLATFORM_V8_TRACING_H_
diff --git a/android/x86/include/v8/v8-debug.h b/android/x86/include/v8/v8-debug.h
new file mode 100644
index 00000000..54c0f216
--- /dev/null
+++ b/android/x86/include/v8/v8-debug.h
@@ -0,0 +1,255 @@
+// Copyright 2008 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_DEBUG_H_
+#define V8_V8_DEBUG_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * ATTENTION: The debugger API exposed by this file is deprecated and will be
+ *            removed by the end of 2017. Please use the V8 inspector declared
+ *            in include/v8-inspector.h instead.
+ */
+namespace v8 {
+
+// Debug events which can occur in the V8 JavaScript engine.
+enum DebugEvent {
+  Break = 1,
+  Exception = 2,
+  AfterCompile = 3,
+  CompileError = 4,
+  AsyncTaskEvent = 5,
+};
+
+class V8_EXPORT Debug {
+ public:
+  /**
+   * A client object passed to the v8 debugger whose ownership will be taken by
+   * it. v8 is always responsible for deleting the object.
+   */
+  class ClientData {
+   public:
+    virtual ~ClientData() {}
+  };
+
+
+  /**
+   * A message object passed to the debug message handler.
+   */
+  class Message {
+   public:
+    /**
+     * Check type of message.
+     */
+    virtual bool IsEvent() const = 0;
+    virtual bool IsResponse() const = 0;
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Indicate whether this is a response to a continue command which will
+     * start the VM running after this is processed.
+     */
+    virtual bool WillStartRunning() const = 0;
+
+    /**
+     * Access to execution state and event data. Don't store these cross
+     * callbacks as their content becomes invalid. These objects are from the
+     * debugger event that started the debug message loop.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the debugger protocol JSON.
+     */
+    virtual Local<String> GetJSON() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding request if any. This is the
+     * client_data data value passed into Debug::SendCommand along with the
+     * request that led to the message or NULL if the message is an event. The
+     * debugger takes ownership of the data and will delete it even if there is
+     * no message handler.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~Message() {}
+  };
+
+  /**
+   * An event details object passed to the debug event listener.
+   */
+  class EventDetails {
+   public:
+    /**
+     * Event type.
+     */
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Access to execution state and event data of the debug event. Don't store
+     * these cross callbacks as their content becomes invalid.
+     */
+    virtual Local<Object> GetExecutionState() const = 0;
+    virtual Local<Object> GetEventData() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in its own context which is entered at this point.
+     */
+    virtual Local<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding callback when it was
+     * registered.
+     */
+    virtual Local<Value> GetCallbackData() const = 0;
+
+    /**
+     * This is now a dummy that returns nullptr.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual Isolate* GetIsolate() const = 0;
+
+    virtual ~EventDetails() {}
+  };
+
+  /**
+   * Debug event callback function.
+   *
+   * \param event_details object providing information about the debug event
+   *
+   * A EventCallback does not take possession of the event data,
+   * and must not rely on the data persisting after the handler returns.
+   */
+  typedef void (*EventCallback)(const EventDetails& event_details);
+
+  /**
+   * This is now a no-op.
+   */
+  typedef void (*MessageHandler)(const Message& message);
+
+  V8_DEPRECATED("No longer supported", static bool SetDebugEventListener(
+                                           Isolate* isolate, EventCallback that,
+                                           Local<Value> data = Local<Value>()));
+
+  // Schedule a debugger break to happen when JavaScript code is run
+  // in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static void DebugBreak(Isolate* isolate));
+
+  // Remove scheduled debugger break in given isolate if it has not
+  // happened yet.
+  V8_DEPRECATED("No longer supported",
+                static void CancelDebugBreak(Isolate* isolate));
+
+  // Check if a debugger break is scheduled in the given isolate.
+  V8_DEPRECATED("No longer supported",
+                static bool CheckDebugBreak(Isolate* isolate));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SetMessageHandler(Isolate* isolate,
+                                              MessageHandler handler));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void SendCommand(Isolate* isolate,
+                                        const uint16_t* command, int length,
+                                        ClientData* client_data = NULL));
+
+  /**
+   * Run a JavaScript function in the debugger.
+   * \param fun the function to call
+   * \param data passed as second argument to the function
+   * With this call the debugger is entered and the function specified is called
+   * with the execution state as the first argument. This makes it possible to
+   * get access to information otherwise not available during normal JavaScript
+   * execution e.g. details on stack frames. Receiver of the function call will
+   * be the debugger context global object, however this is a subject to change.
+   * The following example shows a JavaScript function which when passed to
+   * v8::Debug::Call will return the current line of JavaScript execution.
+   *
+   * \code
+   *   function frame_source_line(exec_state) {
+   *     return exec_state.frame(0).sourceLine();
+   *   }
+   * \endcode
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Value> Call(
+                    Local<Context> context, v8::Local<v8::Function> fun,
+                    Local<Value> data = Local<Value>()));
+
+  // This is now a no-op.
+  V8_DEPRECATED("No longer supported",
+                static void ProcessDebugMessages(Isolate* isolate));
+
+  /**
+   * Debugger is running in its own context which is entered while debugger
+   * messages are being dispatched. This is an explicit getter for this
+   * debugger context. Note that the content of the debugger context is subject
+   * to change. The Context exists only when the debugger is active, i.e. at
+   * least one DebugEventListener or MessageHandler is set.
+   */
+  V8_DEPRECATED("Use v8-inspector",
+                static Local<Context> GetDebugContext(Isolate* isolate));
+
+  /**
+   * While in the debug context, this method returns the top-most non-debug
+   * context, if it exists.
+   */
+  V8_DEPRECATED(
+      "No longer supported",
+      static MaybeLocal<Context> GetDebuggedContext(Isolate* isolate));
+
+  /**
+   * Enable/disable LiveEdit functionality for the given Isolate
+   * (default Isolate if not provided). V8 will abort if LiveEdit is
+   * unexpectedly used. LiveEdit is enabled by default.
+   */
+  V8_DEPRECATED("No longer supported",
+                static void SetLiveEditEnabled(Isolate* isolate, bool enable));
+
+  /**
+   * Returns array of internal properties specific to the value type. Result has
+   * the following format: [<name>, <value>,...,<name>, <value>]. Result array
+   * will be allocated in the current context.
+   */
+  V8_DEPRECATED("No longer supported",
+                static MaybeLocal<Array> GetInternalProperties(
+                    Isolate* isolate, Local<Value> value));
+
+  /**
+   * Defines if the ES2015 tail call elimination feature is enabled or not.
+   * The change of this flag triggers deoptimization of all functions that
+   * contain calls at tail position.
+   */
+  V8_DEPRECATED("No longer supported",
+                static bool IsTailCallEliminationEnabled(Isolate* isolate));
+  V8_DEPRECATED("No longer supported",
+                static void SetTailCallEliminationEnabled(Isolate* isolate,
+                                                          bool enabled));
+};
+
+
+}  // namespace v8
+
+
+#undef EXPORT
+
+
+#endif  // V8_V8_DEBUG_H_
diff --git a/android/x86/include/v8/v8-inspector-protocol.h b/android/x86/include/v8/v8-inspector-protocol.h
new file mode 100644
index 00000000..612a2ebc
--- /dev/null
+++ b/android/x86/include/v8/v8-inspector-protocol.h
@@ -0,0 +1,13 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_PROTOCOL_H_
+#define V8_V8_INSPECTOR_PROTOCOL_H_
+
+#include "inspector/Debugger.h"  // NOLINT(build/include)
+#include "inspector/Runtime.h"   // NOLINT(build/include)
+#include "inspector/Schema.h"    // NOLINT(build/include)
+#include "v8-inspector.h"        // NOLINT(build/include)
+
+#endif  // V8_V8_INSPECTOR_PROTOCOL_H_
diff --git a/android/x86/include/v8/v8-inspector.h b/android/x86/include/v8/v8-inspector.h
new file mode 100644
index 00000000..43bf3b4f
--- /dev/null
+++ b/android/x86/include/v8/v8-inspector.h
@@ -0,0 +1,267 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_INSPECTOR_H_
+#define V8_V8_INSPECTOR_H_
+
+#include <stdint.h>
+#include <cctype>
+
+#include <memory>
+
+#include "v8.h"  // NOLINT(build/include)
+
+namespace v8_inspector {
+
+namespace protocol {
+namespace Debugger {
+namespace API {
+class SearchMatch;
+}
+}
+namespace Runtime {
+namespace API {
+class RemoteObject;
+class StackTrace;
+}
+}
+namespace Schema {
+namespace API {
+class Domain;
+}
+}
+}  // namespace protocol
+
+class V8_EXPORT StringView {
+ public:
+  StringView() : m_is8Bit(true), m_length(0), m_characters8(nullptr) {}
+
+  StringView(const uint8_t* characters, size_t length)
+      : m_is8Bit(true), m_length(length), m_characters8(characters) {}
+
+  StringView(const uint16_t* characters, size_t length)
+      : m_is8Bit(false), m_length(length), m_characters16(characters) {}
+
+  bool is8Bit() const { return m_is8Bit; }
+  size_t length() const { return m_length; }
+
+  // TODO(dgozman): add DCHECK(m_is8Bit) to accessors once platform can be used
+  // here.
+  const uint8_t* characters8() const { return m_characters8; }
+  const uint16_t* characters16() const { return m_characters16; }
+
+ private:
+  bool m_is8Bit;
+  size_t m_length;
+  union {
+    const uint8_t* m_characters8;
+    const uint16_t* m_characters16;
+  };
+};
+
+class V8_EXPORT StringBuffer {
+ public:
+  virtual ~StringBuffer() {}
+  virtual const StringView& string() = 0;
+  // This method copies contents.
+  static std::unique_ptr<StringBuffer> create(const StringView&);
+};
+
+class V8_EXPORT V8ContextInfo {
+ public:
+  V8ContextInfo(v8::Local<v8::Context> context, int contextGroupId,
+                const StringView& humanReadableName)
+      : context(context),
+        contextGroupId(contextGroupId),
+        humanReadableName(humanReadableName),
+        hasMemoryOnConsole(false) {}
+
+  v8::Local<v8::Context> context;
+  // Each v8::Context is a part of a group. The group id must be non-zero.
+  int contextGroupId;
+  StringView humanReadableName;
+  StringView origin;
+  StringView auxData;
+  bool hasMemoryOnConsole;
+
+  static int executionContextId(v8::Local<v8::Context> context);
+
+ private:
+  // Disallow copying and allocating this one.
+  enum NotNullTagEnum { NotNullLiteral };
+  void* operator new(size_t) = delete;
+  void* operator new(size_t, NotNullTagEnum, void*) = delete;
+  void* operator new(size_t, void*) = delete;
+  V8ContextInfo(const V8ContextInfo&) = delete;
+  V8ContextInfo& operator=(const V8ContextInfo&) = delete;
+};
+
+class V8_EXPORT V8StackTrace {
+ public:
+  virtual bool isEmpty() const = 0;
+  virtual StringView topSourceURL() const = 0;
+  virtual int topLineNumber() const = 0;
+  virtual int topColumnNumber() const = 0;
+  virtual StringView topScriptId() const = 0;
+  virtual StringView topFunctionName() const = 0;
+
+  virtual ~V8StackTrace() {}
+  virtual std::unique_ptr<protocol::Runtime::API::StackTrace>
+  buildInspectorObject() const = 0;
+  virtual std::unique_ptr<StringBuffer> toString() const = 0;
+
+  // Safe to pass between threads, drops async chain.
+  virtual std::unique_ptr<V8StackTrace> clone() = 0;
+};
+
+class V8_EXPORT V8InspectorSession {
+ public:
+  virtual ~V8InspectorSession() {}
+
+  // Cross-context inspectable values (DOM nodes in different worlds, etc.).
+  class V8_EXPORT Inspectable {
+   public:
+    virtual v8::Local<v8::Value> get(v8::Local<v8::Context>) = 0;
+    virtual ~Inspectable() {}
+  };
+  virtual void addInspectedObject(std::unique_ptr<Inspectable>) = 0;
+
+  // Dispatching protocol messages.
+  static bool canDispatchMethod(const StringView& method);
+  virtual void dispatchProtocolMessage(const StringView& message) = 0;
+  virtual std::unique_ptr<StringBuffer> stateJSON() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Schema::API::Domain>>
+  supportedDomains() = 0;
+
+  // Debugger actions.
+  virtual void schedulePauseOnNextStatement(const StringView& breakReason,
+                                            const StringView& breakDetails) = 0;
+  virtual void cancelPauseOnNextStatement() = 0;
+  virtual void breakProgram(const StringView& breakReason,
+                            const StringView& breakDetails) = 0;
+  virtual void setSkipAllPauses(bool) = 0;
+  virtual void resume() = 0;
+  virtual void stepOver() = 0;
+  virtual std::vector<std::unique_ptr<protocol::Debugger::API::SearchMatch>>
+  searchInTextByLines(const StringView& text, const StringView& query,
+                      bool caseSensitive, bool isRegex) = 0;
+
+  // Remote objects.
+  virtual std::unique_ptr<protocol::Runtime::API::RemoteObject> wrapObject(
+      v8::Local<v8::Context>, v8::Local<v8::Value>,
+      const StringView& groupName) = 0;
+  virtual bool unwrapObject(std::unique_ptr<StringBuffer>* error,
+                            const StringView& objectId, v8::Local<v8::Value>*,
+                            v8::Local<v8::Context>*,
+                            std::unique_ptr<StringBuffer>* objectGroup) = 0;
+  virtual void releaseObjectGroup(const StringView&) = 0;
+};
+
+class V8_EXPORT V8InspectorClient {
+ public:
+  virtual ~V8InspectorClient() {}
+
+  virtual void runMessageLoopOnPause(int contextGroupId) {}
+  virtual void quitMessageLoopOnPause() {}
+  virtual void runIfWaitingForDebugger(int contextGroupId) {}
+
+  virtual void muteMetrics(int contextGroupId) {}
+  virtual void unmuteMetrics(int contextGroupId) {}
+
+  virtual void beginUserGesture() {}
+  virtual void endUserGesture() {}
+
+  virtual std::unique_ptr<StringBuffer> valueSubtype(v8::Local<v8::Value>) {
+    return nullptr;
+  }
+  virtual bool formatAccessorsAsProperties(v8::Local<v8::Value>) {
+    return false;
+  }
+  virtual bool isInspectableHeapObject(v8::Local<v8::Object>) { return true; }
+
+  virtual v8::Local<v8::Context> ensureDefaultContextInGroup(
+      int contextGroupId) {
+    return v8::Local<v8::Context>();
+  }
+  virtual void beginEnsureAllContextsInGroup(int contextGroupId) {}
+  virtual void endEnsureAllContextsInGroup(int contextGroupId) {}
+
+  virtual void installAdditionalCommandLineAPI(v8::Local<v8::Context>,
+                                               v8::Local<v8::Object>) {}
+  virtual void consoleAPIMessage(int contextGroupId,
+                                 v8::Isolate::MessageErrorLevel level,
+                                 const StringView& message,
+                                 const StringView& url, unsigned lineNumber,
+                                 unsigned columnNumber, V8StackTrace*) {}
+  virtual v8::MaybeLocal<v8::Value> memoryInfo(v8::Isolate*,
+                                               v8::Local<v8::Context>) {
+    return v8::MaybeLocal<v8::Value>();
+  }
+
+  virtual void consoleTime(const StringView& title) {}
+  virtual void consoleTimeEnd(const StringView& title) {}
+  virtual void consoleTimeStamp(const StringView& title) {}
+  virtual void consoleClear(int contextGroupId) {}
+  virtual double currentTimeMS() { return 0; }
+  typedef void (*TimerCallback)(void*);
+  virtual void startRepeatingTimer(double, TimerCallback, void* data) {}
+  virtual void cancelTimer(void* data) {}
+
+  // TODO(dgozman): this was added to support service worker shadow page. We
+  // should not connect at all.
+  virtual bool canExecuteScripts(int contextGroupId) { return true; }
+};
+
+class V8_EXPORT V8Inspector {
+ public:
+  static std::unique_ptr<V8Inspector> create(v8::Isolate*, V8InspectorClient*);
+  virtual ~V8Inspector() {}
+
+  // Contexts instrumentation.
+  virtual void contextCreated(const V8ContextInfo&) = 0;
+  virtual void contextDestroyed(v8::Local<v8::Context>) = 0;
+  virtual void resetContextGroup(int contextGroupId) = 0;
+
+  // Various instrumentation.
+  virtual void idleStarted() = 0;
+  virtual void idleFinished() = 0;
+
+  // Async stack traces instrumentation.
+  virtual void asyncTaskScheduled(const StringView& taskName, void* task,
+                                  bool recurring) = 0;
+  virtual void asyncTaskCanceled(void* task) = 0;
+  virtual void asyncTaskStarted(void* task) = 0;
+  virtual void asyncTaskFinished(void* task) = 0;
+  virtual void allAsyncTasksCanceled() = 0;
+
+  // Exceptions instrumentation.
+  virtual unsigned exceptionThrown(
+      v8::Local<v8::Context>, const StringView& message,
+      v8::Local<v8::Value> exception, const StringView& detailedMessage,
+      const StringView& url, unsigned lineNumber, unsigned columnNumber,
+      std::unique_ptr<V8StackTrace>, int scriptId) = 0;
+  virtual void exceptionRevoked(v8::Local<v8::Context>, unsigned exceptionId,
+                                const StringView& message) = 0;
+
+  // Connection.
+  class V8_EXPORT Channel {
+   public:
+    virtual ~Channel() {}
+    virtual void sendResponse(int callId,
+                              std::unique_ptr<StringBuffer> message) = 0;
+    virtual void sendNotification(std::unique_ptr<StringBuffer> message) = 0;
+    virtual void flushProtocolNotifications() = 0;
+  };
+  virtual std::unique_ptr<V8InspectorSession> connect(
+      int contextGroupId, Channel*, const StringView& state) = 0;
+
+  // API methods.
+  virtual std::unique_ptr<V8StackTrace> createStackTrace(
+      v8::Local<v8::StackTrace>) = 0;
+  virtual std::unique_ptr<V8StackTrace> captureStackTrace(bool fullStack) = 0;
+};
+
+}  // namespace v8_inspector
+
+#endif  // V8_V8_INSPECTOR_H_
diff --git a/android/x86/include/v8/v8-platform.h b/android/x86/include/v8/v8-platform.h
new file mode 100644
index 00000000..8f6d8042
--- /dev/null
+++ b/android/x86/include/v8/v8-platform.h
@@ -0,0 +1,227 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PLATFORM_H_
+#define V8_V8_PLATFORM_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <memory>
+#include <string>
+
+namespace v8 {
+
+class Isolate;
+
+/**
+ * A Task represents a unit of work.
+ */
+class Task {
+ public:
+  virtual ~Task() = default;
+
+  virtual void Run() = 0;
+};
+
+/**
+ * An IdleTask represents a unit of work to be performed in idle time.
+ * The Run method is invoked with an argument that specifies the deadline in
+ * seconds returned by MonotonicallyIncreasingTime().
+ * The idle task is expected to complete by this deadline.
+ */
+class IdleTask {
+ public:
+  virtual ~IdleTask() = default;
+  virtual void Run(double deadline_in_seconds) = 0;
+};
+
+/**
+ * The interface represents complex arguments to trace events.
+ */
+class ConvertableToTraceFormat {
+ public:
+  virtual ~ConvertableToTraceFormat() = default;
+
+  /**
+   * Append the class info to the provided |out| string. The appended
+   * data must be a valid JSON object. Strings must be properly quoted, and
+   * escaped. There is no processing applied to the content after it is
+   * appended.
+   */
+  virtual void AppendAsTraceFormat(std::string* out) const = 0;
+};
+
+/**
+ * V8 Platform abstraction layer.
+ *
+ * The embedder has to provide an implementation of this interface before
+ * initializing the rest of V8.
+ */
+class Platform {
+ public:
+  /**
+   * This enum is used to indicate whether a task is potentially long running,
+   * or causes a long wait. The embedder might want to use this hint to decide
+   * whether to execute the task on a dedicated thread.
+   */
+  enum ExpectedRuntime {
+    kShortRunningTask,
+    kLongRunningTask
+  };
+
+  virtual ~Platform() = default;
+
+  /**
+   * Gets the number of threads that are used to execute background tasks. Is
+   * used to estimate the number of tasks a work package should be split into.
+   * A return value of 0 means that there are no background threads available.
+   * Note that a value of 0 won't prohibit V8 from posting tasks using
+   * |CallOnBackgroundThread|.
+   */
+  virtual size_t NumberOfAvailableBackgroundThreads() { return 0; }
+
+  /**
+   * Schedules a task to be invoked on a background thread. |expected_runtime|
+   * indicates that the task will run a long time. The Platform implementation
+   * takes ownership of |task|. There is no guarantee about order of execution
+   * of tasks wrt order of scheduling, nor is there a guarantee about the
+   * thread the task will be run on.
+   */
+  virtual void CallOnBackgroundThread(Task* task,
+                                      ExpectedRuntime expected_runtime) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate|. Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallOnForegroundThread(Isolate* isolate, Task* task) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| after the given number of seconds |delay_in_seconds|.
+   * Tasks posted for the same isolate should be execute in order of
+   * scheduling. The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallDelayedOnForegroundThread(Isolate* isolate, Task* task,
+                                             double delay_in_seconds) = 0;
+
+  /**
+   * Schedules a task to be invoked on a foreground thread wrt a specific
+   * |isolate| when the embedder is idle.
+   * Requires that SupportsIdleTasks(isolate) is true.
+   * Idle tasks may be reordered relative to other task types and may be
+   * starved for an arbitrarily long time if no idle time is available.
+   * The definition of "foreground" is opaque to V8.
+   */
+  virtual void CallIdleOnForegroundThread(Isolate* isolate, IdleTask* task) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+  }
+
+  /**
+   * Returns true if idle tasks are enabled for the given |isolate|.
+   */
+  virtual bool IdleTasksEnabled(Isolate* isolate) {
+    // TODO(ulan): Make this function abstract after V8 roll in Chromium.
+    return false;
+  }
+
+  /**
+   * Monotonically increasing time in seconds from an arbitrary fixed point in
+   * the past. This function is expected to return at least
+   * millisecond-precision values. For this reason,
+   * it is recommended that the fixed point be no further in the past than
+   * the epoch.
+   **/
+  virtual double MonotonicallyIncreasingTime() = 0;
+
+  /**
+   * Called by TRACE_EVENT* macros, don't call this directly.
+   * The name parameter is a category group for example:
+   * TRACE_EVENT0("v8,parse", "V8.Parse")
+   * The pointer returned points to a value with zero or more of the bits
+   * defined in CategoryGroupEnabledFlags.
+   **/
+  virtual const uint8_t* GetCategoryGroupEnabled(const char* name) {
+    static uint8_t no = 0;
+    return &no;
+  }
+
+  /**
+   * Gets the category group name of the given category_enabled_flag pointer.
+   * Usually used while serliazing TRACE_EVENTs.
+   **/
+  virtual const char* GetCategoryGroupName(
+      const uint8_t* category_enabled_flag) {
+    static const char dummy[] = "dummy";
+    return dummy;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values, unsigned int flags) {
+    return 0;
+  }
+
+  /**
+   * Adds a trace event to the platform tracing system. This function call is
+   * usually the result of a TRACE_* macro from trace_event_common.h when
+   * tracing and the category of the particular trace are enabled. It is not
+   * advisable to call this function on its own; it is really only meant to be
+   * used by the trace macros. The returned handle can be used by
+   * UpdateTraceEventDuration to update the duration of COMPLETE events.
+   */
+  virtual uint64_t AddTraceEvent(
+      char phase, const uint8_t* category_enabled_flag, const char* name,
+      const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+      const char** arg_names, const uint8_t* arg_types,
+      const uint64_t* arg_values,
+      std::unique_ptr<ConvertableToTraceFormat>* arg_convertables,
+      unsigned int flags) {
+    return AddTraceEvent(phase, category_enabled_flag, name, scope, id, bind_id,
+                         num_args, arg_names, arg_types, arg_values, flags);
+  }
+
+  /**
+   * Sets the duration field of a COMPLETE trace event. It must be called with
+   * the handle returned from AddTraceEvent().
+   **/
+  virtual void UpdateTraceEventDuration(const uint8_t* category_enabled_flag,
+                                        const char* name, uint64_t handle) {}
+
+  class TraceStateObserver {
+   public:
+    virtual ~TraceStateObserver() = default;
+    virtual void OnTraceEnabled() = 0;
+    virtual void OnTraceDisabled() = 0;
+  };
+
+  /** Adds tracing state change observer. */
+  virtual void AddTraceStateObserver(TraceStateObserver*) {}
+
+  /** Removes tracing state change observer. */
+  virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
+
+  typedef void (*StackTracePrinter)();
+
+  /**
+   * Returns a function pointer that print a stack trace of the current stack
+   * on invocation. Disables printing of the stack trace if nullptr.
+   */
+  virtual StackTracePrinter GetStackTracePrinter() { return nullptr; }
+};
+
+}  // namespace v8
+
+#endif  // V8_V8_PLATFORM_H_
diff --git a/android/x86/include/v8/v8-profiler.h b/android/x86/include/v8/v8-profiler.h
new file mode 100644
index 00000000..b60d137f
--- /dev/null
+++ b/android/x86/include/v8/v8-profiler.h
@@ -0,0 +1,912 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_PROFILER_H_
+#define V8_V8_PROFILER_H_
+
+#include <unordered_set>
+#include <vector>
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Profiler support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class HeapGraphNode;
+struct HeapStatsUpdate;
+
+typedef uint32_t SnapshotObjectId;
+
+
+struct CpuProfileDeoptFrame {
+  int script_id;
+  size_t position;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptFrame>;
+#endif
+
+namespace v8 {
+
+struct V8_EXPORT CpuProfileDeoptInfo {
+  /** A pointer to a static string owned by v8. */
+  const char* deopt_reason;
+  std::vector<CpuProfileDeoptFrame> stack;
+};
+
+}  // namespace v8
+
+#ifdef V8_OS_WIN
+template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>;
+#endif
+
+namespace v8 {
+
+/**
+ * TracingCpuProfiler monitors tracing being enabled/disabled
+ * and emits CpuProfile trace events once v8.cpu_profiler tracing category
+ * is enabled. It has no overhead unless the category is enabled.
+ */
+class V8_EXPORT TracingCpuProfiler {
+ public:
+  static std::unique_ptr<TracingCpuProfiler> Create(Isolate*);
+  virtual ~TracingCpuProfiler() = default;
+
+ protected:
+  TracingCpuProfiler() = default;
+};
+
+// TickSample captures the information collected for each sample.
+struct TickSample {
+  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
+  // include the runtime function we're calling. Externally exposed tick
+  // samples don't care.
+  enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame };
+
+  TickSample()
+      : state(OTHER),
+        pc(nullptr),
+        external_callback_entry(nullptr),
+        frames_count(0),
+        has_external_callback(false),
+        update_stats(true) {}
+
+  /**
+   * Initialize a tick sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Execution state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param update_stats Whether update the sample to the aggregated stats.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   */
+  void Init(Isolate* isolate, const v8::RegisterState& state,
+            RecordCEntryFrame record_c_entry_frame, bool update_stats,
+            bool use_simulator_reg_state = true);
+  /**
+   * Get a call stack sample from the isolate.
+   * \param isolate The isolate.
+   * \param state Register state.
+   * \param record_c_entry_frame Include or skip the runtime function.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \param use_simulator_reg_state When set to true and V8 is running under a
+   *                                simulator, the method will use the simulator
+   *                                register state rather than the one provided
+   *                                with |state| argument. Otherwise the method
+   *                                will use provided register |state| as is.
+   * \note GetStackSample is thread and signal safe and should only be called
+   *                      when the JS thread is paused or interrupted.
+   *                      Otherwise the behavior is undefined.
+   */
+  static bool GetStackSample(Isolate* isolate, v8::RegisterState* state,
+                             RecordCEntryFrame record_c_entry_frame,
+                             void** frames, size_t frames_limit,
+                             v8::SampleInfo* sample_info,
+                             bool use_simulator_reg_state = true);
+  StateTag state;  // The state of the VM.
+  void* pc;        // Instruction pointer.
+  union {
+    void* tos;  // Top stack value (*sp).
+    void* external_callback_entry;
+  };
+  static const unsigned kMaxFramesCountLog2 = 8;
+  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
+  void* stack[kMaxFramesCount];                 // Call stack.
+  unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
+  bool has_external_callback : 1;
+  bool update_stats : 1;  // Whether the sample should update aggregated stats.
+};
+
+/**
+ * CpuProfileNode represents a node in a call graph.
+ */
+class V8_EXPORT CpuProfileNode {
+ public:
+  struct LineTick {
+    /** The 1-based number of the source line where the function originates. */
+    int line;
+
+    /** The count of samples associated with the source line. */
+    unsigned int hit_count;
+  };
+
+  /** Returns function name (empty string for anonymous functions.) */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns function name (empty string for anonymous functions.)
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetFunctionNameStr() const;
+
+  /** Returns id of the script where function is located. */
+  int GetScriptId() const;
+
+  /** Returns resource name for script from where the function originates. */
+  Local<String> GetScriptResourceName() const;
+
+  /**
+   * Returns resource name for script from where the function originates.
+   * The string ownership is *not* passed to the caller. It stays valid until
+   * profile is deleted. The function is thread safe.
+   */
+  const char* GetScriptResourceNameStr() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the function originates.
+   * kNoLineNumberInfo if no line number information is available.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns 1-based number of the column where the function originates.
+   * kNoColumnNumberInfo if no column number information is available.
+   */
+  int GetColumnNumber() const;
+
+  /**
+   * Returns the number of the function's source lines that collect the samples.
+   */
+  unsigned int GetHitLineCount() const;
+
+  /** Returns the set of source lines that collect the samples.
+   *  The caller allocates buffer and responsible for releasing it.
+   *  True if all available entries are copied, otherwise false.
+   *  The function copies nothing if buffer is not large enough.
+   */
+  bool GetLineTicks(LineTick* entries, unsigned int length) const;
+
+  /** Returns bailout reason for the function
+    * if the optimization was disabled for it.
+    */
+  const char* GetBailoutReason() const;
+
+  /**
+    * Returns the count of samples where the function was currently executing.
+    */
+  unsigned GetHitCount() const;
+
+  /** Returns function entry UID. */
+  V8_DEPRECATE_SOON(
+      "Use GetScriptId, GetLineNumber, and GetColumnNumber instead.",
+      unsigned GetCallUid() const);
+
+  /** Returns id of the node. The id is unique within the tree */
+  unsigned GetNodeId() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child node by index. */
+  const CpuProfileNode* GetChild(int index) const;
+
+  /** Retrieves deopt infos for the node. */
+  const std::vector<CpuProfileDeoptInfo>& GetDeoptInfos() const;
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * CpuProfile contains a CPU profile in a form of top-down call tree
+ * (from main() down to functions that do all the work).
+ */
+class V8_EXPORT CpuProfile {
+ public:
+  /** Returns CPU profile title. */
+  Local<String> GetTitle() const;
+
+  /** Returns the root node of the top down call tree. */
+  const CpuProfileNode* GetTopDownRoot() const;
+
+  /**
+   * Returns number of samples recorded. The samples are not recorded unless
+   * |record_samples| parameter of CpuProfiler::StartCpuProfiling is true.
+   */
+  int GetSamplesCount() const;
+
+  /**
+   * Returns profile node corresponding to the top frame the sample at
+   * the given index.
+   */
+  const CpuProfileNode* GetSample(int index) const;
+
+  /**
+   * Returns the timestamp of the sample. The timestamp is the number of
+   * microseconds since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetSampleTimestamp(int index) const;
+
+  /**
+   * Returns time when the profile recording was started (in microseconds)
+   * since some unspecified starting point.
+   */
+  int64_t GetStartTime() const;
+
+  /**
+   * Returns time when the profile recording was stopped (in microseconds)
+   * since some unspecified starting point.
+   * The point is equal to the starting point used by GetStartTime.
+   */
+  int64_t GetEndTime() const;
+
+  /**
+   * Deletes the profile and removes it from CpuProfiler's list.
+   * All pointers to nodes previously returned become invalid.
+   */
+  void Delete();
+};
+
+/**
+ * Interface for controlling CPU profiling. Instance of the
+ * profiler can be created using v8::CpuProfiler::New method.
+ */
+class V8_EXPORT CpuProfiler {
+ public:
+  /**
+   * Creates a new CPU profiler for the |isolate|. The isolate must be
+   * initialized. The profiler object must be disposed after use by calling
+   * |Dispose| method.
+   */
+  static CpuProfiler* New(Isolate* isolate);
+
+  /**
+   * Disposes the CPU profiler object.
+   */
+  void Dispose();
+
+  /**
+   * Changes default CPU profiler sampling interval to the specified number
+   * of microseconds. Default interval is 1000us. This method must be called
+   * when there are no profiles being recorded.
+   */
+  void SetSamplingInterval(int us);
+
+  /**
+   * Starts collecting CPU profile. Title may be an empty string. It
+   * is allowed to have several profiles being collected at
+   * once. Attempts to start collecting several profiles with the same
+   * title are silently ignored. While collecting a profile, functions
+   * from all security contexts are included in it. The token-based
+   * filtering is only performed when querying for a profile.
+   *
+   * |record_samples| parameter controls whether individual samples should
+   * be recorded in addition to the aggregated tree.
+   */
+  void StartProfiling(Local<String> title, bool record_samples = false);
+
+  /**
+   * Stops collecting CPU profile with a given title and returns it.
+   * If the title given is empty, finishes the last profile started.
+   */
+  CpuProfile* StopProfiling(Local<String> title);
+
+  /**
+   * Force collection of a sample. Must be called on the VM thread.
+   * Recording the forced sample does not contribute to the aggregated
+   * profile statistics.
+   */
+  void CollectSample();
+
+  /**
+   * Tells the profiler whether the embedder is idle.
+   */
+  void SetIdle(bool is_idle);
+
+ private:
+  CpuProfiler();
+  ~CpuProfiler();
+  CpuProfiler(const CpuProfiler&);
+  CpuProfiler& operator=(const CpuProfiler&);
+};
+
+
+/**
+ * HeapSnapshotEdge represents a directed connection between heap
+ * graph nodes: from retainers to retained nodes.
+ */
+class V8_EXPORT HeapGraphEdge {
+ public:
+  enum Type {
+    kContextVariable = 0,  // A variable from a function context.
+    kElement = 1,          // An element of an array.
+    kProperty = 2,         // A named object property.
+    kInternal = 3,         // A link that can't be accessed from JS,
+                           // thus, its name isn't a real property name
+                           // (e.g. parts of a ConsString).
+    kHidden = 4,           // A link that is needed for proper sizes
+                           // calculation, but may be hidden from user.
+    kShortcut = 5,         // A link that must not be followed during
+                           // sizes calculation.
+    kWeak = 6              // A weak reference (ignored by the GC).
+  };
+
+  /** Returns edge type (see HeapGraphEdge::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns edge name. This can be a variable name, an element index, or
+   * a property name.
+   */
+  Local<Value> GetName() const;
+
+  /** Returns origin node. */
+  const HeapGraphNode* GetFromNode() const;
+
+  /** Returns destination node. */
+  const HeapGraphNode* GetToNode() const;
+};
+
+
+/**
+ * HeapGraphNode represents a node in a heap graph.
+ */
+class V8_EXPORT HeapGraphNode {
+ public:
+  enum Type {
+    kHidden = 0,         // Hidden node, may be filtered when shown to user.
+    kArray = 1,          // An array of elements.
+    kString = 2,         // A string.
+    kObject = 3,         // A JS object (except for arrays and strings).
+    kCode = 4,           // Compiled code.
+    kClosure = 5,        // Function closure.
+    kRegExp = 6,         // RegExp.
+    kHeapNumber = 7,     // Number stored in the heap.
+    kNative = 8,         // Native object (not from V8 heap).
+    kSynthetic = 9,      // Synthetic object, usualy used for grouping
+                         // snapshot items together.
+    kConsString = 10,    // Concatenated string. A pair of pointers to strings.
+    kSlicedString = 11,  // Sliced string. A fragment of another string.
+    kSymbol = 12         // A Symbol (ES6).
+  };
+
+  /** Returns node type (see HeapGraphNode::Type). */
+  Type GetType() const;
+
+  /**
+   * Returns node name. Depending on node's type this can be the name
+   * of the constructor (for objects), the name of the function (for
+   * closures), string value, or an empty string (for compiled code).
+   */
+  Local<String> GetName() const;
+
+  /**
+   * Returns node id. For the same heap object, the id remains the same
+   * across all snapshots.
+   */
+  SnapshotObjectId GetId() const;
+
+  /** Returns node's own size, in bytes. */
+  size_t GetShallowSize() const;
+
+  /** Returns child nodes count of the node. */
+  int GetChildrenCount() const;
+
+  /** Retrieves a child by index. */
+  const HeapGraphEdge* GetChild(int index) const;
+};
+
+
+/**
+ * An interface for exporting data from V8, using "push" model.
+ */
+class V8_EXPORT OutputStream {  // NOLINT
+ public:
+  enum WriteResult {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~OutputStream() {}
+  /** Notify about the end of stream. */
+  virtual void EndOfStream() = 0;
+  /** Get preferred output chunk size. Called only once. */
+  virtual int GetChunkSize() { return 1024; }
+  /**
+   * Writes the next chunk of snapshot data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteAsciiChunk(char* data, int size) = 0;
+  /**
+   * Writes the next chunk of heap stats data into the stream. Writing
+   * can be stopped by returning kAbort as function result. EndOfStream
+   * will not be called in case writing was aborted.
+   */
+  virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate* data, int count) {
+    return kAbort;
+  }
+};
+
+
+/**
+ * HeapSnapshots record the state of the JS heap at some moment.
+ */
+class V8_EXPORT HeapSnapshot {
+ public:
+  enum SerializationFormat {
+    kJSON = 0  // See format description near 'Serialize' method.
+  };
+
+  /** Returns the root node of the heap graph. */
+  const HeapGraphNode* GetRoot() const;
+
+  /** Returns a node by its id. */
+  const HeapGraphNode* GetNodeById(SnapshotObjectId id) const;
+
+  /** Returns total nodes count in the snapshot. */
+  int GetNodesCount() const;
+
+  /** Returns a node by index. */
+  const HeapGraphNode* GetNode(int index) const;
+
+  /** Returns a max seen JS object Id. */
+  SnapshotObjectId GetMaxSnapshotJSObjectId() const;
+
+  /**
+   * Deletes the snapshot and removes it from HeapProfiler's list.
+   * All pointers to nodes, edges and paths previously returned become
+   * invalid.
+   */
+  void Delete();
+
+  /**
+   * Prepare a serialized representation of the snapshot. The result
+   * is written into the stream provided in chunks of specified size.
+   * The total length of the serialized snapshot is unknown in
+   * advance, it can be roughly equal to JS heap size (that means,
+   * it can be really big - tens of megabytes).
+   *
+   * For the JSON format, heap contents are represented as an object
+   * with the following structure:
+   *
+   *  {
+   *    snapshot: {
+   *      title: "...",
+   *      uid: nnn,
+   *      meta: { meta-info },
+   *      node_count: nnn,
+   *      edge_count: nnn
+   *    },
+   *    nodes: [nodes array],
+   *    edges: [edges array],
+   *    strings: [strings array]
+   *  }
+   *
+   * Nodes reference strings, other nodes, and edges by their indexes
+   * in corresponding arrays.
+   */
+  void Serialize(OutputStream* stream,
+                 SerializationFormat format = kJSON) const;
+};
+
+
+/**
+ * An interface for reporting progress and controlling long-running
+ * activities.
+ */
+class V8_EXPORT ActivityControl {  // NOLINT
+ public:
+  enum ControlOption {
+    kContinue = 0,
+    kAbort = 1
+  };
+  virtual ~ActivityControl() {}
+  /**
+   * Notify about current progress. The activity can be stopped by
+   * returning kAbort as the callback result.
+   */
+  virtual ControlOption ReportProgressValue(int done, int total) = 0;
+};
+
+
+/**
+ * AllocationProfile is a sampled profile of allocations done by the program.
+ * This is structured as a call-graph.
+ */
+class V8_EXPORT AllocationProfile {
+ public:
+  struct Allocation {
+    /**
+     * Size of the sampled allocation object.
+     */
+    size_t size;
+
+    /**
+     * The number of objects of such size that were sampled.
+     */
+    unsigned int count;
+  };
+
+  /**
+   * Represents a node in the call-graph.
+   */
+  struct Node {
+    /**
+     * Name of the function. May be empty for anonymous functions or if the
+     * script corresponding to this function has been unloaded.
+     */
+    Local<String> name;
+
+    /**
+     * Name of the script containing the function. May be empty if the script
+     * name is not available, or if the script has been unloaded.
+     */
+    Local<String> script_name;
+
+    /**
+     * id of the script where the function is located. May be equal to
+     * v8::UnboundScript::kNoScriptId in cases where the script doesn't exist.
+     */
+    int script_id;
+
+    /**
+     * Start position of the function in the script.
+     */
+    int start_position;
+
+    /**
+     * 1-indexed line number where the function starts. May be
+     * kNoLineNumberInfo if no line number information is available.
+     */
+    int line_number;
+
+    /**
+     * 1-indexed column number where the function starts. May be
+     * kNoColumnNumberInfo if no line number information is available.
+     */
+    int column_number;
+
+    /**
+     * List of callees called from this node for which we have sampled
+     * allocations. The lifetime of the children is scoped to the containing
+     * AllocationProfile.
+     */
+    std::vector<Node*> children;
+
+    /**
+     * List of self allocations done by this node in the call-graph.
+     */
+    std::vector<Allocation> allocations;
+  };
+
+  /**
+   * Returns the root node of the call-graph. The root node corresponds to an
+   * empty JS call-stack. The lifetime of the returned Node* is scoped to the
+   * containing AllocationProfile.
+   */
+  virtual Node* GetRootNode() = 0;
+
+  virtual ~AllocationProfile() {}
+
+  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
+  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
+};
+
+
+/**
+ * Interface for controlling heap profiling. Instance of the
+ * profiler can be retrieved using v8::Isolate::GetHeapProfiler.
+ */
+class V8_EXPORT HeapProfiler {
+ public:
+  enum SamplingFlags {
+    kSamplingNoFlags = 0,
+    kSamplingForceGC = 1 << 0,
+  };
+
+  typedef std::unordered_set<const v8::PersistentBase<v8::Value>*>
+      RetainerChildren;
+  typedef std::vector<std::pair<v8::RetainedObjectInfo*, RetainerChildren>>
+      RetainerGroups;
+  typedef std::vector<std::pair<const v8::PersistentBase<v8::Value>*,
+                                const v8::PersistentBase<v8::Value>*>>
+      RetainerEdges;
+
+  struct RetainerInfos {
+    RetainerGroups groups;
+    RetainerEdges edges;
+  };
+
+  /**
+   * Callback function invoked to retrieve all RetainerInfos from the embedder.
+   */
+  typedef RetainerInfos (*GetRetainerInfosCallback)(v8::Isolate* isolate);
+
+  /**
+   * Callback function invoked for obtaining RetainedObjectInfo for
+   * the given JavaScript wrapper object. It is prohibited to enter V8
+   * while the callback is running: only getters on the handle and
+   * GetPointerFromInternalField on the objects are allowed.
+   */
+  typedef RetainedObjectInfo* (*WrapperInfoCallback)(uint16_t class_id,
+                                                     Local<Value> wrapper);
+
+  /** Returns the number of snapshots taken. */
+  int GetSnapshotCount();
+
+  /** Returns a snapshot by index. */
+  const HeapSnapshot* GetHeapSnapshot(int index);
+
+  /**
+   * Returns SnapshotObjectId for a heap object referenced by |value| if
+   * it has been seen by the heap profiler, kUnknownObjectId otherwise.
+   */
+  SnapshotObjectId GetObjectId(Local<Value> value);
+
+  /**
+   * Returns heap object with given SnapshotObjectId if the object is alive,
+   * otherwise empty handle is returned.
+   */
+  Local<Value> FindObjectById(SnapshotObjectId id);
+
+  /**
+   * Clears internal map from SnapshotObjectId to heap object. The new objects
+   * will not be added into it unless a heap snapshot is taken or heap object
+   * tracking is kicked off.
+   */
+  void ClearObjectIds();
+
+  /**
+   * A constant for invalid SnapshotObjectId. GetSnapshotObjectId will return
+   * it in case heap profiler cannot find id  for the object passed as
+   * parameter. HeapSnapshot::GetNodeById will always return NULL for such id.
+   */
+  static const SnapshotObjectId kUnknownObjectId = 0;
+
+  /**
+   * Callback interface for retrieving user friendly names of global objects.
+   */
+  class ObjectNameResolver {
+   public:
+    /**
+     * Returns name to be used in the heap snapshot for given node. Returned
+     * string must stay alive until snapshot collection is completed.
+     */
+    virtual const char* GetName(Local<Object> object) = 0;
+
+   protected:
+    virtual ~ObjectNameResolver() {}
+  };
+
+  /**
+   * Takes a heap snapshot and returns it.
+   */
+  const HeapSnapshot* TakeHeapSnapshot(
+      ActivityControl* control = NULL,
+      ObjectNameResolver* global_object_name_resolver = NULL);
+
+  /**
+   * Starts tracking of heap objects population statistics. After calling
+   * this method, all heap objects relocations done by the garbage collector
+   * are being registered.
+   *
+   * |track_allocations| parameter controls whether stack trace of each
+   * allocation in the heap will be recorded and reported as part of
+   * HeapSnapshot.
+   */
+  void StartTrackingHeapObjects(bool track_allocations = false);
+
+  /**
+   * Adds a new time interval entry to the aggregated statistics array. The
+   * time interval entry contains information on the current heap objects
+   * population size. The method also updates aggregated statistics and
+   * reports updates for all previous time intervals via the OutputStream
+   * object. Updates on each time interval are provided as a stream of the
+   * HeapStatsUpdate structure instances.
+   * If |timestamp_us| is supplied, timestamp of the new entry will be written
+   * into it. The return value of the function is the last seen heap object Id.
+   *
+   * StartTrackingHeapObjects must be called before the first call to this
+   * method.
+   */
+  SnapshotObjectId GetHeapStats(OutputStream* stream,
+                                int64_t* timestamp_us = NULL);
+
+  /**
+   * Stops tracking of heap objects population statistics, cleans up all
+   * collected data. StartHeapObjectsTracking must be called again prior to
+   * calling GetHeapStats next time.
+   */
+  void StopTrackingHeapObjects();
+
+  /**
+   * Starts gathering a sampling heap profile. A sampling heap profile is
+   * similar to tcmalloc's heap profiler and Go's mprof. It samples object
+   * allocations and builds an online 'sampling' heap profile. At any point in
+   * time, this profile is expected to be a representative sample of objects
+   * currently live in the system. Each sampled allocation includes the stack
+   * trace at the time of allocation, which makes this really useful for memory
+   * leak detection.
+   *
+   * This mechanism is intended to be cheap enough that it can be used in
+   * production with minimal performance overhead.
+   *
+   * Allocations are sampled using a randomized Poisson process. On average, one
+   * allocation will be sampled every |sample_interval| bytes allocated. The
+   * |stack_depth| parameter controls the maximum number of stack frames to be
+   * captured on each allocation.
+   *
+   * NOTE: This is a proof-of-concept at this point. Right now we only sample
+   * newspace allocations. Support for paged space allocation (e.g. pre-tenured
+   * objects, large objects, code objects, etc.) and native allocations
+   * doesn't exist yet, but is anticipated in the future.
+   *
+   * Objects allocated before the sampling is started will not be included in
+   * the profile.
+   *
+   * Returns false if a sampling heap profiler is already running.
+   */
+  bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024,
+                                 int stack_depth = 16,
+                                 SamplingFlags flags = kSamplingNoFlags);
+
+  /**
+   * Stops the sampling heap profile and discards the current profile.
+   */
+  void StopSamplingHeapProfiler();
+
+  /**
+   * Returns the sampled profile of allocations allocated (and still live) since
+   * StartSamplingHeapProfiler was called. The ownership of the pointer is
+   * transfered to the caller. Returns nullptr if sampling heap profiler is not
+   * active.
+   */
+  AllocationProfile* GetAllocationProfile();
+
+  /**
+   * Deletes all snapshots taken. All previously returned pointers to
+   * snapshots and their contents become invalid after this call.
+   */
+  void DeleteAllHeapSnapshots();
+
+  /** Binds a callback to embedder's class ID. */
+  void SetWrapperClassInfoProvider(
+      uint16_t class_id,
+      WrapperInfoCallback callback);
+
+  void SetGetRetainerInfosCallback(GetRetainerInfosCallback callback);
+
+  /**
+   * Default value of persistent handle class ID. Must not be used to
+   * define a class. Can be used to reset a class of a persistent
+   * handle.
+   */
+  static const uint16_t kPersistentHandleNoClassId = 0;
+
+  /** Returns memory used for profiler internal data and snapshots. */
+  size_t GetProfilerMemorySize();
+
+ private:
+  HeapProfiler();
+  ~HeapProfiler();
+  HeapProfiler(const HeapProfiler&);
+  HeapProfiler& operator=(const HeapProfiler&);
+};
+
+/**
+ * Interface for providing information about embedder's objects
+ * held by global handles. This information is reported in two ways:
+ *
+ *  1. When calling AddObjectGroup, an embedder may pass
+ *     RetainedObjectInfo instance describing the group.  To collect
+ *     this information while taking a heap snapshot, V8 calls GC
+ *     prologue and epilogue callbacks.
+ *
+ *  2. When a heap snapshot is collected, V8 additionally
+ *     requests RetainedObjectInfos for persistent handles that
+ *     were not previously reported via AddObjectGroup.
+ *
+ * Thus, if an embedder wants to provide information about native
+ * objects for heap snapshots, it can do it in a GC prologue
+ * handler, and / or by assigning wrapper class ids in the following way:
+ *
+ *  1. Bind a callback to class id by calling SetWrapperClassInfoProvider.
+ *  2. Call SetWrapperClassId on certain persistent handles.
+ *
+ * V8 takes ownership of RetainedObjectInfo instances passed to it and
+ * keeps them alive only during snapshot collection. Afterwards, they
+ * are freed by calling the Dispose class function.
+ */
+class V8_EXPORT RetainedObjectInfo {  // NOLINT
+ public:
+  /** Called by V8 when it no longer needs an instance. */
+  virtual void Dispose() = 0;
+
+  /** Returns whether two instances are equivalent. */
+  virtual bool IsEquivalent(RetainedObjectInfo* other) = 0;
+
+  /**
+   * Returns hash value for the instance. Equivalent instances
+   * must have the same hash value.
+   */
+  virtual intptr_t GetHash() = 0;
+
+  /**
+   * Returns human-readable label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetLabel.
+   */
+  virtual const char* GetLabel() = 0;
+
+  /**
+   * Returns human-readable group label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetGroupLabel.
+   * Heap snapshot generator will collect all the group names, create
+   * top level entries with these names and attach the objects to the
+   * corresponding top level group objects. There is a default
+   * implementation which is required because embedders don't have their
+   * own implementation yet.
+   */
+  virtual const char* GetGroupLabel() { return GetLabel(); }
+
+  /**
+   * Returns element count in case if a global handle retains
+   * a subgraph by holding one of its nodes.
+   */
+  virtual intptr_t GetElementCount() { return -1; }
+
+  /** Returns embedder's object size in bytes. */
+  virtual intptr_t GetSizeInBytes() { return -1; }
+
+ protected:
+  RetainedObjectInfo() {}
+  virtual ~RetainedObjectInfo() {}
+
+ private:
+  RetainedObjectInfo(const RetainedObjectInfo&);
+  RetainedObjectInfo& operator=(const RetainedObjectInfo&);
+};
+
+
+/**
+ * A struct for exporting HeapStats data from V8, using "push" model.
+ * See HeapProfiler::GetHeapStats.
+ */
+struct HeapStatsUpdate {
+  HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size)
+    : index(index), count(count), size(size) { }
+  uint32_t index;  // Index of the time interval that was changed.
+  uint32_t count;  // New value of count field for the interval with this index.
+  uint32_t size;  // New value of size field for the interval with this index.
+};
+
+
+}  // namespace v8
+
+
+#endif  // V8_V8_PROFILER_H_
diff --git a/android/x86/include/v8/v8-testing.h b/android/x86/include/v8/v8-testing.h
new file mode 100644
index 00000000..f67bf253
--- /dev/null
+++ b/android/x86/include/v8/v8-testing.h
@@ -0,0 +1,48 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_V8_TEST_H_
+#define V8_V8_TEST_H_
+
+#include "v8.h"  // NOLINT(build/include)
+
+/**
+ * Testing support for the V8 JavaScript engine.
+ */
+namespace v8 {
+
+class V8_EXPORT Testing {
+ public:
+  enum StressType {
+    kStressTypeOpt,
+    kStressTypeDeopt
+  };
+
+  /**
+   * Set the type of stressing to do. The default if not set is kStressTypeOpt.
+   */
+  static void SetStressRunType(StressType type);
+
+  /**
+   * Get the number of runs of a given test that is required to get the full
+   * stress coverage.
+   */
+  static int GetStressRuns();
+
+  /**
+   * Indicate the number of the run which is about to start. The value of run
+   * should be between 0 and one less than the result from GetStressRuns()
+   */
+  static void PrepareStressRun(int run);
+
+  /**
+   * Force deoptimization of all functions.
+   */
+  static void DeoptimizeAll(Isolate* isolate);
+};
+
+
+}  // namespace v8
+
+#endif  // V8_V8_TEST_H_
diff --git a/android/x86/include/v8/v8-util.h b/android/x86/include/v8/v8-util.h
new file mode 100644
index 00000000..a04a5e84
--- /dev/null
+++ b/android/x86/include/v8/v8-util.h
@@ -0,0 +1,655 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_UTIL_H_
+#define V8_UTIL_H_
+
+#include "v8.h"  // NOLINT(build/include)
+#include <assert.h>
+#include <map>
+#include <vector>
+
+/**
+ * Support for Persistent containers.
+ *
+ * C++11 embedders can use STL containers with Global values,
+ * but pre-C++11 does not support the required move semantic and hence
+ * may want these container classes.
+ */
+namespace v8 {
+
+typedef uintptr_t PersistentContainerValue;
+static const uintptr_t kPersistentContainerNotFound = 0;
+enum PersistentContainerCallbackType {
+  kNotWeak,
+  // These correspond to v8::WeakCallbackType
+  kWeakWithParameter,
+  kWeakWithInternalFields,
+  kWeak = kWeakWithParameter  // For backwards compatibility.  Deprecate.
+};
+
+
+/**
+ * A default trait implemenation for PersistentValueMap which uses std::map
+ * as a backing map.
+ *
+ * Users will have to implement their own weak callbacks & dispose traits.
+ */
+template<typename K, typename V>
+class StdMapTraits {
+ public:
+  // STL map & related:
+  typedef std::map<K, PersistentContainerValue> Impl;
+  typedef typename Impl::iterator Iterator;
+
+  static bool Empty(Impl* impl) { return impl->empty(); }
+  static size_t Size(Impl* impl) { return impl->size(); }
+  static void Swap(Impl& a, Impl& b) { std::swap(a, b); }  // NOLINT
+  static Iterator Begin(Impl* impl) { return impl->begin(); }
+  static Iterator End(Impl* impl) { return impl->end(); }
+  static K Key(Iterator it) { return it->first; }
+  static PersistentContainerValue Value(Iterator it) { return it->second; }
+  static PersistentContainerValue Set(Impl* impl, K key,
+      PersistentContainerValue value) {
+    std::pair<Iterator, bool> res = impl->insert(std::make_pair(key, value));
+    PersistentContainerValue old_value = kPersistentContainerNotFound;
+    if (!res.second) {
+      old_value = res.first->second;
+      res.first->second = value;
+    }
+    return old_value;
+  }
+  static PersistentContainerValue Get(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    return it->second;
+  }
+  static PersistentContainerValue Remove(Impl* impl, K key) {
+    Iterator it = impl->find(key);
+    if (it == impl->end()) return kPersistentContainerNotFound;
+    PersistentContainerValue value = it->second;
+    impl->erase(it);
+    return value;
+  }
+};
+
+
+/**
+ * A default trait implementation for PersistentValueMap, which inherits
+ * a std:map backing map from StdMapTraits and holds non-weak persistent
+ * objects and has no special Dispose handling.
+ *
+ * You should not derive from this class, since MapType depends on the
+ * surrounding class, and hence a subclass cannot simply inherit the methods.
+ */
+template<typename K, typename V>
+class DefaultPersistentValueMapTraits : public StdMapTraits<K, V> {
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef PersistentValueMap<K, V, DefaultPersistentValueMapTraits<K, V> >
+      MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(
+      MapType* map, const K& key, Local<V> value) {
+    return NULL;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return NULL;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) { }
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+};
+
+
+template <typename K, typename V>
+class DefaultGlobalMapTraits : public StdMapTraits<K, V> {
+ private:
+  template <typename T>
+  struct RemovePointer;
+
+ public:
+  // Weak callback & friends:
+  static const PersistentContainerCallbackType kCallbackType = kNotWeak;
+  typedef GlobalValueMap<K, V, DefaultGlobalMapTraits<K, V> > MapType;
+  typedef void WeakCallbackDataType;
+
+  static WeakCallbackDataType* WeakCallbackParameter(MapType* map, const K& key,
+                                                     Local<V> value) {
+    return nullptr;
+  }
+  static MapType* MapFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return nullptr;
+  }
+  static K KeyFromWeakCallbackInfo(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {
+    return K();
+  }
+  static void DisposeCallbackData(WeakCallbackDataType* data) {}
+  static void OnWeakCallback(
+      const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+  static void Dispose(Isolate* isolate, Global<V> value, K key) {}
+  // This is a second pass callback, so SetSecondPassCallback cannot be called.
+  static void DisposeWeak(const WeakCallbackInfo<WeakCallbackDataType>& data) {}
+
+ private:
+  template <typename T>
+  struct RemovePointer<T*> {
+    typedef T Type;
+  };
+};
+
+
+/**
+ * A map wrapper that allows using Global as a mapped value.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * The map relies on a backing map, whose type and accessors are described
+ * by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template <typename K, typename V, typename Traits>
+class PersistentValueMapBase {
+ public:
+  Isolate* GetIsolate() { return isolate_; }
+
+  /**
+   * Return size of the map.
+   */
+  size_t Size() { return Traits::Size(&impl_); }
+
+  /**
+   * Return whether the map holds weak persistents.
+   */
+  bool IsWeak() { return Traits::kCallbackType != kNotWeak; }
+
+  /**
+   * Get value stored in map.
+   */
+  Local<V> Get(const K& key) {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, key)));
+  }
+
+  /**
+   * Check whether a value is contained in the map.
+   */
+  bool Contains(const K& key) {
+    return Traits::Get(&impl_, key) != kPersistentContainerNotFound;
+  }
+
+  /**
+   * Get value stored in map and set it in returnValue.
+   * Return true if a value was found.
+   */
+  bool SetReturnValue(const K& key,
+      ReturnValue<Value> returnValue) {
+    return SetReturnValueFromVal(&returnValue, Traits::Get(&impl_, key));
+  }
+
+  /**
+   * Call Isolate::SetReference with the given parent and the map value.
+   */
+  void SetReference(const K& key,
+      const Persistent<Object>& parent) {
+    GetIsolate()->SetReference(
+      reinterpret_cast<internal::Object**>(parent.val_),
+      reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))));
+  }
+
+  /**
+   * Call V8::RegisterExternallyReferencedObject with the map value for given
+   * key.
+   */
+  void RegisterExternallyReferencedObject(K& key) {
+    assert(Contains(key));
+    V8::RegisterExternallyReferencedObject(
+        reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))),
+        reinterpret_cast<internal::Isolate*>(GetIsolate()));
+  }
+
+  /**
+   * Return value for key and remove it from the map.
+   */
+  Global<V> Remove(const K& key) {
+    return Release(Traits::Remove(&impl_, key)).Pass();
+  }
+
+  /**
+  * Traverses the map repeatedly,
+  * in case side effects of disposal cause insertions.
+  **/
+  void Clear() {
+    typedef typename Traits::Iterator It;
+    HandleScope handle_scope(isolate_);
+    // TODO(dcarney): figure out if this swap and loop is necessary.
+    while (!Traits::Empty(&impl_)) {
+      typename Traits::Impl impl;
+      Traits::Swap(impl_, impl);
+      for (It i = Traits::Begin(&impl); i != Traits::End(&impl); ++i) {
+        Traits::Dispose(isolate_, Release(Traits::Value(i)).Pass(),
+                        Traits::Key(i));
+      }
+    }
+  }
+
+  /**
+   * Helper class for GetReference/SetWithReference. Do not use outside
+   * that context.
+   */
+  class PersistentValueReference {
+   public:
+    PersistentValueReference() : value_(kPersistentContainerNotFound) { }
+    PersistentValueReference(const PersistentValueReference& other)
+        : value_(other.value_) { }
+
+    Local<V> NewLocal(Isolate* isolate) const {
+      return Local<V>::New(isolate, FromVal(value_));
+    }
+    bool IsEmpty() const {
+      return value_ == kPersistentContainerNotFound;
+    }
+    template<typename T>
+    bool SetReturnValue(ReturnValue<T> returnValue) {
+      return SetReturnValueFromVal(&returnValue, value_);
+    }
+    void Reset() {
+      value_ = kPersistentContainerNotFound;
+    }
+    void operator=(const PersistentValueReference& other) {
+      value_ = other.value_;
+    }
+
+   private:
+    friend class PersistentValueMapBase;
+    friend class PersistentValueMap<K, V, Traits>;
+    friend class GlobalValueMap<K, V, Traits>;
+
+    explicit PersistentValueReference(PersistentContainerValue value)
+        : value_(value) { }
+
+    void operator=(PersistentContainerValue value) {
+      value_ = value;
+    }
+
+    PersistentContainerValue value_;
+  };
+
+  /**
+   * Get a reference to a map value. This enables fast, repeated access
+   * to a value stored in the map while the map remains unchanged.
+   *
+   * Careful: This is potentially unsafe, so please use with care.
+   * The value will become invalid if the value for this key changes
+   * in the underlying map, as a result of Set or Remove for the same
+   * key; as a result of the weak callback for the same key; or as a
+   * result of calling Clear() or destruction of the map.
+   */
+  PersistentValueReference GetReference(const K& key) {
+    return PersistentValueReference(Traits::Get(&impl_, key));
+  }
+
+ protected:
+  explicit PersistentValueMapBase(Isolate* isolate) : isolate_(isolate) {}
+
+  ~PersistentValueMapBase() { Clear(); }
+
+  Isolate* isolate() { return isolate_; }
+  typename Traits::Impl* impl() { return &impl_; }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static PersistentContainerValue Leak(Global<V>* persistent) {
+    return reinterpret_cast<PersistentContainerValue>(persistent->val_);
+  }
+
+  /**
+   * Return a container value as Global and make sure the weak
+   * callback is properly disposed of. All remove functionality should go
+   * through this.
+   */
+  static Global<V> Release(PersistentContainerValue v) {
+    Global<V> p;
+    p.val_ = FromVal(v);
+    if (Traits::kCallbackType != kNotWeak && p.IsWeak()) {
+      Traits::DisposeCallbackData(
+          p.template ClearWeak<typename Traits::WeakCallbackDataType>());
+    }
+    return p.Pass();
+  }
+
+  void RemoveWeak(const K& key) {
+    Global<V> p;
+    p.val_ = FromVal(Traits::Remove(&impl_, key));
+    p.Reset();
+  }
+
+ private:
+  PersistentValueMapBase(PersistentValueMapBase&);
+  void operator=(PersistentValueMapBase&);
+
+  static bool SetReturnValueFromVal(ReturnValue<Value>* returnValue,
+                                    PersistentContainerValue value) {
+    bool hasValue = value != kPersistentContainerNotFound;
+    if (hasValue) {
+      returnValue->SetInternal(
+          *reinterpret_cast<internal::Object**>(FromVal(value)));
+    }
+    return hasValue;
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+
+template <typename K, typename V, typename Traits>
+class PersistentValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit PersistentValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+        Traits::WeakCallbackParameter(this, key, value), WeakCallback);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void WeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      PersistentValueMap<K, V, Traits>* persistentValueMap =
+          Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      Traits::Dispose(data.GetIsolate(),
+                      persistentValueMap->Remove(key).Pass(), key);
+      Traits::DisposeCallbackData(data.GetParameter());
+    }
+  }
+};
+
+
+template <typename K, typename V, typename Traits>
+class GlobalValueMap : public PersistentValueMapBase<K, V, Traits> {
+ public:
+  explicit GlobalValueMap(Isolate* isolate)
+      : PersistentValueMapBase<K, V, Traits>(isolate) {}
+
+  typedef
+      typename PersistentValueMapBase<K, V, Traits>::PersistentValueReference
+          PersistentValueReference;
+
+  /**
+   * Put value into map. Depending on Traits::kIsWeak, the value will be held
+   * by the map strongly or weakly.
+   * Returns old value as Global.
+   */
+  Global<V> Set(const K& key, Local<V> value) {
+    Global<V> persistent(this->isolate(), value);
+    return SetUnique(key, &persistent);
+  }
+
+  /**
+   * Put value into map, like Set(const K&, Local<V>).
+   */
+  Global<V> Set(const K& key, Global<V> value) {
+    return SetUnique(key, &value);
+  }
+
+  /**
+   * Put the value into the map, and set the 'weak' callback when demanded
+   * by the Traits class.
+   */
+  Global<V> SetUnique(const K& key, Global<V>* persistent) {
+    if (Traits::kCallbackType != kNotWeak) {
+      WeakCallbackType callback_type =
+          Traits::kCallbackType == kWeakWithInternalFields
+              ? WeakCallbackType::kInternalFields
+              : WeakCallbackType::kParameter;
+      Local<V> value(Local<V>::New(this->isolate(), *persistent));
+      persistent->template SetWeak<typename Traits::WeakCallbackDataType>(
+          Traits::WeakCallbackParameter(this, key, value), OnWeakCallback,
+          callback_type);
+    }
+    PersistentContainerValue old_value =
+        Traits::Set(this->impl(), key, this->ClearAndLeak(persistent));
+    return this->Release(old_value).Pass();
+  }
+
+  /**
+   * Put a value into the map and update the reference.
+   * Restrictions of GetReference apply here as well.
+   */
+  Global<V> Set(const K& key, Global<V> value,
+                PersistentValueReference* reference) {
+    *reference = this->Leak(&value);
+    return SetUnique(key, &value);
+  }
+
+ private:
+  static void OnWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    if (Traits::kCallbackType != kNotWeak) {
+      auto map = Traits::MapFromWeakCallbackInfo(data);
+      K key = Traits::KeyFromWeakCallbackInfo(data);
+      map->RemoveWeak(key);
+      Traits::OnWeakCallback(data);
+      data.SetSecondPassCallback(SecondWeakCallback);
+    }
+  }
+
+  static void SecondWeakCallback(
+      const WeakCallbackInfo<typename Traits::WeakCallbackDataType>& data) {
+    Traits::DisposeWeak(data);
+  }
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Persistents are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template<typename K, typename V,
+    typename Traits = DefaultPersistentValueMapTraits<K, V> >
+class StdPersistentValueMap : public PersistentValueMap<K, V, Traits> {
+ public:
+  explicit StdPersistentValueMap(Isolate* isolate)
+      : PersistentValueMap<K, V, Traits>(isolate) {}
+};
+
+
+/**
+ * A map that uses Global as value and std::map as the backing
+ * implementation. Globals are held non-weak.
+ *
+ * C++11 embedders don't need this class, as they can use
+ * Global directly in std containers.
+ */
+template <typename K, typename V,
+          typename Traits = DefaultGlobalMapTraits<K, V> >
+class StdGlobalValueMap : public GlobalValueMap<K, V, Traits> {
+ public:
+  explicit StdGlobalValueMap(Isolate* isolate)
+      : GlobalValueMap<K, V, Traits>(isolate) {}
+};
+
+
+class DefaultPersistentValueVectorTraits {
+ public:
+  typedef std::vector<PersistentContainerValue> Impl;
+
+  static void Append(Impl* impl, PersistentContainerValue value) {
+    impl->push_back(value);
+  }
+  static bool IsEmpty(const Impl* impl) {
+    return impl->empty();
+  }
+  static size_t Size(const Impl* impl) {
+    return impl->size();
+  }
+  static PersistentContainerValue Get(const Impl* impl, size_t i) {
+    return (i < impl->size()) ? impl->at(i) : kPersistentContainerNotFound;
+  }
+  static void ReserveCapacity(Impl* impl, size_t capacity) {
+    impl->reserve(capacity);
+  }
+  static void Clear(Impl* impl) {
+    impl->clear();
+  }
+};
+
+
+/**
+ * A vector wrapper that safely stores Global values.
+ * C++11 embedders don't need this class, as they can use Global
+ * directly in std containers.
+ *
+ * This class relies on a backing vector implementation, whose type and methods
+ * are described by the Traits class. The backing map will handle values of type
+ * PersistentContainerValue, with all conversion into and out of V8
+ * handles being transparently handled by this class.
+ */
+template<typename V, typename Traits = DefaultPersistentValueVectorTraits>
+class PersistentValueVector {
+ public:
+  explicit PersistentValueVector(Isolate* isolate) : isolate_(isolate) { }
+
+  ~PersistentValueVector() {
+    Clear();
+  }
+
+  /**
+   * Append a value to the vector.
+   */
+  void Append(Local<V> value) {
+    Global<V> persistent(isolate_, value);
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Append a persistent's value to the vector.
+   */
+  void Append(Global<V> persistent) {
+    Traits::Append(&impl_, ClearAndLeak(&persistent));
+  }
+
+  /**
+   * Are there any values in the vector?
+   */
+  bool IsEmpty() const {
+    return Traits::IsEmpty(&impl_);
+  }
+
+  /**
+   * How many elements are in the vector?
+   */
+  size_t Size() const {
+    return Traits::Size(&impl_);
+  }
+
+  /**
+   * Retrieve the i-th value in the vector.
+   */
+  Local<V> Get(size_t index) const {
+    return Local<V>::New(isolate_, FromVal(Traits::Get(&impl_, index)));
+  }
+
+  /**
+   * Remove all elements from the vector.
+   */
+  void Clear() {
+    size_t length = Traits::Size(&impl_);
+    for (size_t i = 0; i < length; i++) {
+      Global<V> p;
+      p.val_ = FromVal(Traits::Get(&impl_, i));
+    }
+    Traits::Clear(&impl_);
+  }
+
+  /**
+   * Reserve capacity in the vector.
+   * (Efficiency gains depend on the backing implementation.)
+   */
+  void ReserveCapacity(size_t capacity) {
+    Traits::ReserveCapacity(&impl_, capacity);
+  }
+
+ private:
+  static PersistentContainerValue ClearAndLeak(Global<V>* persistent) {
+    V* v = persistent->val_;
+    persistent->val_ = 0;
+    return reinterpret_cast<PersistentContainerValue>(v);
+  }
+
+  static V* FromVal(PersistentContainerValue v) {
+    return reinterpret_cast<V*>(v);
+  }
+
+  Isolate* isolate_;
+  typename Traits::Impl impl_;
+};
+
+}  // namespace v8
+
+#endif  // V8_UTIL_H
diff --git a/android/x86/include/v8/v8-value-serializer-version.h b/android/x86/include/v8/v8-value-serializer-version.h
new file mode 100644
index 00000000..c72911c6
--- /dev/null
+++ b/android/x86/include/v8/v8-value-serializer-version.h
@@ -0,0 +1,24 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Compile-time constants.
+ *
+ * This header provides access to information about the value serializer at
+ * compile time, without declaring or defining any symbols that require linking
+ * to V8.
+ */
+
+#ifndef INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+#define INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
+
+#include <stdint.h>
+
+namespace v8 {
+
+constexpr uint32_t CurrentValueSerializerFormatVersion() { return 13; }
+
+}  // namespace v8
+
+#endif  // INCLUDE_V8_VALUE_SERIALIZER_VERSION_H_
diff --git a/android/x86/include/v8/v8-version-string.h b/android/x86/include/v8/v8-version-string.h
new file mode 100644
index 00000000..075282de
--- /dev/null
+++ b/android/x86/include/v8/v8-version-string.h
@@ -0,0 +1,33 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_VERSION_STRING_H_
+#define V8_VERSION_STRING_H_
+
+#include "v8-version.h"  // NOLINT(build/include)
+
+// This is here rather than v8-version.h to keep that file simple and
+// machine-processable.
+
+#if V8_IS_CANDIDATE_VERSION
+#define V8_CANDIDATE_STRING " (candidate)"
+#else
+#define V8_CANDIDATE_STRING ""
+#endif
+
+#define V8_SX(x) #x
+#define V8_S(x) V8_SX(x)
+
+#if V8_PATCH_LEVEL > 0
+#define V8_VERSION_STRING                                        \
+  V8_S(V8_MAJOR_VERSION)                                         \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) "." V8_S( \
+      V8_PATCH_LEVEL) V8_CANDIDATE_STRING
+#else
+#define V8_VERSION_STRING \
+  V8_S(V8_MAJOR_VERSION)  \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) V8_CANDIDATE_STRING
+#endif
+
+#endif  // V8_VERSION_STRING_H_
diff --git a/android/x86/include/v8/v8-version.h b/android/x86/include/v8/v8-version.h
new file mode 100644
index 00000000..0889459c
--- /dev/null
+++ b/android/x86/include/v8/v8-version.h
@@ -0,0 +1,20 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INCLUDE_VERSION_H_  // V8_VERSION_H_ conflicts with src/version.h
+#define V8_INCLUDE_VERSION_H_
+
+// These macros define the version number for the current version.
+// NOTE these macros are used by some of the tool scripts and the build
+// system so their names cannot be changed without changing the scripts.
+#define V8_MAJOR_VERSION 6
+#define V8_MINOR_VERSION 0
+#define V8_BUILD_NUMBER 286
+#define V8_PATCH_LEVEL 52
+
+// Use 1 for candidates and 0 otherwise.
+// (Boolean macro values are not supported by all preprocessors.)
+#define V8_IS_CANDIDATE_VERSION 0
+
+#endif  // V8_INCLUDE_VERSION_H_
diff --git a/android/x86/include/v8/v8.h b/android/x86/include/v8/v8.h
new file mode 100644
index 00000000..da3cdfdc
--- /dev/null
+++ b/android/x86/include/v8/v8.h
@@ -0,0 +1,10155 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/** \mainpage V8 API Reference Guide
+ *
+ * V8 is Google's open source JavaScript engine.
+ *
+ * This set of documents provides reference material generated from the
+ * V8 header file, include/v8.h.
+ *
+ * For other documentation see http://code.google.com/apis/v8/
+ */
+
+#ifndef INCLUDE_V8_H_
+#define INCLUDE_V8_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "v8-version.h"  // NOLINT(build/include)
+#include "v8config.h"    // NOLINT(build/include)
+
+// We reserve the V8_* prefix for macros defined in V8 public API and
+// assume there are no name conflicts with the embedder's code.
+
+#ifdef V8_OS_WIN
+
+// Setup for Windows DLL export/import. When building the V8 DLL the
+// BUILDING_V8_SHARED needs to be defined. When building a program which uses
+// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
+// static library or building a program which uses the V8 static library neither
+// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
+#ifdef BUILDING_V8_SHARED
+# define V8_EXPORT __declspec(dllexport)
+#elif USING_V8_SHARED
+# define V8_EXPORT __declspec(dllimport)
+#else
+# define V8_EXPORT
+#endif  // BUILDING_V8_SHARED
+
+#else  // V8_OS_WIN
+
+// Setup for Linux shared library export.
+#if V8_HAS_ATTRIBUTE_VISIBILITY
+# ifdef BUILDING_V8_SHARED
+#  define V8_EXPORT __attribute__ ((visibility("default")))
+# else
+#  define V8_EXPORT
+# endif
+#else
+# define V8_EXPORT
+#endif
+
+#endif  // V8_OS_WIN
+
+/**
+ * The v8 JavaScript engine.
+ */
+namespace v8 {
+
+class AccessorSignature;
+class Array;
+class ArrayBuffer;
+class Boolean;
+class BooleanObject;
+class Context;
+class CpuProfiler;
+class Data;
+class Date;
+class External;
+class Function;
+class FunctionTemplate;
+class HeapProfiler;
+class ImplementationUtilities;
+class Int32;
+class Integer;
+class Isolate;
+template <class T>
+class Maybe;
+class Name;
+class Number;
+class NumberObject;
+class Object;
+class ObjectOperationDescriptor;
+class ObjectTemplate;
+class Platform;
+class Primitive;
+class Promise;
+class PropertyDescriptor;
+class Proxy;
+class RawOperationDescriptor;
+class Script;
+class SharedArrayBuffer;
+class Signature;
+class StartupData;
+class StackFrame;
+class StackTrace;
+class String;
+class StringObject;
+class Symbol;
+class SymbolObject;
+class Private;
+class Uint32;
+class Utils;
+class Value;
+class WasmCompiledModule;
+template <class T> class Local;
+template <class T>
+class MaybeLocal;
+template <class T> class Eternal;
+template<class T> class NonCopyablePersistentTraits;
+template<class T> class PersistentBase;
+template <class T, class M = NonCopyablePersistentTraits<T> >
+class Persistent;
+template <class T>
+class Global;
+template<class K, class V, class T> class PersistentValueMap;
+template <class K, class V, class T>
+class PersistentValueMapBase;
+template <class K, class V, class T>
+class GlobalValueMap;
+template<class V, class T> class PersistentValueVector;
+template<class T, class P> class WeakCallbackObject;
+class FunctionTemplate;
+class ObjectTemplate;
+template<typename T> class FunctionCallbackInfo;
+template<typename T> class PropertyCallbackInfo;
+class StackTrace;
+class StackFrame;
+class Isolate;
+class CallHandlerHelper;
+class EscapableHandleScope;
+template<typename T> class ReturnValue;
+
+namespace internal {
+class Arguments;
+class Heap;
+class HeapObject;
+class Isolate;
+class Object;
+struct StreamedSource;
+template<typename T> class CustomArguments;
+class PropertyCallbackArguments;
+class FunctionCallbackArguments;
+class GlobalHandles;
+}  // namespace internal
+
+namespace debug {
+class ConsoleCallArguments;
+}  // namespace debug
+
+// --- Handles ---
+
+#define TYPE_CHECK(T, S)                                       \
+  while (false) {                                              \
+    *(static_cast<T* volatile*>(0)) = static_cast<S*>(0);      \
+  }
+
+/**
+ * An object reference managed by the v8 garbage collector.
+ *
+ * All objects returned from v8 have to be tracked by the garbage
+ * collector so that it knows that the objects are still alive.  Also,
+ * because the garbage collector may move objects, it is unsafe to
+ * point directly to an object.  Instead, all objects are stored in
+ * handles which are known by the garbage collector and updated
+ * whenever an object moves.  Handles should always be passed by value
+ * (except in cases like out-parameters) and they should never be
+ * allocated on the heap.
+ *
+ * There are two types of handles: local and persistent handles.
+ *
+ * Local handles are light-weight and transient and typically used in
+ * local operations.  They are managed by HandleScopes. That means that a
+ * HandleScope must exist on the stack when they are created and that they are
+ * only valid inside of the HandleScope active during their creation.
+ * For passing a local handle to an outer HandleScope, an EscapableHandleScope
+ * and its Escape() method must be used.
+ *
+ * Persistent handles can be used when storing objects across several
+ * independent operations and have to be explicitly deallocated when they're no
+ * longer used.
+ *
+ * It is safe to extract the object stored in the handle by
+ * dereferencing the handle (for instance, to extract the Object* from
+ * a Local<Object>); the value will still be governed by a handle
+ * behind the scenes and the same rules apply to these values as to
+ * their handles.
+ */
+template <class T>
+class Local {
+ public:
+  V8_INLINE Local() : val_(0) {}
+  template <class S>
+  V8_INLINE Local(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    /**
+     * This check fails when trying to convert between incompatible
+     * handles. For example, converting from a Local<String> to a
+     * Local<Number>.
+     */
+    TYPE_CHECK(T, S);
+  }
+
+  /**
+   * Returns true if the handle is empty.
+   */
+  V8_INLINE bool IsEmpty() const { return val_ == 0; }
+
+  /**
+   * Sets the handle to be empty. IsEmpty() will then return true.
+   */
+  V8_INLINE void Clear() { val_ = 0; }
+
+  V8_INLINE T* operator->() const { return val_; }
+
+  V8_INLINE T* operator*() const { return val_; }
+
+  /**
+   * Checks whether two handles are the same.
+   * Returns true if both are empty, or if the objects
+   * to which they refer are identical.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  template <class S> V8_INLINE bool operator==(
+      const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == 0) return b == 0;
+    if (b == 0) return false;
+    return *a == *b;
+  }
+
+  /**
+   * Checks whether two handles are different.
+   * Returns true if only one of the handles is empty, or if
+   * the objects to which they refer are different.
+   * The handles' references are not checked.
+   */
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S> V8_INLINE bool operator!=(
+      const Persistent<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   * Cast a handle to a subclass, e.g. Local<Value> to Local<Object>.
+   * This is only valid if the handle actually refers to a value of the
+   * target type.
+   */
+  template <class S> V8_INLINE static Local<T> Cast(Local<S> that) {
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (that.IsEmpty()) return Local<T>();
+#endif
+    return Local<T>(T::Cast(*that));
+  }
+
+  /**
+   * Calling this is equivalent to Local<S>::Cast().
+   * In particular, this is only valid if the handle actually refers to a value
+   * of the target type.
+   */
+  template <class S>
+  V8_INLINE Local<S> As() const {
+    return Local<S>::Cast(*this);
+  }
+
+  /**
+   * Create a local handle for the content of another handle.
+   * The referee is kept alive by the local handle even when
+   * the original handle is destroyed/disposed.
+   */
+  V8_INLINE static Local<T> New(Isolate* isolate, Local<T> that);
+  V8_INLINE static Local<T> New(Isolate* isolate,
+                                const PersistentBase<T>& that);
+
+ private:
+  friend class Utils;
+  template<class F> friend class Eternal;
+  template<class F> friend class PersistentBase;
+  template<class F, class M> friend class Persistent;
+  template<class F> friend class Local;
+  template <class F>
+  friend class MaybeLocal;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  friend class String;
+  friend class Object;
+  friend class Context;
+  friend class Private;
+  template<class F> friend class internal::CustomArguments;
+  friend Local<Primitive> Undefined(Isolate* isolate);
+  friend Local<Primitive> Null(Isolate* isolate);
+  friend Local<Boolean> True(Isolate* isolate);
+  friend Local<Boolean> False(Isolate* isolate);
+  friend class HandleScope;
+  friend class EscapableHandleScope;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  template <class F>
+  friend class ReturnValue;
+
+  explicit V8_INLINE Local(T* that) : val_(that) {}
+  V8_INLINE static Local<T> New(Isolate* isolate, T* that);
+  T* val_;
+};
+
+
+#if !defined(V8_IMMINENT_DEPRECATION_WARNINGS)
+// Handle is an alias for Local for historical reasons.
+template <class T>
+using Handle = Local<T>;
+#endif
+
+
+/**
+ * A MaybeLocal<> is a wrapper around Local<> that enforces a check whether
+ * the Local<> is empty before it can be used.
+ *
+ * If an API method returns a MaybeLocal<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, an
+ * empty MaybeLocal is returned.
+ */
+template <class T>
+class MaybeLocal {
+ public:
+  V8_INLINE MaybeLocal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE MaybeLocal(Local<S> that)
+      : val_(reinterpret_cast<T*>(*that)) {
+    TYPE_CHECK(T, S);
+  }
+
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * |false| is returned and |out| is left untouched.
+   */
+  template <class S>
+  V8_WARN_UNUSED_RESULT V8_INLINE bool ToLocal(Local<S>* out) const {
+    out->val_ = IsEmpty() ? nullptr : this->val_;
+    return !IsEmpty();
+  }
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>. If this MaybeLocal<> is empty,
+   * V8 will crash the process.
+   */
+  V8_INLINE Local<T> ToLocalChecked();
+
+  /**
+   * Converts this MaybeLocal<> to a Local<>, using a default value if this
+   * MaybeLocal<> is empty.
+   */
+  template <class S>
+  V8_INLINE Local<S> FromMaybe(Local<S> default_value) const {
+    return IsEmpty() ? default_value : Local<S>(val_);
+  }
+
+ private:
+  T* val_;
+};
+
+/**
+ * Eternal handles are set-once handles that live for the lifetime of the
+ * isolate.
+ */
+template <class T> class Eternal {
+ public:
+  V8_INLINE Eternal() : val_(nullptr) {}
+  template <class S>
+  V8_INLINE Eternal(Isolate* isolate, Local<S> handle) : val_(nullptr) {
+    Set(isolate, handle);
+  }
+  // Can only be safely called if already set.
+  V8_INLINE Local<T> Get(Isolate* isolate) const;
+  V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
+  template<class S> V8_INLINE void Set(Isolate* isolate, Local<S> handle);
+
+ private:
+  T* val_;
+};
+
+
+static const int kInternalFieldsInWeakCallback = 2;
+static const int kEmbedderFieldsInWeakCallback = 2;
+
+template <typename T>
+class WeakCallbackInfo {
+ public:
+  typedef void (*Callback)(const WeakCallbackInfo<T>& data);
+
+  WeakCallbackInfo(Isolate* isolate, T* parameter,
+                   void* embedder_fields[kEmbedderFieldsInWeakCallback],
+                   Callback* callback)
+      : isolate_(isolate), parameter_(parameter), callback_(callback) {
+    for (int i = 0; i < kEmbedderFieldsInWeakCallback; ++i) {
+      embedder_fields_[i] = embedder_fields[i];
+    }
+  }
+
+  V8_INLINE Isolate* GetIsolate() const { return isolate_; }
+  V8_INLINE T* GetParameter() const { return parameter_; }
+  V8_INLINE void* GetInternalField(int index) const;
+
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField1() const) {
+    return embedder_fields_[0];
+  }
+  V8_INLINE V8_DEPRECATED("use indexed version",
+                          void* GetInternalField2() const) {
+    return embedder_fields_[1];
+  }
+
+  V8_DEPRECATED("Not realiable once SetSecondPassCallback() was used.",
+                bool IsFirstPass() const) {
+    return callback_ != nullptr;
+  }
+
+  // When first called, the embedder MUST Reset() the Global which triggered the
+  // callback. The Global itself is unusable for anything else. No v8 other api
+  // calls may be called in the first callback. Should additional work be
+  // required, the embedder must set a second pass callback, which will be
+  // called after all the initial callbacks are processed.
+  // Calling SetSecondPassCallback on the second pass will immediately crash.
+  void SetSecondPassCallback(Callback callback) const { *callback_ = callback; }
+
+ private:
+  Isolate* isolate_;
+  T* parameter_;
+  Callback* callback_;
+  void* embedder_fields_[kEmbedderFieldsInWeakCallback];
+};
+
+
+// kParameter will pass a void* parameter back to the callback, kInternalFields
+// will pass the first two internal fields back to the callback, kFinalizer
+// will pass a void* parameter back, but is invoked before the object is
+// actually collected, so it can be resurrected. In the last case, it is not
+// possible to request a second pass callback.
+enum class WeakCallbackType { kParameter, kInternalFields, kFinalizer };
+
+/**
+ * An object reference that is independent of any handle scope.  Where
+ * a Local handle only lives as long as the HandleScope in which it was
+ * allocated, a PersistentBase handle remains valid until it is explicitly
+ * disposed using Reset().
+ *
+ * A persistent handle contains a reference to a storage cell within
+ * the V8 engine which holds an object value and which is updated by
+ * the garbage collector whenever the object is moved.  A new storage
+ * cell can be created using the constructor or PersistentBase::Reset and
+ * existing handles can be disposed using PersistentBase::Reset.
+ *
+ */
+template <class T> class PersistentBase {
+ public:
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * IsEmpty() will return true after this call.
+   */
+  V8_INLINE void Reset();
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const Local<S>& other);
+
+  /**
+   * If non-empty, destroy the underlying storage cell
+   * and create a new one with the contents of other if other is non empty
+   */
+  template <class S>
+  V8_INLINE void Reset(Isolate* isolate, const PersistentBase<S>& other);
+
+  V8_INLINE bool IsEmpty() const { return val_ == NULL; }
+  V8_INLINE void Empty() { val_ = 0; }
+
+  V8_INLINE Local<T> Get(Isolate* isolate) const {
+    return Local<T>::New(isolate, *this);
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const PersistentBase<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator==(const Local<S>& that) const {
+    internal::Object** a = reinterpret_cast<internal::Object**>(this->val_);
+    internal::Object** b = reinterpret_cast<internal::Object**>(that.val_);
+    if (a == NULL) return b == NULL;
+    if (b == NULL) return false;
+    return *a == *b;
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const PersistentBase<S>& that) const {
+    return !operator==(that);
+  }
+
+  template <class S>
+  V8_INLINE bool operator!=(const Local<S>& that) const {
+    return !operator==(that);
+  }
+
+  /**
+   *  Install a finalization callback on this object.
+   *  NOTE: There is no guarantee as to *when* or even *if* the callback is
+   *  invoked. The invocation is performed solely on a best effort basis.
+   *  As always, GC-based finalization should *not* be relied upon for any
+   *  critical form of resource management!
+   */
+  template <typename P>
+  V8_INLINE void SetWeak(P* parameter,
+                         typename WeakCallbackInfo<P>::Callback callback,
+                         WeakCallbackType type);
+
+  /**
+   * Turns this handle into a weak phantom handle without finalization callback.
+   * The handle will be reset automatically when the garbage collector detects
+   * that the object is no longer reachable.
+   * A related function Isolate::NumberOfPhantomHandleResetsSinceLastCall
+   * returns how many phantom handles were reset by the garbage collector.
+   */
+  V8_INLINE void SetWeak();
+
+  template<typename P>
+  V8_INLINE P* ClearWeak();
+
+  // TODO(dcarney): remove this.
+  V8_INLINE void ClearWeak() { ClearWeak<void>(); }
+
+  /**
+   * Allows the embedder to tell the v8 garbage collector that a certain object
+   * is alive. Only allowed when the embedder is asked to trace its heap by
+   * EmbedderHeapTracer.
+   */
+  V8_INLINE void RegisterExternalReference(Isolate* isolate) const;
+
+  /**
+   * Marks the reference to this object independent. Garbage collector is free
+   * to ignore any object groups containing this object. Weak callback for an
+   * independent handle should not assume that it will be preceded by a global
+   * GC prologue callback or followed by a global GC epilogue callback.
+   */
+  V8_INLINE void MarkIndependent();
+
+  /**
+   * Marks the reference to this object as active. The scavenge garbage
+   * collection should not reclaim the objects marked as active.
+   * This bit is cleared after the each garbage collection pass.
+   */
+  V8_INLINE void MarkActive();
+
+  V8_INLINE bool IsIndependent() const;
+
+  /** Checks if the handle holds the only reference to an object. */
+  V8_INLINE bool IsNearDeath() const;
+
+  /** Returns true if the handle's reference is weak.  */
+  V8_INLINE bool IsWeak() const;
+
+  /**
+   * Assigns a wrapper class ID to the handle. See RetainedObjectInfo interface
+   * description in v8-profiler.h for details.
+   */
+  V8_INLINE void SetWrapperClassId(uint16_t class_id);
+
+  /**
+   * Returns the class ID previously assigned to this handle or 0 if no class ID
+   * was previously assigned.
+   */
+  V8_INLINE uint16_t WrapperClassId() const;
+
+  PersistentBase(const PersistentBase& other) = delete;  // NOLINT
+  void operator=(const PersistentBase&) = delete;
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template <class F>
+  friend class Global;
+  template<class F> friend class PersistentBase;
+  template<class F> friend class ReturnValue;
+  template <class F1, class F2, class F3>
+  friend class PersistentValueMapBase;
+  template<class F1, class F2> friend class PersistentValueVector;
+  friend class Object;
+
+  explicit V8_INLINE PersistentBase(T* val) : val_(val) {}
+  V8_INLINE static T* New(Isolate* isolate, T* that);
+
+  T* val_;
+};
+
+
+/**
+ * Default traits for Persistent. This class does not allow
+ * use of the copy constructor or assignment operator.
+ * At present kResetInDestructor is not set, but that will change in a future
+ * version.
+ */
+template<class T>
+class NonCopyablePersistentTraits {
+ public:
+  typedef Persistent<T, NonCopyablePersistentTraits<T> > NonCopyablePersistent;
+  static const bool kResetInDestructor = false;
+  template<class S, class M>
+  V8_INLINE static void Copy(const Persistent<S, M>& source,
+                             NonCopyablePersistent* dest) {
+    Uncompilable<Object>();
+  }
+  // TODO(dcarney): come up with a good compile error here.
+  template<class O> V8_INLINE static void Uncompilable() {
+    TYPE_CHECK(O, Primitive);
+  }
+};
+
+
+/**
+ * Helper class traits to allow copying and assignment of Persistent.
+ * This will clone the contents of storage cell, but not any of the flags, etc.
+ */
+template<class T>
+struct CopyablePersistentTraits {
+  typedef Persistent<T, CopyablePersistentTraits<T> > CopyablePersistent;
+  static const bool kResetInDestructor = true;
+  template<class S, class M>
+  static V8_INLINE void Copy(const Persistent<S, M>& source,
+                             CopyablePersistent* dest) {
+    // do nothing, just allow copy
+  }
+};
+
+
+/**
+ * A PersistentBase which allows copy and assignment.
+ *
+ * Copy, assignment and destructor behavior is controlled by the traits
+ * class M.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T, class M> class Persistent : public PersistentBase<T> {
+ public:
+  /**
+   * A Persistent with no storage cell.
+   */
+  V8_INLINE Persistent() : PersistentBase<T>(0) { }
+  /**
+   * Construct a Persistent from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Persistent(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Persistent from a Persistent.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S, class M2>
+  V8_INLINE Persistent(Isolate* isolate, const Persistent<S, M2>& that)
+    : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * The copy constructors and assignment operator create a Persistent
+   * exactly as the Persistent constructor, but the Copy function from the
+   * traits class is called, allowing the setting of flags based on the
+   * copied Persistent.
+   */
+  V8_INLINE Persistent(const Persistent& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent(const Persistent<S, M2>& that) : PersistentBase<T>(0) {
+    Copy(that);
+  }
+  V8_INLINE Persistent& operator=(const Persistent& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  template <class S, class M2>
+  V8_INLINE Persistent& operator=(const Persistent<S, M2>& that) { // NOLINT
+    Copy(that);
+    return *this;
+  }
+  /**
+   * The destructor will dispose the Persistent based on the
+   * kResetInDestructor flags in the traits class.  Since not calling dispose
+   * can result in a memory leak, it is recommended to always set this flag.
+   */
+  V8_INLINE ~Persistent() {
+    if (M::kResetInDestructor) this->Reset();
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE static Persistent<T>& Cast(const Persistent<S>& that) {  // NOLINT
+#ifdef V8_ENABLE_CHECKS
+    // If we're going to perform the type check then we have to check
+    // that the handle isn't empty before doing the checked cast.
+    if (!that.IsEmpty()) T::Cast(*that);
+#endif
+    return reinterpret_cast<Persistent<T>&>(const_cast<Persistent<S>&>(that));
+  }
+
+  // TODO(dcarney): this is pretty useless, fix or remove
+  template <class S>
+  V8_INLINE Persistent<S>& As() const {  // NOLINT
+    return Persistent<S>::Cast(*this);
+  }
+
+ private:
+  friend class Isolate;
+  friend class Utils;
+  template<class F> friend class Local;
+  template<class F1, class F2> friend class Persistent;
+  template<class F> friend class ReturnValue;
+
+  explicit V8_INLINE Persistent(T* that) : PersistentBase<T>(that) {}
+  V8_INLINE T* operator*() const { return this->val_; }
+  template<class S, class M2>
+  V8_INLINE void Copy(const Persistent<S, M2>& that);
+};
+
+
+/**
+ * A PersistentBase which has move semantics.
+ *
+ * Note: Persistent class hierarchy is subject to future changes.
+ */
+template <class T>
+class Global : public PersistentBase<T> {
+ public:
+  /**
+   * A Global with no storage cell.
+   */
+  V8_INLINE Global() : PersistentBase<T>(nullptr) {}
+  /**
+   * Construct a Global from a Local.
+   * When the Local is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, Local<S> that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Construct a Global from a PersistentBase.
+   * When the Persistent is non-empty, a new storage cell is created
+   * pointing to the same object, and no flags are set.
+   */
+  template <class S>
+  V8_INLINE Global(Isolate* isolate, const PersistentBase<S>& that)
+      : PersistentBase<T>(PersistentBase<T>::New(isolate, that.val_)) {
+    TYPE_CHECK(T, S);
+  }
+  /**
+   * Move constructor.
+   */
+  V8_INLINE Global(Global&& other) : PersistentBase<T>(other.val_) {  // NOLINT
+    other.val_ = nullptr;
+  }
+  V8_INLINE ~Global() { this->Reset(); }
+  /**
+   * Move via assignment.
+   */
+  template <class S>
+  V8_INLINE Global& operator=(Global<S>&& rhs) {  // NOLINT
+    TYPE_CHECK(T, S);
+    if (this != &rhs) {
+      this->Reset();
+      this->val_ = rhs.val_;
+      rhs.val_ = nullptr;
+    }
+    return *this;
+  }
+  /**
+   * Pass allows returning uniques from functions, etc.
+   */
+  Global Pass() { return static_cast<Global&&>(*this); }  // NOLINT
+
+  /*
+   * For compatibility with Chromium's base::Bind (base::Passed).
+   */
+  typedef void MoveOnlyTypeForCPP03;
+
+  Global(const Global&) = delete;
+  void operator=(const Global&) = delete;
+
+ private:
+  template <class F>
+  friend class ReturnValue;
+  V8_INLINE T* operator*() const { return this->val_; }
+};
+
+
+// UniquePersistent is an alias for Global for historical reason.
+template <class T>
+using UniquePersistent = Global<T>;
+
+
+ /**
+ * A stack-allocated class that governs a number of local handles.
+ * After a handle scope has been created, all local handles will be
+ * allocated within that handle scope until either the handle scope is
+ * deleted or another handle scope is created.  If there is already a
+ * handle scope and a new one is created, all allocations will take
+ * place in the new handle scope until it is deleted.  After that,
+ * new handles will again be allocated in the original handle scope.
+ *
+ * After the handle scope of a local handle has been deleted the
+ * garbage collector will no longer track the object stored in the
+ * handle and may deallocate it.  The behavior of accessing a handle
+ * for which the handle scope has been deleted is undefined.
+ */
+class V8_EXPORT HandleScope {
+ public:
+  explicit HandleScope(Isolate* isolate);
+
+  ~HandleScope();
+
+  /**
+   * Counts the number of allocated handles.
+   */
+  static int NumberOfHandles(Isolate* isolate);
+
+  V8_INLINE Isolate* GetIsolate() const {
+    return reinterpret_cast<Isolate*>(isolate_);
+  }
+
+  HandleScope(const HandleScope&) = delete;
+  void operator=(const HandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ protected:
+  V8_INLINE HandleScope() {}
+
+  void Initialize(Isolate* isolate);
+
+  static internal::Object** CreateHandle(internal::Isolate* isolate,
+                                         internal::Object* value);
+
+ private:
+  // Uses heap_object to obtain the current Isolate.
+  static internal::Object** CreateHandle(internal::HeapObject* heap_object,
+                                         internal::Object* value);
+
+  internal::Isolate* isolate_;
+  internal::Object** prev_next_;
+  internal::Object** prev_limit_;
+
+  // Local::New uses CreateHandle with an Isolate* parameter.
+  template<class F> friend class Local;
+
+  // Object::GetInternalField and Context::GetEmbedderData use CreateHandle with
+  // a HeapObject* in their shortcuts.
+  friend class Object;
+  friend class Context;
+};
+
+
+/**
+ * A HandleScope which first allocates a handle in the current scope
+ * which will be later filled with the escape value.
+ */
+class V8_EXPORT EscapableHandleScope : public HandleScope {
+ public:
+  explicit EscapableHandleScope(Isolate* isolate);
+  V8_INLINE ~EscapableHandleScope() {}
+
+  /**
+   * Pushes the value into the previous scope and returns a handle to it.
+   * Cannot be called twice.
+   */
+  template <class T>
+  V8_INLINE Local<T> Escape(Local<T> value) {
+    internal::Object** slot =
+        Escape(reinterpret_cast<internal::Object**>(*value));
+    return Local<T>(reinterpret_cast<T*>(slot));
+  }
+
+  EscapableHandleScope(const EscapableHandleScope&) = delete;
+  void operator=(const EscapableHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Object** Escape(internal::Object** escape_value);
+  internal::Object** escape_slot_;
+};
+
+/**
+ * A SealHandleScope acts like a handle scope in which no handle allocations
+ * are allowed. It can be useful for debugging handle leaks.
+ * Handles can be allocated within inner normal HandleScopes.
+ */
+class V8_EXPORT SealHandleScope {
+ public:
+  SealHandleScope(Isolate* isolate);
+  ~SealHandleScope();
+
+  SealHandleScope(const SealHandleScope&) = delete;
+  void operator=(const SealHandleScope&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  internal::Isolate* const isolate_;
+  internal::Object** prev_limit_;
+  int prev_sealed_level_;
+};
+
+
+// --- Special objects ---
+
+
+/**
+ * The superclass of values and API object templates.
+ */
+class V8_EXPORT Data {
+ private:
+  Data();
+};
+
+
+/**
+ * The optional attributes of ScriptOrigin.
+ */
+class ScriptOriginOptions {
+ public:
+  V8_INLINE ScriptOriginOptions(bool is_shared_cross_origin = false,
+                                bool is_opaque = false, bool is_wasm = false,
+                                bool is_module = false)
+      : flags_((is_shared_cross_origin ? kIsSharedCrossOrigin : 0) |
+               (is_wasm ? kIsWasm : 0) | (is_opaque ? kIsOpaque : 0) |
+               (is_module ? kIsModule : 0)) {}
+  V8_INLINE ScriptOriginOptions(int flags)
+      : flags_(flags &
+               (kIsSharedCrossOrigin | kIsOpaque | kIsWasm | kIsModule)) {}
+
+  bool IsSharedCrossOrigin() const {
+    return (flags_ & kIsSharedCrossOrigin) != 0;
+  }
+  bool IsOpaque() const { return (flags_ & kIsOpaque) != 0; }
+  bool IsWasm() const { return (flags_ & kIsWasm) != 0; }
+  bool IsModule() const { return (flags_ & kIsModule) != 0; }
+
+  int Flags() const { return flags_; }
+
+ private:
+  enum {
+    kIsSharedCrossOrigin = 1,
+    kIsOpaque = 1 << 1,
+    kIsWasm = 1 << 2,
+    kIsModule = 1 << 3
+  };
+  const int flags_;
+};
+
+/**
+ * The origin, within a file, of a script.
+ */
+class ScriptOrigin {
+ public:
+  V8_INLINE ScriptOrigin(
+      Local<Value> resource_name,
+      Local<Integer> resource_line_offset = Local<Integer>(),
+      Local<Integer> resource_column_offset = Local<Integer>(),
+      Local<Boolean> resource_is_shared_cross_origin = Local<Boolean>(),
+      Local<Integer> script_id = Local<Integer>(),
+      Local<Value> source_map_url = Local<Value>(),
+      Local<Boolean> resource_is_opaque = Local<Boolean>(),
+      Local<Boolean> is_wasm = Local<Boolean>(),
+      Local<Boolean> is_module = Local<Boolean>());
+
+  V8_INLINE Local<Value> ResourceName() const;
+  V8_INLINE Local<Integer> ResourceLineOffset() const;
+  V8_INLINE Local<Integer> ResourceColumnOffset() const;
+  /**
+    * Returns true for embedder's debugger scripts
+    */
+  V8_INLINE Local<Integer> ScriptID() const;
+  V8_INLINE Local<Value> SourceMapUrl() const;
+  V8_INLINE ScriptOriginOptions Options() const { return options_; }
+
+ private:
+  Local<Value> resource_name_;
+  Local<Integer> resource_line_offset_;
+  Local<Integer> resource_column_offset_;
+  ScriptOriginOptions options_;
+  Local<Integer> script_id_;
+  Local<Value> source_map_url_;
+};
+
+
+/**
+ * A compiled JavaScript script, not yet tied to a Context.
+ */
+class V8_EXPORT UnboundScript {
+ public:
+  /**
+   * Binds the script to the currently entered context.
+   */
+  Local<Script> BindToCurrentContext();
+
+  int GetId();
+  Local<Value> GetScriptName();
+
+  /**
+   * Data read from magic sourceURL comments.
+   */
+  Local<Value> GetSourceURL();
+  /**
+   * Data read from magic sourceMappingURL comments.
+   */
+  Local<Value> GetSourceMappingURL();
+
+  /**
+   * Returns zero based line number of the code_pos location in the script.
+   * -1 will be returned if no information available.
+   */
+  int GetLineNumber(int code_pos);
+
+  static const int kNoScriptId = 0;
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT Module {
+ public:
+  /**
+   * Returns the number of modules requested by this module.
+   */
+  int GetModuleRequestsLength() const;
+
+  /**
+   * Returns the ith module specifier in this module.
+   * i must be < GetModuleRequestsLength() and >= 0.
+   */
+  Local<String> GetModuleRequest(int i) const;
+
+  /**
+   * Returns the identity hash for this object.
+   */
+  int GetIdentityHash() const;
+
+  typedef MaybeLocal<Module> (*ResolveCallback)(Local<Context> context,
+                                                Local<String> specifier,
+                                                Local<Module> referrer);
+
+  /**
+   * ModuleDeclarationInstantiation
+   *
+   * Returns false if an exception occurred during instantiation. (In the case
+   * where the callback throws an exception, that exception is propagated.)
+   */
+  V8_WARN_UNUSED_RESULT bool Instantiate(Local<Context> context,
+                                         ResolveCallback callback);
+
+  /**
+   * ModuleEvaluation
+   *
+   * Returns the completion value.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Evaluate(Local<Context> context);
+};
+
+/**
+ * This is an unfinished experimental feature, and is only exposed
+ * here for internal testing purposes. DO NOT USE.
+ *
+ * A compiled JavaScript module.
+ */
+class V8_EXPORT DynamicImportResult {
+ public:
+  /**
+   * Resolves the promise with the namespace object of the given
+   * module.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportSuccess(Local<Context> context,
+                                                        Local<Module> module);
+
+  /**
+   * Rejects the promise with the given exception.
+   */
+  V8_WARN_UNUSED_RESULT bool FinishDynamicImportFailure(Local<Context> context,
+                                                        Local<Value> exception);
+};
+
+/**
+ * A compiled JavaScript script, tied to a Context which was active when the
+ * script was compiled.
+ */
+class V8_EXPORT Script {
+ public:
+  /**
+   * A shorthand for ScriptCompiler::Compile().
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Script> Compile(Local<String> source,
+                            ScriptOrigin* origin = nullptr));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Local<String> source,
+      ScriptOrigin* origin = nullptr);
+
+  static Local<Script> V8_DEPRECATE_SOON("Use maybe version",
+                                         Compile(Local<String> source,
+                                                 Local<String> file_name));
+
+  /**
+   * Runs the script returning the resulting value. It will be run in the
+   * context in which it was created (ScriptCompiler::CompileBound or
+   * UnboundScript::BindToCurrentContext()).
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Run());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Run(Local<Context> context);
+
+  /**
+   * Returns the corresponding context-unbound script.
+   */
+  Local<UnboundScript> GetUnboundScript();
+};
+
+
+/**
+ * For compiling scripts.
+ */
+class V8_EXPORT ScriptCompiler {
+ public:
+  /**
+   * Compilation data that the embedder can cache and pass back to speed up
+   * future compilations. The data is produced if the CompilerOptions passed to
+   * the compilation functions in ScriptCompiler contains produce_data_to_cache
+   * = true. The data to cache can then can be retrieved from
+   * UnboundScript.
+   */
+  struct V8_EXPORT CachedData {
+    enum BufferPolicy {
+      BufferNotOwned,
+      BufferOwned
+    };
+
+    CachedData()
+        : data(NULL),
+          length(0),
+          rejected(false),
+          buffer_policy(BufferNotOwned) {}
+
+    // If buffer_policy is BufferNotOwned, the caller keeps the ownership of
+    // data and guarantees that it stays alive until the CachedData object is
+    // destroyed. If the policy is BufferOwned, the given data will be deleted
+    // (with delete[]) when the CachedData object is destroyed.
+    CachedData(const uint8_t* data, int length,
+               BufferPolicy buffer_policy = BufferNotOwned);
+    ~CachedData();
+    // TODO(marja): Async compilation; add constructors which take a callback
+    // which will be called when V8 no longer needs the data.
+    const uint8_t* data;
+    int length;
+    bool rejected;
+    BufferPolicy buffer_policy;
+
+    // Prevent copying.
+    CachedData(const CachedData&) = delete;
+    CachedData& operator=(const CachedData&) = delete;
+  };
+
+  /**
+   * Source code which can be then compiled to a UnboundScript or Script.
+   */
+  class Source {
+   public:
+    // Source takes ownership of CachedData.
+    V8_INLINE Source(Local<String> source_string, const ScriptOrigin& origin,
+           CachedData* cached_data = NULL);
+    V8_INLINE Source(Local<String> source_string,
+                     CachedData* cached_data = NULL);
+    V8_INLINE ~Source();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the Source object is
+    // alive.
+    V8_INLINE const CachedData* GetCachedData() const;
+
+    V8_INLINE const ScriptOriginOptions& GetResourceOptions() const;
+
+    // Prevent copying.
+    Source(const Source&) = delete;
+    Source& operator=(const Source&) = delete;
+
+   private:
+    friend class ScriptCompiler;
+
+    Local<String> source_string;
+
+    // Origin information
+    Local<Value> resource_name;
+    Local<Integer> resource_line_offset;
+    Local<Integer> resource_column_offset;
+    ScriptOriginOptions resource_options;
+    Local<Value> source_map_url;
+
+    // Cached data from previous compilation (if a kConsume*Cache flag is
+    // set), or hold newly generated cache data (kProduce*Cache flags) are
+    // set when calling a compile method.
+    CachedData* cached_data;
+  };
+
+  /**
+   * For streaming incomplete script data to V8. The embedder should implement a
+   * subclass of this class.
+   */
+  class V8_EXPORT ExternalSourceStream {
+   public:
+    virtual ~ExternalSourceStream() {}
+
+    /**
+     * V8 calls this to request the next chunk of data from the embedder. This
+     * function will be called on a background thread, so it's OK to block and
+     * wait for the data, if the embedder doesn't have data yet. Returns the
+     * length of the data returned. When the data ends, GetMoreData should
+     * return 0. Caller takes ownership of the data.
+     *
+     * When streaming UTF-8 data, V8 handles multi-byte characters split between
+     * two data chunks, but doesn't handle multi-byte characters split between
+     * more than two data chunks. The embedder can avoid this problem by always
+     * returning at least 2 bytes of data.
+     *
+     * If the embedder wants to cancel the streaming, they should make the next
+     * GetMoreData call return 0. V8 will interpret it as end of data (and most
+     * probably, parsing will fail). The streaming task will return as soon as
+     * V8 has parsed the data it received so far.
+     */
+    virtual size_t GetMoreData(const uint8_t** src) = 0;
+
+    /**
+     * V8 calls this method to set a 'bookmark' at the current position in
+     * the source stream, for the purpose of (maybe) later calling
+     * ResetToBookmark. If ResetToBookmark is called later, then subsequent
+     * calls to GetMoreData should return the same data as they did when
+     * SetBookmark was called earlier.
+     *
+     * The embedder may return 'false' to indicate it cannot provide this
+     * functionality.
+     */
+    virtual bool SetBookmark();
+
+    /**
+     * V8 calls this to return to a previously set bookmark.
+     */
+    virtual void ResetToBookmark();
+  };
+
+
+  /**
+   * Source code which can be streamed into V8 in pieces. It will be parsed
+   * while streaming. It can be compiled after the streaming is complete.
+   * StreamedSource must be kept alive while the streaming task is ran (see
+   * ScriptStreamingTask below).
+   */
+  class V8_EXPORT StreamedSource {
+   public:
+    enum Encoding { ONE_BYTE, TWO_BYTE, UTF8 };
+
+    StreamedSource(ExternalSourceStream* source_stream, Encoding encoding);
+    ~StreamedSource();
+
+    // Ownership of the CachedData or its buffers is *not* transferred to the
+    // caller. The CachedData object is alive as long as the StreamedSource
+    // object is alive.
+    const CachedData* GetCachedData() const;
+
+    internal::StreamedSource* impl() const { return impl_; }
+
+    // Prevent copying.
+    StreamedSource(const StreamedSource&) = delete;
+    StreamedSource& operator=(const StreamedSource&) = delete;
+
+   private:
+    internal::StreamedSource* impl_;
+  };
+
+  /**
+   * A streaming task which the embedder must run on a background thread to
+   * stream scripts into V8. Returned by ScriptCompiler::StartStreamingScript.
+   */
+  class ScriptStreamingTask {
+   public:
+    virtual ~ScriptStreamingTask() {}
+    virtual void Run() = 0;
+  };
+
+  enum CompileOptions {
+    kNoCompileOptions = 0,
+    kProduceParserCache,
+    kConsumeParserCache,
+    kProduceCodeCache,
+    kConsumeCodeCache
+  };
+
+  /**
+   * Compiles the specified script (context-independent).
+   * Cached data as part of the source object can be optionally produced to be
+   * consumed later to speed up compilation of identical source scripts.
+   *
+   * Note that when producing cached data, the source must point to NULL for
+   * cached data. When consuming cached data, the cached data must have been
+   * produced by the same version of V8.
+   *
+   * \param source Script source code.
+   * \return Compiled script object (context independent; for running it must be
+   *   bound to a context).
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<UnboundScript> CompileUnbound(
+                           Isolate* isolate, Source* source,
+                           CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundScript(
+      Isolate* isolate, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles the specified script (bound to current context).
+   *
+   * \param source Script source code.
+   * \param pre_data Pre-parsing data, as obtained by ScriptData::PreCompile()
+   *   using pre_data speeds compilation if it's done multiple times.
+   *   Owned by caller, no references are kept when this function returns.
+   * \return Compiled script object, bound to the context that was active
+   *   when this function was called. When run it will always use this
+   *   context.
+   */
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<Script> Compile(Isolate* isolate, Source* source,
+                            CompileOptions options = kNoCompileOptions));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, Source* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Returns a task which streams script data into V8, or NULL if the script
+   * cannot be streamed. The user is responsible for running the task on a
+   * background thread and deleting it. When ran, the task starts parsing the
+   * script, and it will request data from the StreamedSource as needed. When
+   * ScriptStreamingTask::Run exits, all data has been streamed and the script
+   * can be compiled (see Compile below).
+   *
+   * This API allows to start the streaming with as little data as possible, and
+   * the remaining data (for example, the ScriptOrigin) is passed to Compile.
+   */
+  static ScriptStreamingTask* StartStreamingScript(
+      Isolate* isolate, StreamedSource* source,
+      CompileOptions options = kNoCompileOptions);
+
+  /**
+   * Compiles a streamed script (bound to current context).
+   *
+   * This can only be called after the streaming has finished
+   * (ScriptStreamingTask has been run). V8 doesn't construct the source string
+   * during streaming, so the embedder needs to pass the full source here.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<Script> Compile(Isolate* isolate,
+                                             StreamedSource* source,
+                                             Local<String> full_source_string,
+                                             const ScriptOrigin& origin));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Script> Compile(
+      Local<Context> context, StreamedSource* source,
+      Local<String> full_source_string, const ScriptOrigin& origin);
+
+  /**
+   * Return a version tag for CachedData for the current V8 version & flags.
+   *
+   * This value is meant only for determining whether a previously generated
+   * CachedData instance is still valid; the tag has no other meaing.
+   *
+   * Background: The data carried by CachedData may depend on the exact
+   *   V8 version number or current compiler flags. This means that when
+   *   persisting CachedData, the embedder must take care to not pass in
+   *   data from another V8 version, or the same version with different
+   *   features enabled.
+   *
+   *   The easiest way to do so is to clear the embedder's cache on any
+   *   such change.
+   *
+   *   Alternatively, this tag can be stored alongside the cached data and
+   *   compared when it is being used.
+   */
+  static uint32_t CachedDataVersionTag();
+
+  /**
+   * This is an unfinished experimental feature, and is only exposed
+   * here for internal testing purposes. DO NOT USE.
+   *
+   * Compile an ES module, returning a Module that encapsulates
+   * the compiled code.
+   *
+   * Corresponds to the ParseModule abstract operation in the
+   * ECMAScript specification.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Module> CompileModule(
+      Isolate* isolate, Source* source);
+
+  /**
+   * Compile a function for a given context. This is equivalent to running
+   *
+   * with (obj) {
+   *   return function(args) { ... }
+   * }
+   *
+   * It is possible to specify multiple context extensions (obj in the above
+   * example).
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Function> CompileFunctionInContext(
+                               Isolate* isolate, Source* source,
+                               Local<Context> context, size_t arguments_count,
+                               Local<String> arguments[],
+                               size_t context_extension_count,
+                               Local<Object> context_extensions[]));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Function> CompileFunctionInContext(
+      Local<Context> context, Source* source, size_t arguments_count,
+      Local<String> arguments[], size_t context_extension_count,
+      Local<Object> context_extensions[]);
+
+ private:
+  static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundInternal(
+      Isolate* isolate, Source* source, CompileOptions options);
+};
+
+
+/**
+ * An error message.
+ */
+class V8_EXPORT Message {
+ public:
+  Local<String> Get() const;
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<String> GetSourceLine() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> GetSourceLine(
+      Local<Context> context) const;
+
+  /**
+   * Returns the origin for the script from where the function causing the
+   * error originates.
+   */
+  ScriptOrigin GetScriptOrigin() const;
+
+  /**
+   * Returns the resource name for the script from where the function causing
+   * the error originates.
+   */
+  Local<Value> GetScriptResourceName() const;
+
+  /**
+   * Exception stack trace. By default stack traces are not captured for
+   * uncaught exceptions. SetCaptureStackTraceForUncaughtExceptions allows
+   * to change this option.
+   */
+  Local<StackTrace> GetStackTrace() const;
+
+  /**
+   * Returns the number, 1-based, of the line where the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetLineNumber() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetLineNumber(Local<Context> context) const;
+
+  /**
+   * Returns the index within the script of the first character where
+   * the error occurred.
+   */
+  int GetStartPosition() const;
+
+  /**
+   * Returns the index within the script of the last character where
+   * the error occurred.
+   */
+  int GetEndPosition() const;
+
+  /**
+   * Returns the error level of the message.
+   */
+  int ErrorLevel() const;
+
+  /**
+   * Returns the index within the line of the first character where
+   * the error occurred.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", int GetStartColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetStartColumn(Local<Context> context) const;
+
+  /**
+   * Returns the index within the line of the last character where
+   * the error occurred.
+   */
+  V8_DEPRECATED("Use maybe version", int GetEndColumn() const);
+  V8_WARN_UNUSED_RESULT Maybe<int> GetEndColumn(Local<Context> context) const;
+
+  /**
+   * Passes on the value set by the embedder when it fed the script from which
+   * this Message was generated to V8.
+   */
+  bool IsSharedCrossOrigin() const;
+  bool IsOpaque() const;
+
+  // TODO(1245381): Print to a string instead of on a FILE.
+  static void PrintCurrentStackTrace(Isolate* isolate, FILE* out);
+
+  static const int kNoLineNumberInfo = 0;
+  static const int kNoColumnInfo = 0;
+  static const int kNoScriptIdInfo = 0;
+};
+
+
+/**
+ * Representation of a JavaScript stack trace. The information collected is a
+ * snapshot of the execution stack and the information remains valid after
+ * execution continues.
+ */
+class V8_EXPORT StackTrace {
+ public:
+  /**
+   * Flags that determine what information is placed captured for each
+   * StackFrame when grabbing the current stack trace.
+   * Note: these options are deprecated and we always collect all available
+   * information (kDetailed).
+   */
+  enum StackTraceOptions {
+    kLineNumber = 1,
+    kColumnOffset = 1 << 1 | kLineNumber,
+    kScriptName = 1 << 2,
+    kFunctionName = 1 << 3,
+    kIsEval = 1 << 4,
+    kIsConstructor = 1 << 5,
+    kScriptNameOrSourceURL = 1 << 6,
+    kScriptId = 1 << 7,
+    kExposeFramesAcrossSecurityOrigins = 1 << 8,
+    kOverview = kLineNumber | kColumnOffset | kScriptName | kFunctionName,
+    kDetailed = kOverview | kIsEval | kIsConstructor | kScriptNameOrSourceURL
+  };
+
+  /**
+   * Returns a StackFrame at a particular index.
+   */
+  Local<StackFrame> GetFrame(uint32_t index) const;
+
+  /**
+   * Returns the number of StackFrames.
+   */
+  int GetFrameCount() const;
+
+  /**
+   * Returns StackTrace as a v8::Array that contains StackFrame objects.
+   */
+  V8_DEPRECATED("Use native API instead", Local<Array> AsArray());
+
+  /**
+   * Grab a snapshot of the current JavaScript execution stack.
+   *
+   * \param frame_limit The maximum number of stack frames we want to capture.
+   * \param options Enumerates the set of things we will capture for each
+   *   StackFrame.
+   */
+  static Local<StackTrace> CurrentStackTrace(
+      Isolate* isolate, int frame_limit, StackTraceOptions options = kDetailed);
+};
+
+
+/**
+ * A single JavaScript stack frame.
+ */
+class V8_EXPORT StackFrame {
+ public:
+  /**
+   * Returns the number, 1-based, of the line for the associate function call.
+   * This method will return Message::kNoLineNumberInfo if it is unable to
+   * retrieve the line number, or if kLineNumber was not passed as an option
+   * when capturing the StackTrace.
+   */
+  int GetLineNumber() const;
+
+  /**
+   * Returns the 1-based column offset on the line for the associated function
+   * call.
+   * This method will return Message::kNoColumnInfo if it is unable to retrieve
+   * the column number, or if kColumnOffset was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetColumn() const;
+
+  /**
+   * Returns the id of the script for the function for this StackFrame.
+   * This method will return Message::kNoScriptIdInfo if it is unable to
+   * retrieve the script id, or if kScriptId was not passed as an option when
+   * capturing the StackTrace.
+   */
+  int GetScriptId() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame.
+   */
+  Local<String> GetScriptName() const;
+
+  /**
+   * Returns the name of the resource that contains the script for the
+   * function for this StackFrame or sourceURL value if the script name
+   * is undefined and its source ends with //# sourceURL=... string or
+   * deprecated //@ sourceURL=... string.
+   */
+  Local<String> GetScriptNameOrSourceURL() const;
+
+  /**
+   * Returns the name of the function associated with this stack frame.
+   */
+  Local<String> GetFunctionName() const;
+
+  /**
+   * Returns whether or not the associated function is compiled via a call to
+   * eval().
+   */
+  bool IsEval() const;
+
+  /**
+   * Returns whether or not the associated function is called as a
+   * constructor via "new".
+   */
+  bool IsConstructor() const;
+
+  /**
+   * Returns whether or not the associated functions is defined in wasm.
+   */
+  bool IsWasm() const;
+};
+
+
+// A StateTag represents a possible state of the VM.
+enum StateTag { JS, GC, COMPILER, OTHER, EXTERNAL, IDLE };
+
+// A RegisterState represents the current state of registers used
+// by the sampling profiler API.
+struct RegisterState {
+  RegisterState() : pc(nullptr), sp(nullptr), fp(nullptr) {}
+  void* pc;  // Instruction pointer.
+  void* sp;  // Stack pointer.
+  void* fp;  // Frame pointer.
+};
+
+// The output structure filled up by GetStackSample API function.
+struct SampleInfo {
+  size_t frames_count;            // Number of frames collected.
+  StateTag vm_state;              // Current VM state.
+  void* external_callback_entry;  // External callback address if VM is
+                                  // executing an external callback.
+};
+
+/**
+ * A JSON Parser and Stringifier.
+ */
+class V8_EXPORT JSON {
+ public:
+  /**
+   * Tries to parse the string |json_string| and returns it as value if
+   * successful.
+   *
+   * \param json_string The string to parse.
+   * \return The corresponding value if successfully parsed.
+   */
+  static V8_DEPRECATED("Use the maybe version taking context",
+                       Local<Value> Parse(Local<String> json_string));
+  static V8_DEPRECATE_SOON("Use the maybe version taking context",
+                           MaybeLocal<Value> Parse(Isolate* isolate,
+                                                   Local<String> json_string));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> Parse(
+      Local<Context> context, Local<String> json_string);
+
+  /**
+   * Tries to stringify the JSON-serializable object |json_object| and returns
+   * it as string if successful.
+   *
+   * \param json_object The JSON-serializable object to stringify.
+   * \return The corresponding string if successfully stringified.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> Stringify(
+      Local<Context> context, Local<Object> json_object,
+      Local<String> gap = Local<String>());
+};
+
+/**
+ * Value serialization compatible with the HTML structured clone algorithm.
+ * The format is backward-compatible (i.e. safe to store to disk).
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueSerializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * Handles the case where a DataCloneError would be thrown in the structured
+     * clone spec. Other V8 embedders may throw some other appropriate exception
+     * type.
+     */
+    virtual void ThrowDataCloneError(Local<String> message) = 0;
+
+    /**
+     * The embedder overrides this method to write some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * Nothing<bool>() returned.
+     */
+    virtual Maybe<bool> WriteHostObject(Isolate* isolate, Local<Object> object);
+
+    /**
+     * Called when the ValueSerializer is going to serialize a
+     * SharedArrayBuffer object. The embedder must return an ID for the
+     * object, using the same ID if this SharedArrayBuffer has already been
+     * serialized in this buffer. When deserializing, this ID will be passed to
+     * ValueDeserializer::TransferSharedArrayBuffer as |transfer_id|.
+     *
+     * If the object cannot be serialized, an
+     * exception should be thrown and Nothing<uint32_t>() returned.
+     */
+    virtual Maybe<uint32_t> GetSharedArrayBufferId(
+        Isolate* isolate, Local<SharedArrayBuffer> shared_array_buffer);
+
+    virtual Maybe<uint32_t> GetWasmModuleTransferId(
+        Isolate* isolate, Local<WasmCompiledModule> module);
+    /**
+     * Allocates memory for the buffer of at least the size provided. The actual
+     * size (which may be greater or equal) is written to |actual_size|. If no
+     * buffer has been allocated yet, nullptr will be provided.
+     *
+     * If the memory cannot be allocated, nullptr should be returned.
+     * |actual_size| will be ignored. It is assumed that |old_buffer| is still
+     * valid in this case and has not been modified.
+     */
+    virtual void* ReallocateBufferMemory(void* old_buffer, size_t size,
+                                         size_t* actual_size);
+
+    /**
+     * Frees a buffer allocated with |ReallocateBufferMemory|.
+     */
+    virtual void FreeBufferMemory(void* buffer);
+  };
+
+  explicit ValueSerializer(Isolate* isolate);
+  ValueSerializer(Isolate* isolate, Delegate* delegate);
+  ~ValueSerializer();
+
+  /**
+   * Writes out a header, which includes the format version.
+   */
+  void WriteHeader();
+
+  /**
+   * Serializes a JavaScript value into the buffer.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> WriteValue(Local<Context> context,
+                                               Local<Value> value);
+
+  /**
+   * Returns the stored data. This serializer should not be used once the buffer
+   * is released. The contents are undefined if a previous write has failed.
+   */
+  V8_DEPRECATE_SOON("Use Release()", std::vector<uint8_t> ReleaseBuffer());
+
+  /**
+   * Returns the stored data (allocated using the delegate's
+   * AllocateBufferMemory) and its size. This serializer should not be used once
+   * the buffer is released. The contents are undefined if a previous write has
+   * failed.
+   */
+  V8_WARN_UNUSED_RESULT std::pair<uint8_t*, size_t> Release();
+
+  /**
+   * Marks an ArrayBuffer as havings its contents transferred out of band.
+   * Pass the corresponding ArrayBuffer in the deserializing context to
+   * ValueDeserializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   */
+  V8_DEPRECATE_SOON("Use Delegate::GetSharedArrayBufferId",
+                    void TransferSharedArrayBuffer(
+                        uint32_t transfer_id,
+                        Local<SharedArrayBuffer> shared_array_buffer));
+
+  /**
+   * Indicate whether to treat ArrayBufferView objects as host objects,
+   * i.e. pass them to Delegate::WriteHostObject. This should not be
+   * called when no Delegate was passed.
+   *
+   * The default is not to treat ArrayBufferViews as host objects.
+   */
+  void SetTreatArrayBufferViewsAsHostObjects(bool mode);
+
+  /**
+   * Write raw data in various common formats to the buffer.
+   * Note that integer types are written in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::WriteHostObject.
+   */
+  void WriteUint32(uint32_t value);
+  void WriteUint64(uint64_t value);
+  void WriteDouble(double value);
+  void WriteRawBytes(const void* source, size_t length);
+
+ private:
+  ValueSerializer(const ValueSerializer&) = delete;
+  void operator=(const ValueSerializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * Deserializes values from data written with ValueSerializer, or a compatible
+ * implementation.
+ *
+ * WARNING: This API is under development, and changes (including incompatible
+ * changes to the API or wire format) may occur without notice until this
+ * warning is removed.
+ */
+class V8_EXPORT ValueDeserializer {
+ public:
+  class V8_EXPORT Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    /**
+     * The embedder overrides this method to read some kind of host object, if
+     * possible. If not, a suitable exception should be thrown and
+     * MaybeLocal<Object>() returned.
+     */
+    virtual MaybeLocal<Object> ReadHostObject(Isolate* isolate);
+
+    /**
+     * Get a WasmCompiledModule given a transfer_id previously provided
+     * by ValueSerializer::GetWasmModuleTransferId
+     */
+    virtual MaybeLocal<WasmCompiledModule> GetWasmModuleFromId(
+        Isolate* isolate, uint32_t transfer_id);
+  };
+
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size);
+  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size,
+                    Delegate* delegate);
+  ~ValueDeserializer();
+
+  /**
+   * Reads and validates a header (including the format version).
+   * May, for example, reject an invalid or unsupported wire format.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> ReadHeader(Local<Context> context);
+
+  /**
+   * Deserializes a JavaScript value from the buffer.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> ReadValue(Local<Context> context);
+
+  /**
+   * Accepts the array buffer corresponding to the one passed previously to
+   * ValueSerializer::TransferArrayBuffer.
+   */
+  void TransferArrayBuffer(uint32_t transfer_id,
+                           Local<ArrayBuffer> array_buffer);
+
+  /**
+   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
+   * The id is not necessarily in the same namespace as unshared ArrayBuffer
+   * objects.
+   */
+  void TransferSharedArrayBuffer(uint32_t id,
+                                 Local<SharedArrayBuffer> shared_array_buffer);
+
+  /**
+   * Must be called before ReadHeader to enable support for reading the legacy
+   * wire format (i.e., which predates this being shipped).
+   *
+   * Don't use this unless you need to read data written by previous versions of
+   * blink::ScriptValueSerializer.
+   */
+  void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);
+
+  /**
+   * Expect inline wasm in the data stream (rather than in-memory transfer)
+   */
+  void SetExpectInlineWasm(bool allow_inline_wasm);
+
+  /**
+   * Reads the underlying wire format version. Likely mostly to be useful to
+   * legacy code reading old wire format versions. Must be called after
+   * ReadHeader.
+   */
+  uint32_t GetWireFormatVersion() const;
+
+  /**
+   * Reads raw data in various common formats to the buffer.
+   * Note that integer types are read in base-128 varint format, not with a
+   * binary copy. For use during an override of Delegate::ReadHostObject.
+   */
+  V8_WARN_UNUSED_RESULT bool ReadUint32(uint32_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadUint64(uint64_t* value);
+  V8_WARN_UNUSED_RESULT bool ReadDouble(double* value);
+  V8_WARN_UNUSED_RESULT bool ReadRawBytes(size_t length, const void** data);
+
+ private:
+  ValueDeserializer(const ValueDeserializer&) = delete;
+  void operator=(const ValueDeserializer&) = delete;
+
+  struct PrivateData;
+  PrivateData* private_;
+};
+
+/**
+ * A map whose keys are referenced weakly. It is similar to JavaScript WeakMap
+ * but can be created without entering a v8::Context and hence shouldn't
+ * escape to JavaScript.
+ */
+class V8_EXPORT NativeWeakMap : public Data {
+ public:
+  static Local<NativeWeakMap> New(Isolate* isolate);
+  void Set(Local<Value> key, Local<Value> value);
+  Local<Value> Get(Local<Value> key) const;
+  bool Has(Local<Value> key);
+  bool Delete(Local<Value> key);
+};
+
+
+// --- Value ---
+
+
+/**
+ * The superclass of all JavaScript values and objects.
+ */
+class V8_EXPORT Value : public Data {
+ public:
+  /**
+   * Returns true if this value is the undefined value.  See ECMA-262
+   * 4.3.10.
+   */
+  V8_INLINE bool IsUndefined() const;
+
+  /**
+   * Returns true if this value is the null value.  See ECMA-262
+   * 4.3.11.
+   */
+  V8_INLINE bool IsNull() const;
+
+  /**
+   * Returns true if this value is either the null or the undefined value.
+   * See ECMA-262
+   * 4.3.11. and 4.3.12
+   */
+  V8_INLINE bool IsNullOrUndefined() const;
+
+  /**
+  * Returns true if this value is true.
+  */
+  bool IsTrue() const;
+
+  /**
+   * Returns true if this value is false.
+   */
+  bool IsFalse() const;
+
+  /**
+   * Returns true if this value is a symbol or a string.
+   */
+  bool IsName() const;
+
+  /**
+   * Returns true if this value is an instance of the String type.
+   * See ECMA-262 8.4.
+   */
+  V8_INLINE bool IsString() const;
+
+  /**
+   * Returns true if this value is a symbol.
+   */
+  bool IsSymbol() const;
+
+  /**
+   * Returns true if this value is a function.
+   */
+  bool IsFunction() const;
+
+  /**
+   * Returns true if this value is an array. Note that it will return false for
+   * an Proxy for an array.
+   */
+  bool IsArray() const;
+
+  /**
+   * Returns true if this value is an object.
+   */
+  bool IsObject() const;
+
+  /**
+   * Returns true if this value is boolean.
+   */
+  bool IsBoolean() const;
+
+  /**
+   * Returns true if this value is a number.
+   */
+  bool IsNumber() const;
+
+  /**
+   * Returns true if this value is external.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this value is a 32-bit signed integer.
+   */
+  bool IsInt32() const;
+
+  /**
+   * Returns true if this value is a 32-bit unsigned integer.
+   */
+  bool IsUint32() const;
+
+  /**
+   * Returns true if this value is a Date.
+   */
+  bool IsDate() const;
+
+  /**
+   * Returns true if this value is an Arguments object.
+   */
+  bool IsArgumentsObject() const;
+
+  /**
+   * Returns true if this value is a Boolean object.
+   */
+  bool IsBooleanObject() const;
+
+  /**
+   * Returns true if this value is a Number object.
+   */
+  bool IsNumberObject() const;
+
+  /**
+   * Returns true if this value is a String object.
+   */
+  bool IsStringObject() const;
+
+  /**
+   * Returns true if this value is a Symbol object.
+   */
+  bool IsSymbolObject() const;
+
+  /**
+   * Returns true if this value is a NativeError.
+   */
+  bool IsNativeError() const;
+
+  /**
+   * Returns true if this value is a RegExp.
+   */
+  bool IsRegExp() const;
+
+  /**
+   * Returns true if this value is an async function.
+   */
+  bool IsAsyncFunction() const;
+
+  /**
+   * Returns true if this value is a Generator function.
+   */
+  bool IsGeneratorFunction() const;
+
+  /**
+   * Returns true if this value is a Generator object (iterator).
+   */
+  bool IsGeneratorObject() const;
+
+  /**
+   * Returns true if this value is a Promise.
+   */
+  bool IsPromise() const;
+
+  /**
+   * Returns true if this value is a Map.
+   */
+  bool IsMap() const;
+
+  /**
+   * Returns true if this value is a Set.
+   */
+  bool IsSet() const;
+
+  /**
+   * Returns true if this value is a Map Iterator.
+   */
+  bool IsMapIterator() const;
+
+  /**
+   * Returns true if this value is a Set Iterator.
+   */
+  bool IsSetIterator() const;
+
+  /**
+   * Returns true if this value is a WeakMap.
+   */
+  bool IsWeakMap() const;
+
+  /**
+   * Returns true if this value is a WeakSet.
+   */
+  bool IsWeakSet() const;
+
+  /**
+   * Returns true if this value is an ArrayBuffer.
+   */
+  bool IsArrayBuffer() const;
+
+  /**
+   * Returns true if this value is an ArrayBufferView.
+   */
+  bool IsArrayBufferView() const;
+
+  /**
+   * Returns true if this value is one of TypedArrays.
+   */
+  bool IsTypedArray() const;
+
+  /**
+   * Returns true if this value is an Uint8Array.
+   */
+  bool IsUint8Array() const;
+
+  /**
+   * Returns true if this value is an Uint8ClampedArray.
+   */
+  bool IsUint8ClampedArray() const;
+
+  /**
+   * Returns true if this value is an Int8Array.
+   */
+  bool IsInt8Array() const;
+
+  /**
+   * Returns true if this value is an Uint16Array.
+   */
+  bool IsUint16Array() const;
+
+  /**
+   * Returns true if this value is an Int16Array.
+   */
+  bool IsInt16Array() const;
+
+  /**
+   * Returns true if this value is an Uint32Array.
+   */
+  bool IsUint32Array() const;
+
+  /**
+   * Returns true if this value is an Int32Array.
+   */
+  bool IsInt32Array() const;
+
+  /**
+   * Returns true if this value is a Float32Array.
+   */
+  bool IsFloat32Array() const;
+
+  /**
+   * Returns true if this value is a Float64Array.
+   */
+  bool IsFloat64Array() const;
+
+  /**
+   * Returns true if this value is a DataView.
+   */
+  bool IsDataView() const;
+
+  /**
+   * Returns true if this value is a SharedArrayBuffer.
+   * This is an experimental feature.
+   */
+  bool IsSharedArrayBuffer() const;
+
+  /**
+   * Returns true if this value is a JavaScript Proxy.
+   */
+  bool IsProxy() const;
+
+  bool IsWebAssemblyCompiledModule() const;
+
+  V8_WARN_UNUSED_RESULT MaybeLocal<Boolean> ToBoolean(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Number> ToNumber(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ToDetailString(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> ToObject(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Integer> ToInteger(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToUint32(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT MaybeLocal<Int32> ToInt32(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Boolean> ToBoolean(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Number> ToNumber(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<String> ToString(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<String> ToDetailString(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Object> ToObject(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Integer> ToInteger(Isolate* isolate) const);
+  V8_DEPRECATED("Use maybe version",
+                Local<Uint32> ToUint32(Isolate* isolate) const);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Int32> ToInt32(Isolate* isolate) const);
+
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Boolean> ToBoolean() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Number> ToNumber() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<String> ToString() const);
+  inline V8_DEPRECATED("Use maybe version",
+                       Local<String> ToDetailString() const);
+  inline V8_DEPRECATE_SOON("Use maybe version", Local<Object> ToObject() const);
+  inline V8_DEPRECATE_SOON("Use maybe version",
+                           Local<Integer> ToInteger() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Uint32> ToUint32() const);
+  inline V8_DEPRECATED("Use maybe version", Local<Int32> ToInt32() const);
+
+  /**
+   * Attempts to convert a string to an array index.
+   * Returns an empty handle if the conversion fails.
+   */
+  V8_DEPRECATED("Use maybe version", Local<Uint32> ToArrayIndex() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Uint32> ToArrayIndex(
+      Local<Context> context) const;
+
+  V8_WARN_UNUSED_RESULT Maybe<bool> BooleanValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<double> NumberValue(Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int64_t> IntegerValue(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<uint32_t> Uint32Value(
+      Local<Context> context) const;
+  V8_WARN_UNUSED_RESULT Maybe<int32_t> Int32Value(Local<Context> context) const;
+
+  V8_DEPRECATE_SOON("Use maybe version", bool BooleanValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", double NumberValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", int64_t IntegerValue() const);
+  V8_DEPRECATE_SOON("Use maybe version", uint32_t Uint32Value() const);
+  V8_DEPRECATE_SOON("Use maybe version", int32_t Int32Value() const);
+
+  /** JS == */
+  V8_DEPRECATE_SOON("Use maybe version", bool Equals(Local<Value> that) const);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Equals(Local<Context> context,
+                                           Local<Value> that) const;
+  bool StrictEquals(Local<Value> that) const;
+  bool SameValue(Local<Value> that) const;
+
+  template <class T> V8_INLINE static Value* Cast(T* value);
+
+  Local<String> TypeOf(Isolate*);
+
+  Maybe<bool> InstanceOf(Local<Context> context, Local<Object> object);
+
+ private:
+  V8_INLINE bool QuickIsUndefined() const;
+  V8_INLINE bool QuickIsNull() const;
+  V8_INLINE bool QuickIsNullOrUndefined() const;
+  V8_INLINE bool QuickIsString() const;
+  bool FullIsUndefined() const;
+  bool FullIsNull() const;
+  bool FullIsString() const;
+};
+
+
+/**
+ * The superclass of primitive values.  See ECMA-262 4.3.2.
+ */
+class V8_EXPORT Primitive : public Value { };
+
+
+/**
+ * A primitive boolean value (ECMA-262, 4.3.14).  Either the true
+ * or false value.
+ */
+class V8_EXPORT Boolean : public Primitive {
+ public:
+  bool Value() const;
+  V8_INLINE static Boolean* Cast(v8::Value* obj);
+  V8_INLINE static Local<Boolean> New(Isolate* isolate, bool value);
+
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A superclass for symbols and strings.
+ */
+class V8_EXPORT Name : public Primitive {
+ public:
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses an inline property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  V8_INLINE static Name* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * A flag describing different modes of string creation.
+ *
+ * Aside from performance implications there are no differences between the two
+ * creation modes.
+ */
+enum class NewStringType {
+  /**
+   * Create a new string, always allocating new storage memory.
+   */
+  kNormal,
+
+  /**
+   * Acts as a hint that the string should be created in the
+   * old generation heap space and be deduplicated if an identical string
+   * already exists.
+   */
+  kInternalized
+};
+
+/**
+ * A JavaScript string value (ECMA-262, 4.3.17).
+ */
+class V8_EXPORT String : public Name {
+ public:
+  static const int kMaxLength = (1 << 28) - 16;
+
+  enum Encoding {
+    UNKNOWN_ENCODING = 0x1,
+    TWO_BYTE_ENCODING = 0x0,
+    ONE_BYTE_ENCODING = 0x8
+  };
+  /**
+   * Returns the number of characters (UTF-16 code units) in this string.
+   */
+  int Length() const;
+
+  /**
+   * Returns the number of bytes in the UTF-8 encoded
+   * representation of this string.
+   */
+  int Utf8Length() const;
+
+  /**
+   * Returns whether this string is known to contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Does not read the string.
+   * False negatives are possible.
+   */
+  bool IsOneByte() const;
+
+  /**
+   * Returns whether this string contain only one byte data,
+   * i.e. ISO-8859-1 code points.
+   * Will read the entire string in some cases.
+   */
+  bool ContainsOnlyOneByte() const;
+
+  /**
+   * Write the contents of the string to an external buffer.
+   * If no arguments are given, expects the buffer to be large
+   * enough to hold the entire string and NULL terminator. Copies
+   * the contents of the string and the NULL terminator into the
+   * buffer.
+   *
+   * WriteUtf8 will not write partial UTF-8 sequences, preferring to stop
+   * before the end of the buffer.
+   *
+   * Copies up to length characters into the output buffer.
+   * Only null-terminates if there is enough space in the buffer.
+   *
+   * \param buffer The buffer into which the string will be copied.
+   * \param start The starting position within the string at which
+   * copying begins.
+   * \param length The number of characters to copy from the string.  For
+   *    WriteUtf8 the number of bytes in the buffer.
+   * \param nchars_ref The number of characters written, can be NULL.
+   * \param options Various options that might affect performance of this or
+   *    subsequent operations.
+   * \return The number of characters copied to the buffer excluding the null
+   *    terminator.  For WriteUtf8: The number of bytes copied to the buffer
+   *    including the null terminator (if written).
+   */
+  enum WriteOptions {
+    NO_OPTIONS = 0,
+    HINT_MANY_WRITES_EXPECTED = 1,
+    NO_NULL_TERMINATION = 2,
+    PRESERVE_ONE_BYTE_NULL = 4,
+    // Used by WriteUtf8 to replace orphan surrogate code units with the
+    // unicode replacement character. Needs to be set to guarantee valid UTF-8
+    // output.
+    REPLACE_INVALID_UTF8 = 8
+  };
+
+  // 16-bit character codes.
+  int Write(uint16_t* buffer,
+            int start = 0,
+            int length = -1,
+            int options = NO_OPTIONS) const;
+  // One byte characters.
+  int WriteOneByte(uint8_t* buffer,
+                   int start = 0,
+                   int length = -1,
+                   int options = NO_OPTIONS) const;
+  // UTF-8 encoded characters.
+  int WriteUtf8(char* buffer,
+                int length = -1,
+                int* nchars_ref = NULL,
+                int options = NO_OPTIONS) const;
+
+  /**
+   * A zero length string.
+   */
+  V8_INLINE static Local<String> Empty(Isolate* isolate);
+
+  /**
+   * Returns true if the string is external
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if the string is both external and one-byte.
+   */
+  bool IsExternalOneByte() const;
+
+  class V8_EXPORT ExternalStringResourceBase {  // NOLINT
+   public:
+    virtual ~ExternalStringResourceBase() {}
+
+    virtual bool IsCompressible() const { return false; }
+
+   protected:
+    ExternalStringResourceBase() {}
+
+    /**
+     * Internally V8 will call this Dispose method when the external string
+     * resource is no longer needed. The default implementation will use the
+     * delete operator. This method can be overridden in subclasses to
+     * control how allocated external string resources are disposed.
+     */
+    virtual void Dispose() { delete this; }
+
+    // Disallow copying and assigning.
+    ExternalStringResourceBase(const ExternalStringResourceBase&) = delete;
+    void operator=(const ExternalStringResourceBase&) = delete;
+
+   private:
+    friend class internal::Heap;
+    friend class v8::String;
+  };
+
+  /**
+   * An ExternalStringResource is a wrapper around a two-byte string
+   * buffer that resides outside V8's heap. Implement an
+   * ExternalStringResource to manage the life cycle of the underlying
+   * buffer.  Note that the string data must be immutable.
+   */
+  class V8_EXPORT ExternalStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalStringResource() {}
+
+    /**
+     * The string data from the underlying buffer.
+     */
+    virtual const uint16_t* data() const = 0;
+
+    /**
+     * The length of the string. That is, the number of two-byte characters.
+     */
+    virtual size_t length() const = 0;
+
+   protected:
+    ExternalStringResource() {}
+  };
+
+  /**
+   * An ExternalOneByteStringResource is a wrapper around an one-byte
+   * string buffer that resides outside V8's heap. Implement an
+   * ExternalOneByteStringResource to manage the life cycle of the
+   * underlying buffer.  Note that the string data must be immutable
+   * and that the data must be Latin-1 and not UTF-8, which would require
+   * special treatment internally in the engine and do not allow efficient
+   * indexing.  Use String::New or convert to 16 bit data for non-Latin1.
+   */
+
+  class V8_EXPORT ExternalOneByteStringResource
+      : public ExternalStringResourceBase {
+   public:
+    /**
+     * Override the destructor to manage the life cycle of the underlying
+     * buffer.
+     */
+    virtual ~ExternalOneByteStringResource() {}
+    /** The string data from the underlying buffer.*/
+    virtual const char* data() const = 0;
+    /** The number of Latin-1 characters in the string.*/
+    virtual size_t length() const = 0;
+   protected:
+    ExternalOneByteStringResource() {}
+  };
+
+  /**
+   * If the string is an external string, return the ExternalStringResourceBase
+   * regardless of the encoding, otherwise return NULL.  The encoding of the
+   * string is returned in encoding_out.
+   */
+  V8_INLINE ExternalStringResourceBase* GetExternalStringResourceBase(
+      Encoding* encoding_out) const;
+
+  /**
+   * Get the ExternalStringResource for an external string.  Returns
+   * NULL if IsExternal() doesn't return true.
+   */
+  V8_INLINE ExternalStringResource* GetExternalStringResource() const;
+
+  /**
+   * Get the ExternalOneByteStringResource for an external one-byte string.
+   * Returns NULL if IsExternalOneByte() doesn't return true.
+   */
+  const ExternalOneByteStringResource* GetExternalOneByteStringResource() const;
+
+  V8_INLINE static String* Cast(v8::Value* obj);
+
+  // TODO(dcarney): remove with deprecation of New functions.
+  enum NewStringType {
+    kNormalString = static_cast<int>(v8::NewStringType::kNormal),
+    kInternalizedString = static_cast<int>(v8::NewStringType::kInternalized)
+  };
+
+  /** Allocates a new string from UTF-8 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromUtf8(Isolate* isolate, const char* data,
+                                NewStringType type = kNormalString,
+                                int length = -1));
+
+  /** Allocates a new string from UTF-8 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromUtf8(
+      Isolate* isolate, const char* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from Latin-1 data.*/
+  static V8_DEPRECATED(
+      "Use maybe version",
+      Local<String> NewFromOneByte(Isolate* isolate, const uint8_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from Latin-1 data.  Only returns an empty value
+   * when length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromOneByte(
+      Isolate* isolate, const uint8_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /** Allocates a new string from UTF-16 data.*/
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromTwoByte(Isolate* isolate, const uint16_t* data,
+                                   NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from UTF-16 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromTwoByte(
+      Isolate* isolate, const uint16_t* data, v8::NewStringType type,
+      int length = -1);
+
+  /**
+   * Creates a new string by concatenating the left and the right strings
+   * passed in as parameters.
+   */
+  static Local<String> Concat(Local<String> left, Local<String> right);
+
+  /**
+   * Creates a new external string using the data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATED("Use maybe version",
+                       Local<String> NewExternal(
+                           Isolate* isolate, ExternalStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalTwoByte(
+      Isolate* isolate, ExternalStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalStringResource* resource);
+
+  /**
+   * Creates a new external string using the one-byte data defined in the given
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed by calling its Dispose method. The caller of
+   * this function should not otherwise delete or modify the resource. Neither
+   * should the underlying buffer be deallocated or modified except through the
+   * destructor of the external string resource.
+   */
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewExternal(Isolate* isolate,
+                                ExternalOneByteStringResource* resource));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewExternalOneByte(
+      Isolate* isolate, ExternalOneByteStringResource* resource);
+
+  /**
+   * Associate an external string resource with this string by transforming it
+   * in place so that existing references to this string in the JavaScript heap
+   * will use the external string resource. The external string resource's
+   * character contents need to be equivalent to this string.
+   * Returns true if the string has been changed to be an external string.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
+   */
+  bool MakeExternal(ExternalOneByteStringResource* resource);
+
+  /**
+   * Returns true if this string can be made external.
+   */
+  bool CanMakeExternal();
+
+  /**
+   * Converts an object to a UTF-8-encoded character array.  Useful if
+   * you want to print the object.  If conversion to a string fails
+   * (e.g. due to an exception in the toString() method of the object)
+   * then the length() method returns 0 and the * operator returns
+   * NULL.
+   */
+  class V8_EXPORT Utf8Value {
+   public:
+    explicit Utf8Value(Local<v8::Value> obj);
+    ~Utf8Value();
+    char* operator*() { return str_; }
+    const char* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Utf8Value(const Utf8Value&) = delete;
+    void operator=(const Utf8Value&) = delete;
+
+   private:
+    char* str_;
+    int length_;
+  };
+
+  /**
+   * Converts an object to a two-byte (UTF-16-encoded) string.
+   * If conversion to a string fails (eg. due to an exception in the toString()
+   * method of the object) then the length() method returns 0 and the * operator
+   * returns NULL.
+   */
+  class V8_EXPORT Value {
+   public:
+    explicit Value(Local<v8::Value> obj);
+    ~Value();
+    uint16_t* operator*() { return str_; }
+    const uint16_t* operator*() const { return str_; }
+    int length() const { return length_; }
+
+    // Disallow copying and assigning.
+    Value(const Value&) = delete;
+    void operator=(const Value&) = delete;
+
+   private:
+    uint16_t* str_;
+    int length_;
+  };
+
+ private:
+  void VerifyExternalStringResourceBase(ExternalStringResourceBase* v,
+                                        Encoding encoding) const;
+  void VerifyExternalStringResource(ExternalStringResource* val) const;
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript symbol (ECMA-262 edition 6)
+ */
+class V8_EXPORT Symbol : public Name {
+ public:
+  /**
+   * Returns the print name string of the symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a symbol. If name is not empty, it will be used as the description.
+   */
+  static Local<Symbol> New(Isolate* isolate,
+                           Local<String> name = Local<String>());
+
+  /**
+   * Access global symbol registry.
+   * Note that symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys.
+   */
+  static Local<Symbol> For(Isolate *isolate, Local<String> name);
+
+  /**
+   * Retrieve a global symbol. Similar to |For|, but using a separate
+   * registry that is not accessible by (and cannot clash with) JavaScript code.
+   */
+  static Local<Symbol> ForApi(Isolate *isolate, Local<String> name);
+
+  // Well-known symbols
+  static Local<Symbol> GetHasInstance(Isolate* isolate);
+  static Local<Symbol> GetIsConcatSpreadable(Isolate* isolate);
+  static Local<Symbol> GetIterator(Isolate* isolate);
+  static Local<Symbol> GetMatch(Isolate* isolate);
+  static Local<Symbol> GetReplace(Isolate* isolate);
+  static Local<Symbol> GetSearch(Isolate* isolate);
+  static Local<Symbol> GetSplit(Isolate* isolate);
+  static Local<Symbol> GetToPrimitive(Isolate* isolate);
+  static Local<Symbol> GetToStringTag(Isolate* isolate);
+  static Local<Symbol> GetUnscopables(Isolate* isolate);
+
+  V8_INLINE static Symbol* Cast(Value* obj);
+
+ private:
+  Symbol();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A private symbol
+ *
+ * This is an experimental feature. Use at your own risk.
+ */
+class V8_EXPORT Private : public Data {
+ public:
+  /**
+   * Returns the print name string of the private symbol, or undefined if none.
+   */
+  Local<Value> Name() const;
+
+  /**
+   * Create a private symbol. If name is not empty, it will be the description.
+   */
+  static Local<Private> New(Isolate* isolate,
+                            Local<String> name = Local<String>());
+
+  /**
+   * Retrieve a global private symbol. If a symbol with this name has not
+   * been retrieved in the same isolate before, it is created.
+   * Note that private symbols created this way are never collected, so
+   * they should only be used for statically fixed properties.
+   * Also, there is only one global name space for the names used as keys.
+   * To minimize the potential for clashes, use qualified names as keys,
+   * e.g., "Class#property".
+   */
+  static Local<Private> ForApi(Isolate* isolate, Local<String> name);
+
+ private:
+  Private();
+};
+
+
+/**
+ * A JavaScript number value (ECMA-262, 4.3.20)
+ */
+class V8_EXPORT Number : public Primitive {
+ public:
+  double Value() const;
+  static Local<Number> New(Isolate* isolate, double value);
+  V8_INLINE static Number* Cast(v8::Value* obj);
+ private:
+  Number();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a signed integer.
+ */
+class V8_EXPORT Integer : public Number {
+ public:
+  static Local<Integer> New(Isolate* isolate, int32_t value);
+  static Local<Integer> NewFromUnsigned(Isolate* isolate, uint32_t value);
+  int64_t Value() const;
+  V8_INLINE static Integer* Cast(v8::Value* obj);
+ private:
+  Integer();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit signed integer.
+ */
+class V8_EXPORT Int32 : public Integer {
+ public:
+  int32_t Value() const;
+  V8_INLINE static Int32* Cast(v8::Value* obj);
+
+ private:
+  Int32();
+  static void CheckCast(v8::Value* obj);
+};
+
+
+/**
+ * A JavaScript value representing a 32-bit unsigned integer.
+ */
+class V8_EXPORT Uint32 : public Integer {
+ public:
+  uint32_t Value() const;
+  V8_INLINE static Uint32* Cast(v8::Value* obj);
+
+ private:
+  Uint32();
+  static void CheckCast(v8::Value* obj);
+};
+
+/**
+ * PropertyAttribute.
+ */
+enum PropertyAttribute {
+  /** None. **/
+  None = 0,
+  /** ReadOnly, i.e., not writable. **/
+  ReadOnly = 1 << 0,
+  /** DontEnum, i.e., not enumerable. **/
+  DontEnum = 1 << 1,
+  /** DontDelete, i.e., not configurable. **/
+  DontDelete = 1 << 2
+};
+
+/**
+ * Accessor[Getter|Setter] are used as callback functions when
+ * setting|getting a particular property. See Object and ObjectTemplate's
+ * method SetAccessor.
+ */
+typedef void (*AccessorGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+typedef void (*AccessorNameGetterCallback)(
+    Local<Name> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+typedef void (*AccessorSetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+typedef void (*AccessorNameSetterCallback)(
+    Local<Name> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<void>& info);
+
+
+/**
+ * Access control specifications.
+ *
+ * Some accessors should be accessible across contexts.  These
+ * accessors have an explicit access control parameter which specifies
+ * the kind of cross-context access that should be allowed.
+ *
+ * TODO(dcarney): Remove PROHIBITS_OVERWRITING as it is now unused.
+ */
+enum AccessControl {
+  DEFAULT               = 0,
+  ALL_CAN_READ          = 1,
+  ALL_CAN_WRITE         = 1 << 1,
+  PROHIBITS_OVERWRITING = 1 << 2
+};
+
+/**
+ * Property filter bits. They can be or'ed to build a composite filter.
+ */
+enum PropertyFilter {
+  ALL_PROPERTIES = 0,
+  ONLY_WRITABLE = 1,
+  ONLY_ENUMERABLE = 2,
+  ONLY_CONFIGURABLE = 4,
+  SKIP_STRINGS = 8,
+  SKIP_SYMBOLS = 16
+};
+
+/**
+ * Keys/Properties filter enums:
+ *
+ * KeyCollectionMode limits the range of collected properties. kOwnOnly limits
+ * the collected properties to the given Object only. kIncludesPrototypes will
+ * include all keys of the objects's prototype chain as well.
+ */
+enum class KeyCollectionMode { kOwnOnly, kIncludePrototypes };
+
+/**
+ * kIncludesIndices allows for integer indices to be collected, while
+ * kSkipIndices will exclude integer indicies from being collected.
+ */
+enum class IndexFilter { kIncludeIndices, kSkipIndices };
+
+/**
+ * Integrity level for objects.
+ */
+enum class IntegrityLevel { kFrozen, kSealed };
+
+/**
+ * A JavaScript object (ECMA-262, 4.3.3)
+ */
+class V8_EXPORT Object : public Value {
+ public:
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(Local<Value> key, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context,
+                                        Local<Value> key, Local<Value> value);
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool Set(uint32_t index, Local<Value> value));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Set(Local<Context> context, uint32_t index,
+                                        Local<Value> value);
+
+  // Implements CreateDataProperty (ECMA-262, 7.3.4).
+  //
+  // Defines a configurable, writable, enumerable property with the given value
+  // on the object unless the property already exists and is not configurable
+  // or the object is not extensible.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       Local<Name> key,
+                                                       Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> CreateDataProperty(Local<Context> context,
+                                                       uint32_t index,
+                                                       Local<Value> value);
+
+  // Implements DefineOwnProperty.
+  //
+  // In general, CreateDataProperty will be faster, however, does not allow
+  // for specifying attributes.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineOwnProperty(
+      Local<Context> context, Local<Name> key, Local<Value> value,
+      PropertyAttribute attributes = None);
+
+  // Implements Object.DefineProperty(O, P, Attributes), see Ecma-262 19.1.2.4.
+  //
+  // The defineProperty function is used to add an own property or
+  // update the attributes of an existing own property of an object.
+  //
+  // Both data and accessor descriptors can be used.
+  //
+  // In general, CreateDataProperty is faster, however, does not allow
+  // for specifying attributes or an accessor descriptor.
+  //
+  // The PropertyDescriptor can change when redefining a property.
+  //
+  // Returns true on success.
+  V8_WARN_UNUSED_RESULT Maybe<bool> DefineProperty(
+      Local<Context> context, Local<Name> key, PropertyDescriptor& descriptor);
+
+  // Sets an own property on this object bypassing interceptors and
+  // overriding accessors or read-only properties.
+  //
+  // Note that if the object has an interceptor the property will be set
+  // locally, but since the interceptor takes precedence the local property
+  // will only be returned if the interceptor doesn't return a value.
+  //
+  // Note also that this only works for named properties.
+  V8_DEPRECATED("Use CreateDataProperty / DefineOwnProperty",
+                bool ForceSet(Local<Value> key, Local<Value> value,
+                              PropertyAttribute attribs = None));
+  V8_DEPRECATE_SOON("Use CreateDataProperty / DefineOwnProperty",
+                    Maybe<bool> ForceSet(Local<Context> context,
+                                         Local<Value> key, Local<Value> value,
+                                         PropertyAttribute attribs = None));
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(Local<Value> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", Local<Value> Get(uint32_t index));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              uint32_t index);
+
+  /**
+   * Gets the property attributes of a property which can be None or
+   * any combination of ReadOnly, DontEnum and DontDelete. Returns
+   * None when the property doesn't exist.
+   */
+  V8_DEPRECATED("Use maybe version",
+                PropertyAttribute GetPropertyAttributes(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetPropertyAttributes(
+      Local<Context> context, Local<Value> key);
+
+  /**
+   * Returns Object.getOwnPropertyDescriptor as per ES2016 section 19.1.2.6.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetOwnPropertyDescriptor(Local<Name> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetOwnPropertyDescriptor(
+      Local<Context> context, Local<Name> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Has(Local<Value> key));
+  /**
+   * Object::Has() calls the abstract operation HasProperty(O, P) described
+   * in ECMA-262, 7.3.10. Has() returns
+   * true, if the object has the property, either own or on the prototype chain.
+   * Interceptors, i.e., PropertyQueryCallbacks, are called if present.
+   *
+   * Has() has the same side effects as JavaScript's `variable in object`.
+   * For example, calling Has() on a revoked proxy will throw an exception.
+   *
+   * \note Has() converts the key to a name, which possibly calls back into
+   * JavaScript.
+   *
+   * See also v8::Object::HasOwnProperty() and
+   * v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+
+  V8_DEPRECATE_SOON("Use maybe version", bool Delete(Local<Value> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  V8_DEPRECATED("Use maybe version", bool Has(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        uint32_t index);
+
+  V8_DEPRECATED("Use maybe version", bool Delete(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           uint32_t index);
+
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<String> name,
+                                 AccessorGetterCallback getter,
+                                 AccessorSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_DEPRECATED("Use maybe version",
+                bool SetAccessor(Local<Name> name,
+                                 AccessorNameGetterCallback getter,
+                                 AccessorNameSetterCallback setter = 0,
+                                 Local<Value> data = Local<Value>(),
+                                 AccessControl settings = DEFAULT,
+                                 PropertyAttribute attribute = None));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetAccessor(Local<Context> context,
+                          Local<Name> name,
+                          AccessorNameGetterCallback getter,
+                          AccessorNameSetterCallback setter = 0,
+                          MaybeLocal<Value> data = MaybeLocal<Value>(),
+                          AccessControl settings = DEFAULT,
+                          PropertyAttribute attribute = None);
+
+  void SetAccessorProperty(Local<Name> name, Local<Function> getter,
+                           Local<Function> setter = Local<Function>(),
+                           PropertyAttribute attribute = None,
+                           AccessControl settings = DEFAULT);
+
+  /**
+   * Sets a native data property like Template::SetNativeDataProperty, but
+   * this method sets on this object directly.
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetNativeDataProperty(
+      Local<Context> context, Local<Name> name,
+      AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = nullptr,
+      Local<Value> data = Local<Value>(), PropertyAttribute attributes = None);
+
+  /**
+   * Functionality for private properties.
+   * This is an experimental feature, use at your own risk.
+   * Note: Private properties are not inherited. Do not rely on this, since it
+   * may change.
+   */
+  Maybe<bool> HasPrivate(Local<Context> context, Local<Private> key);
+  Maybe<bool> SetPrivate(Local<Context> context, Local<Private> key,
+                         Local<Value> value);
+  Maybe<bool> DeletePrivate(Local<Context> context, Local<Private> key);
+  MaybeLocal<Value> GetPrivate(Local<Context> context, Local<Private> key);
+
+  /**
+   * Returns an array containing the names of the enumerable properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetPropertyNames(
+      Local<Context> context, KeyCollectionMode mode,
+      PropertyFilter property_filter, IndexFilter index_filter);
+
+  /**
+   * This function has the same functionality as GetPropertyNames but
+   * the returned array doesn't contain the names of properties from
+   * prototype objects.
+   */
+  V8_DEPRECATE_SOON("Use maybe version", Local<Array> GetOwnPropertyNames());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context);
+
+  /**
+   * Returns an array containing the names of the filtered properties
+   * of this object, including properties from prototype objects.  The
+   * array returned by this method contains the same values as would
+   * be enumerated by a for-in statement over this object.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Array> GetOwnPropertyNames(
+      Local<Context> context, PropertyFilter filter);
+
+  /**
+   * Get the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  Local<Value> GetPrototype();
+
+  /**
+   * Set the prototype object.  This does not skip objects marked to
+   * be skipped by __proto__ and it does not consult the security
+   * handler.
+   */
+  V8_DEPRECATED("Use maybe version", bool SetPrototype(Local<Value> prototype));
+  V8_WARN_UNUSED_RESULT Maybe<bool> SetPrototype(Local<Context> context,
+                                                 Local<Value> prototype);
+
+  /**
+   * Finds an instance of the given function template in the prototype
+   * chain.
+   */
+  Local<Object> FindInstanceInPrototypeChain(Local<FunctionTemplate> tmpl);
+
+  /**
+   * Call builtin Object.prototype.toString on this object.
+   * This is different from Value::ToString() that may call
+   * user-defined toString function. This one does not.
+   */
+  V8_DEPRECATED("Use maybe version", Local<String> ObjectProtoToString());
+  V8_WARN_UNUSED_RESULT MaybeLocal<String> ObjectProtoToString(
+      Local<Context> context);
+
+  /**
+   * Returns the name of the function invoked as a constructor for this object.
+   */
+  Local<String> GetConstructorName();
+
+  /**
+   * Sets the integrity level of the object.
+   */
+  Maybe<bool> SetIntegrityLevel(Local<Context> context, IntegrityLevel level);
+
+  /** Gets the number of internal fields for this Object. */
+  int InternalFieldCount();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static int InternalFieldCount(
+      const PersistentBase<Object>& object) {
+    return object.val_->InternalFieldCount();
+  }
+
+  /** Gets the value from an internal field. */
+  V8_INLINE Local<Value> GetInternalField(int index);
+
+  /** Sets the value in an internal field. */
+  void SetInternalField(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from an internal field. This field
+   * must have been set by SetAlignedPointerInInternalField, everything else
+   * leads to undefined behavior.
+   */
+  V8_INLINE void* GetAlignedPointerFromInternalField(int index);
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static void* GetAlignedPointerFromInternalField(
+      const PersistentBase<Object>& object, int index) {
+    return object.val_->GetAlignedPointerFromInternalField(index);
+  }
+
+  /**
+   * Sets a 2-byte-aligned native pointer in an internal field. To retrieve such
+   * a field, GetAlignedPointerFromInternalField must be used, everything else
+   * leads to undefined behavior.
+   */
+  void SetAlignedPointerInInternalField(int index, void* value);
+  void SetAlignedPointerInInternalFields(int argc, int indices[],
+                                         void* values[]);
+
+  // Testers for local properties.
+  V8_DEPRECATED("Use maybe version", bool HasOwnProperty(Local<String> key));
+
+  /**
+   * HasOwnProperty() is like JavaScript's Object.prototype.hasOwnProperty().
+   *
+   * See also v8::Object::Has() and v8::Object::HasRealNamedProperty().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   Local<Name> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasOwnProperty(Local<Context> context,
+                                                   uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedProperty(Local<String> key));
+  /**
+   * Use HasRealNamedProperty() if you want to check if an object has an own
+   * property without causing side effects, i.e., without calling interceptors.
+   *
+   * This function is similar to v8::Object::HasOwnProperty(), but it does not
+   * call interceptors.
+   *
+   * \note Consider using non-masking interceptors, i.e., the interceptors are
+   * not called if the receiver has the real named property. See
+   * `v8::PropertyHandlerFlags::kNonMasking`.
+   *
+   * See also v8::Object::Has().
+   */
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedProperty(Local<Context> context,
+                                                         Local<Name> key);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealIndexedProperty(uint32_t index));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealIndexedProperty(
+      Local<Context> context, uint32_t index);
+  V8_DEPRECATE_SOON("Use maybe version",
+                    bool HasRealNamedCallbackProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<bool> HasRealNamedCallbackProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Local<Value> GetRealNamedPropertyInPrototypeChain(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedPropertyInPrototypeChain(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property in the prototype chain,
+   * which can be None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED(
+      "Use maybe version",
+      Maybe<PropertyAttribute> GetRealNamedPropertyAttributesInPrototypeChain(
+          Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute>
+  GetRealNamedPropertyAttributesInPrototypeChain(Local<Context> context,
+                                                 Local<Name> key);
+
+  /**
+   * If result.IsEmpty() no real property was located on the object or
+   * in the prototype chain.
+   * This means interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> GetRealNamedProperty(Local<String> key));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> GetRealNamedProperty(
+      Local<Context> context, Local<Name> key);
+
+  /**
+   * Gets the property attributes of a real property which can be
+   * None or any combination of ReadOnly, DontEnum and DontDelete.
+   * Interceptors in the prototype chain are not called.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+                    Local<String> key));
+  V8_WARN_UNUSED_RESULT Maybe<PropertyAttribute> GetRealNamedPropertyAttributes(
+      Local<Context> context, Local<Name> key);
+
+  /** Tests for a named lookup interceptor.*/
+  bool HasNamedLookupInterceptor();
+
+  /** Tests for an index lookup interceptor.*/
+  bool HasIndexedLookupInterceptor();
+
+  /**
+   * Returns the identity hash for this object. The current implementation
+   * uses a hidden property on the object to store the identity hash.
+   *
+   * The return value will never be 0. Also, it is not guaranteed to be
+   * unique.
+   */
+  int GetIdentityHash();
+
+  /**
+   * Clone this object with a fast but shallow copy.  Values will point
+   * to the same values as the original object.
+   */
+  // TODO(dcarney): take an isolate and optionally bail out?
+  Local<Object> Clone();
+
+  /**
+   * Returns the context in which the object was created.
+   */
+  Local<Context> CreationContext();
+
+  /** Same as above, but works for Persistents */
+  V8_INLINE static Local<Context> CreationContext(
+      const PersistentBase<Object>& object) {
+    return object.val_->CreationContext();
+  }
+
+  /**
+   * Checks whether a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * When an Object is callable this method returns true.
+   */
+  bool IsCallable();
+
+  /**
+   * True if this object is a constructor.
+   */
+  bool IsConstructor();
+
+  /**
+   * Call an Object as a function if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsFunction(Local<Value> recv, int argc,
+                                            Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsFunction(Local<Context> context,
+                                                         Local<Value> recv,
+                                                         int argc,
+                                                         Local<Value> argv[]);
+
+  /**
+   * Call an Object as a constructor if a callback is set by the
+   * ObjectTemplate::SetCallAsFunctionHandler method.
+   * Note: This method behaves like the Function::NewInstance method.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Value> CallAsConstructor(int argc, Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> CallAsConstructor(
+      Local<Context> context, int argc, Local<Value> argv[]);
+
+  /**
+   * Return the isolate to which the Object belongs to.
+   */
+  V8_DEPRECATE_SOON("Keep track of isolate correctly", Isolate* GetIsolate());
+
+  static Local<Object> New(Isolate* isolate);
+
+  V8_INLINE static Object* Cast(Value* obj);
+
+ private:
+  Object();
+  static void CheckCast(Value* obj);
+  Local<Value> SlowGetInternalField(int index);
+  void* SlowGetAlignedPointerFromInternalField(int index);
+};
+
+
+/**
+ * An instance of the built-in array constructor (ECMA-262, 15.4.2).
+ */
+class V8_EXPORT Array : public Object {
+ public:
+  uint32_t Length() const;
+
+  /**
+   * Clones an element at index |index|.  Returns an empty
+   * handle if cloning fails (for any reason).
+   */
+  V8_DEPRECATED("Cloning is not supported.",
+                Local<Object> CloneElementAt(uint32_t index));
+  V8_DEPRECATED("Cloning is not supported.",
+                MaybeLocal<Object> CloneElementAt(Local<Context> context,
+                                                  uint32_t index));
+
+  /**
+   * Creates a JavaScript array with the given length. If the length
+   * is negative the returned array will have length 0.
+   */
+  static Local<Array> New(Isolate* isolate, int length = 0);
+
+  V8_INLINE static Array* Cast(Value* obj);
+ private:
+  Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Map constructor (ECMA-262, 6th Edition, 23.1.1).
+ */
+class V8_EXPORT Map : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
+                                              Local<Value> key);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Map> Set(Local<Context> context,
+                                            Local<Value> key,
+                                            Local<Value> value);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of length Size() * 2, where index N is the Nth key and
+   * index N + 1 is the Nth value.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Map.
+   */
+  static Local<Map> New(Isolate* isolate);
+
+  V8_INLINE static Map* Cast(Value* obj);
+
+ private:
+  Map();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Set constructor (ECMA-262, 6th Edition, 23.2.1).
+ */
+class V8_EXPORT Set : public Object {
+ public:
+  size_t Size() const;
+  void Clear();
+  V8_WARN_UNUSED_RESULT MaybeLocal<Set> Add(Local<Context> context,
+                                            Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Has(Local<Context> context,
+                                        Local<Value> key);
+  V8_WARN_UNUSED_RESULT Maybe<bool> Delete(Local<Context> context,
+                                           Local<Value> key);
+
+  /**
+   * Returns an array of the keys in this Set.
+   */
+  Local<Array> AsArray() const;
+
+  /**
+   * Creates a new empty Set.
+   */
+  static Local<Set> New(Isolate* isolate);
+
+  V8_INLINE static Set* Cast(Value* obj);
+
+ private:
+  Set();
+  static void CheckCast(Value* obj);
+};
+
+
+template<typename T>
+class ReturnValue {
+ public:
+  template <class S> V8_INLINE ReturnValue(const ReturnValue<S>& that)
+      : value_(that.value_) {
+    TYPE_CHECK(T, S);
+  }
+  // Local setters
+  template <typename S>
+  V8_INLINE V8_DEPRECATE_SOON("Use Global<> instead",
+                              void Set(const Persistent<S>& handle));
+  template <typename S>
+  V8_INLINE void Set(const Global<S>& handle);
+  template <typename S>
+  V8_INLINE void Set(const Local<S> handle);
+  // Fast primitive setters
+  V8_INLINE void Set(bool value);
+  V8_INLINE void Set(double i);
+  V8_INLINE void Set(int32_t i);
+  V8_INLINE void Set(uint32_t i);
+  // Fast JS primitive setters
+  V8_INLINE void SetNull();
+  V8_INLINE void SetUndefined();
+  V8_INLINE void SetEmptyString();
+  // Convenience getter for Isolate
+  V8_INLINE Isolate* GetIsolate() const;
+
+  // Pointer setter: Uncompilable to prevent inadvertent misuse.
+  template <typename S>
+  V8_INLINE void Set(S* whatever);
+
+  // Getter. Creates a new Local<> so it comes with a certain performance
+  // hit. If the ReturnValue was not yet set, this will return the undefined
+  // value.
+  V8_INLINE Local<Value> Get() const;
+
+ private:
+  template<class F> friend class ReturnValue;
+  template<class F> friend class FunctionCallbackInfo;
+  template<class F> friend class PropertyCallbackInfo;
+  template <class F, class G, class H>
+  friend class PersistentValueMapBase;
+  V8_INLINE void SetInternal(internal::Object* value) { *value_ = value; }
+  V8_INLINE internal::Object* GetDefaultValue();
+  V8_INLINE explicit ReturnValue(internal::Object** slot);
+  internal::Object** value_;
+};
+
+
+/**
+ * The argument information given to function call callbacks.  This
+ * class provides access to information about the context of the call,
+ * including the receiver, the number and values of arguments, and
+ * the holder of the function.
+ */
+template<typename T>
+class FunctionCallbackInfo {
+ public:
+  /** The number of available arguments. */
+  V8_INLINE int Length() const;
+  /** Accessor for the available arguments. */
+  V8_INLINE Local<Value> operator[](int i) const;
+  V8_INLINE V8_DEPRECATED("Use Data() to explicitly pass Callee instead",
+                          Local<Function> Callee() const);
+  /** Returns the receiver. This corresponds to the "this" value. */
+  V8_INLINE Local<Object> This() const;
+  /**
+   * If the callback was created without a Signature, this is the same
+   * value as This(). If there is a signature, and the signature didn't match
+   * This() but one of its hidden prototypes, this will be the respective
+   * hidden prototype.
+   *
+   * Note that this is not the prototype of This() on which the accessor
+   * referencing this callback was found (which in V8 internally is often
+   * referred to as holder [sic]).
+   */
+  V8_INLINE Local<Object> Holder() const;
+  /** For construct calls, this returns the "new.target" value. */
+  V8_INLINE Local<Value> NewTarget() const;
+  /** Indicates whether this is a regular call or a construct call. */
+  V8_INLINE bool IsConstructCall() const;
+  /** The data argument specified when creating the callback. */
+  V8_INLINE Local<Value> Data() const;
+  /** The current Isolate. */
+  V8_INLINE Isolate* GetIsolate() const;
+  /** The ReturnValue for the call. */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 8;
+
+ protected:
+  friend class internal::FunctionCallbackArguments;
+  friend class internal::CustomArguments<FunctionCallbackInfo>;
+  friend class debug::ConsoleCallArguments;
+  static const int kHolderIndex = 0;
+  static const int kIsolateIndex = 1;
+  static const int kReturnValueDefaultValueIndex = 2;
+  static const int kReturnValueIndex = 3;
+  static const int kDataIndex = 4;
+  static const int kCalleeIndex = 5;
+  static const int kContextSaveIndex = 6;
+  static const int kNewTargetIndex = 7;
+
+  V8_INLINE FunctionCallbackInfo(internal::Object** implicit_args,
+                                 internal::Object** values, int length);
+  internal::Object** implicit_args_;
+  internal::Object** values_;
+  int length_;
+};
+
+
+/**
+ * The information passed to a property callback about the context
+ * of the property access.
+ */
+template<typename T>
+class PropertyCallbackInfo {
+ public:
+  /**
+   * \return The isolate of the property access.
+   */
+  V8_INLINE Isolate* GetIsolate() const;
+
+  /**
+   * \return The data set in the configuration, i.e., in
+   * `NamedPropertyHandlerConfiguration` or
+   * `IndexedPropertyHandlerConfiguration.`
+   */
+  V8_INLINE Local<Value> Data() const;
+
+  /**
+   * \return The receiver. In many cases, this is the object on which the
+   * property access was intercepted. When using
+   * `Reflect.get`, `Function.prototype.call`, or similar functions, it is the
+   * object passed in as receiver or thisArg.
+   *
+   * \code
+   *  void GetterCallback(Local<Name> name,
+   *                      const v8::PropertyCallbackInfo<v8::Value>& info) {
+   *     auto context = info.GetIsolate()->GetCurrentContext();
+   *
+   *     v8::Local<v8::Value> a_this =
+   *         info.This()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *     v8::Local<v8::Value> a_holder =
+   *         info.Holder()
+   *             ->GetRealNamedProperty(context, v8_str("a"))
+   *             .ToLocalChecked();
+   *
+   *    CHECK(v8_str("r")->Equals(context, a_this).FromJust());
+   *    CHECK(v8_str("obj")->Equals(context, a_holder).FromJust());
+   *
+   *    info.GetReturnValue().Set(name);
+   *  }
+   *
+   *  v8::Local<v8::FunctionTemplate> templ =
+   *  v8::FunctionTemplate::New(isolate);
+   *  templ->InstanceTemplate()->SetHandler(
+   *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+   *  LocalContext env;
+   *  env->Global()
+   *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+   *                                           .ToLocalChecked()
+   *                                           ->NewInstance(env.local())
+   *                                           .ToLocalChecked())
+   *      .FromJust();
+   *
+   *  CompileRun("obj.a = 'obj'; var r = {a: 'r'}; Reflect.get(obj, 'x', r)");
+   * \endcode
+   */
+  V8_INLINE Local<Object> This() const;
+
+  /**
+   * \return The object in the prototype chain of the receiver that has the
+   * interceptor. Suppose you have `x` and its prototype is `y`, and `y`
+   * has an interceptor. Then `info.This()` is `x` and `info.Holder()` is `y`.
+   * The Holder() could be a hidden object (the global object, rather
+   * than the global proxy).
+   *
+   * \note For security reasons, do not pass the object back into the runtime.
+   */
+  V8_INLINE Local<Object> Holder() const;
+
+  /**
+   * \return The return value of the callback.
+   * Can be changed by calling Set().
+   * \code
+   * info.GetReturnValue().Set(...)
+   * \endcode
+   *
+   */
+  V8_INLINE ReturnValue<T> GetReturnValue() const;
+
+  /**
+   * \return True if the intercepted function should throw if an error occurs.
+   * Usually, `true` corresponds to `'use strict'`.
+   *
+   * \note Always `false` when intercepting `Reflect.set()`
+   * independent of the language mode.
+   */
+  V8_INLINE bool ShouldThrowOnError() const;
+
+  // This shouldn't be public, but the arm compiler needs it.
+  static const int kArgsLength = 7;
+
+ protected:
+  friend class MacroAssembler;
+  friend class internal::PropertyCallbackArguments;
+  friend class internal::CustomArguments<PropertyCallbackInfo>;
+  static const int kShouldThrowOnErrorIndex = 0;
+  static const int kHolderIndex = 1;
+  static const int kIsolateIndex = 2;
+  static const int kReturnValueDefaultValueIndex = 3;
+  static const int kReturnValueIndex = 4;
+  static const int kDataIndex = 5;
+  static const int kThisIndex = 6;
+
+  V8_INLINE PropertyCallbackInfo(internal::Object** args) : args_(args) {}
+  internal::Object** args_;
+};
+
+
+typedef void (*FunctionCallback)(const FunctionCallbackInfo<Value>& info);
+
+enum class ConstructorBehavior { kThrow, kAllow };
+
+/**
+ * A JavaScript function object (ECMA-262, 15.3).
+ */
+class V8_EXPORT Function : public Object {
+ public:
+  /**
+   * Create a function in the current execution context
+   * for a given FunctionCallback.
+   */
+  static MaybeLocal<Function> New(
+      Local<Context> context, FunctionCallback callback,
+      Local<Value> data = Local<Value>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<Function> New(Isolate* isolate, FunctionCallback callback,
+                          Local<Value> data = Local<Value>(), int length = 0));
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Object> NewInstance(int argc, Local<Value> argv[]) const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context, int argc, Local<Value> argv[]) const;
+
+  V8_DEPRECATED("Use maybe version", Local<Object> NewInstance() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(
+      Local<Context> context) const {
+    return NewInstance(context, 0, nullptr);
+  }
+
+  V8_DEPRECATE_SOON("Use maybe version",
+                    Local<Value> Call(Local<Value> recv, int argc,
+                                      Local<Value> argv[]));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> Call(Local<Context> context,
+                                               Local<Value> recv, int argc,
+                                               Local<Value> argv[]);
+
+  void SetName(Local<String> name);
+  Local<Value> GetName() const;
+
+  /**
+   * Name inferred from variable or property assignment of this function.
+   * Used to facilitate debugging and profiling of JavaScript code written
+   * in an OO style, where many functions are anonymous but are assigned
+   * to object properties.
+   */
+  Local<Value> GetInferredName() const;
+
+  /**
+   * displayName if it is set, otherwise name if it is configured, otherwise
+   * function name, otherwise inferred name.
+   */
+  Local<Value> GetDebugName() const;
+
+  /**
+   * User-defined name assigned to the "displayName" property of this function.
+   * Used to facilitate debugging and profiling of JavaScript code.
+   */
+  Local<Value> GetDisplayName() const;
+
+  /**
+   * Returns zero based line number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptLineNumber() const;
+  /**
+   * Returns zero based column number of function body and
+   * kLineOffsetNotFound if no information available.
+   */
+  int GetScriptColumnNumber() const;
+
+  /**
+   * Tells whether this function is builtin.
+   */
+  V8_DEPRECATED("this should no longer be used.", bool IsBuiltin() const);
+
+  /**
+   * Returns scriptId.
+   */
+  int ScriptId() const;
+
+  /**
+   * Returns the original function if this function is bound, else returns
+   * v8::Undefined.
+   */
+  Local<Value> GetBoundFunction() const;
+
+  ScriptOrigin GetScriptOrigin() const;
+  V8_INLINE static Function* Cast(Value* obj);
+  static const int kLineOffsetNotFound;
+
+ private:
+  Function();
+  static void CheckCast(Value* obj);
+};
+
+#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
+#endif
+
+/**
+ * An instance of the built-in Promise constructor (ES6 draft).
+ */
+class V8_EXPORT Promise : public Object {
+ public:
+  /**
+   * State of the promise. Each value corresponds to one of the possible values
+   * of the [[PromiseState]] field.
+   */
+  enum PromiseState { kPending, kFulfilled, kRejected };
+
+  class V8_EXPORT Resolver : public Object {
+   public:
+    /**
+     * Create a new resolver, along with an associated promise in pending state.
+     */
+    static V8_DEPRECATE_SOON("Use maybe version",
+                             Local<Resolver> New(Isolate* isolate));
+    static V8_WARN_UNUSED_RESULT MaybeLocal<Resolver> New(
+        Local<Context> context);
+
+    /**
+     * Extract the associated promise.
+     */
+    Local<Promise> GetPromise();
+
+    /**
+     * Resolve/reject the associated promise with a given value.
+     * Ignored if the promise is no longer pending.
+     */
+    V8_DEPRECATE_SOON("Use maybe version", void Resolve(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Resolve(Local<Context> context,
+                                              Local<Value> value);
+
+    V8_DEPRECATE_SOON("Use maybe version", void Reject(Local<Value> value));
+    V8_WARN_UNUSED_RESULT Maybe<bool> Reject(Local<Context> context,
+                                             Local<Value> value);
+
+    V8_INLINE static Resolver* Cast(Value* obj);
+
+   private:
+    Resolver();
+    static void CheckCast(Value* obj);
+  };
+
+  /**
+   * Register a resolution/rejection handler with a promise.
+   * The handler is given the respective resolution/rejection value as
+   * an argument. If the promise is already resolved/rejected, the handler is
+   * invoked at the end of turn.
+   */
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Catch(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Catch(Local<Context> context,
+                                                  Local<Function> handler);
+
+  V8_DEPRECATED("Use maybe version",
+                Local<Promise> Then(Local<Function> handler));
+  V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
+                                                 Local<Function> handler);
+
+  /**
+   * Returns true if the promise has at least one derived promise, and
+   * therefore resolve/reject handlers (including default handler).
+   */
+  bool HasHandler();
+
+  /**
+   * Returns the content of the [[PromiseResult]] field. The Promise must not
+   * be pending.
+   */
+  Local<Value> Result();
+
+  /**
+   * Returns the value of the [[PromiseState]] field.
+   */
+  PromiseState State();
+
+  V8_INLINE static Promise* Cast(Value* obj);
+
+  static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
+
+ private:
+  Promise();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of a Property Descriptor, see Ecma-262 6.2.4.
+ *
+ * Properties in a descriptor are present or absent. If you do not set
+ * `enumerable`, `configurable`, and `writable`, they are absent. If `value`,
+ * `get`, or `set` are absent, but you must specify them in the constructor, use
+ * empty handles.
+ *
+ * Accessors `get` and `set` must be callable or undefined if they are present.
+ *
+ * \note Only query properties if they are present, i.e., call `x()` only if
+ * `has_x()` returns true.
+ *
+ * \code
+ * // var desc = {writable: false}
+ * v8::PropertyDescriptor d(Local<Value>()), false);
+ * d.value(); // error, value not set
+ * if (d.has_writable()) {
+ *   d.writable(); // false
+ * }
+ *
+ * // var desc = {value: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate));
+ *
+ * // var desc = {get: undefined}
+ * v8::PropertyDescriptor d(v8::Undefined(isolate), Local<Value>()));
+ * \endcode
+ */
+class V8_EXPORT PropertyDescriptor {
+ public:
+  // GenericDescriptor
+  PropertyDescriptor();
+
+  // DataDescriptor
+  PropertyDescriptor(Local<Value> value);
+
+  // DataDescriptor with writable property
+  PropertyDescriptor(Local<Value> value, bool writable);
+
+  // AccessorDescriptor
+  PropertyDescriptor(Local<Value> get, Local<Value> set);
+
+  ~PropertyDescriptor();
+
+  Local<Value> value() const;
+  bool has_value() const;
+
+  Local<Value> get() const;
+  bool has_get() const;
+  Local<Value> set() const;
+  bool has_set() const;
+
+  void set_enumerable(bool enumerable);
+  bool enumerable() const;
+  bool has_enumerable() const;
+
+  void set_configurable(bool configurable);
+  bool configurable() const;
+  bool has_configurable() const;
+
+  bool writable() const;
+  bool has_writable() const;
+
+  struct PrivateData;
+  PrivateData* get_private() const { return private_; }
+
+  PropertyDescriptor(const PropertyDescriptor&) = delete;
+  void operator=(const PropertyDescriptor&) = delete;
+
+ private:
+  PrivateData* private_;
+};
+
+/**
+ * An instance of the built-in Proxy constructor (ECMA-262, 6th Edition,
+ * 26.2.1).
+ */
+class V8_EXPORT Proxy : public Object {
+ public:
+  Local<Object> GetTarget();
+  Local<Value> GetHandler();
+  bool IsRevoked();
+  void Revoke();
+
+  /**
+   * Creates a new Proxy for the target object.
+   */
+  static MaybeLocal<Proxy> New(Local<Context> context,
+                               Local<Object> local_target,
+                               Local<Object> local_handler);
+
+  V8_INLINE static Proxy* Cast(Value* obj);
+
+ private:
+  Proxy();
+  static void CheckCast(Value* obj);
+};
+
+// TODO(mtrofin): rename WasmCompiledModule to WasmModuleObject, for
+// consistency with internal APIs.
+class V8_EXPORT WasmCompiledModule : public Object {
+ public:
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> SerializedModule;
+  // A buffer that is owned by the caller.
+  typedef std::pair<const uint8_t*, size_t> CallerOwnedBuffer;
+
+  // An opaque, native heap object for transferring wasm modules. It
+  // supports move semantics, and does not support copy semantics.
+  class TransferrableModule final {
+   public:
+    TransferrableModule(TransferrableModule&& src) = default;
+    TransferrableModule(const TransferrableModule& src) = delete;
+
+    TransferrableModule& operator=(TransferrableModule&& src) = default;
+    TransferrableModule& operator=(const TransferrableModule& src) = delete;
+
+   private:
+    typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> OwnedBuffer;
+    friend class WasmCompiledModule;
+    TransferrableModule(OwnedBuffer&& code, OwnedBuffer&& bytes)
+        : compiled_code(std::move(code)), wire_bytes(std::move(bytes)) {}
+
+    OwnedBuffer compiled_code = {nullptr, 0};
+    OwnedBuffer wire_bytes = {nullptr, 0};
+  };
+
+  // Get an in-memory, non-persistable, and context-independent (meaning,
+  // suitable for transfer to another Isolate and Context) representation
+  // of this wasm compiled module.
+  TransferrableModule GetTransferrableModule();
+
+  // Efficiently re-create a WasmCompiledModule, without recompiling, from
+  // a TransferrableModule.
+  static MaybeLocal<WasmCompiledModule> FromTransferrableModule(
+      Isolate* isolate, const TransferrableModule&);
+
+  // Get the wasm-encoded bytes that were used to compile this module.
+  Local<String> GetWasmWireBytes();
+
+  // Serialize the compiled module. The serialized data does not include the
+  // uncompiled bytes.
+  SerializedModule Serialize();
+
+  // If possible, deserialize the module, otherwise compile it from the provided
+  // uncompiled bytes.
+  static MaybeLocal<WasmCompiledModule> DeserializeOrCompile(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  V8_INLINE static WasmCompiledModule* Cast(Value* obj);
+
+ private:
+  // TODO(ahaas): please remove the friend once streamed compilation is
+  // implemented
+  friend class WasmModuleObjectBuilder;
+
+  static MaybeLocal<WasmCompiledModule> Deserialize(
+      Isolate* isolate, const CallerOwnedBuffer& serialized_module,
+      const CallerOwnedBuffer& wire_bytes);
+  static MaybeLocal<WasmCompiledModule> Compile(Isolate* isolate,
+                                                const uint8_t* start,
+                                                size_t length);
+  static CallerOwnedBuffer AsCallerOwned(
+      const TransferrableModule::OwnedBuffer& buff) {
+    return {buff.first.get(), buff.second};
+  }
+
+  WasmCompiledModule();
+  static void CheckCast(Value* obj);
+};
+
+class V8_EXPORT WasmModuleObjectBuilder final {
+ public:
+  WasmModuleObjectBuilder(Isolate* isolate) : isolate_(isolate) {}
+  // The buffer passed into OnBytesReceived is owned by the caller.
+  void OnBytesReceived(const uint8_t*, size_t size);
+  MaybeLocal<WasmCompiledModule> Finish();
+
+ private:
+  Isolate* isolate_ = nullptr;
+  // TODO(ahaas): We probably need none of this below here once streamed
+  // compilation is implemented.
+  typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> Buffer;
+
+  // Disable copy semantics *in this implementation*. We can choose to
+  // relax this, albeit it's not clear why.
+  WasmModuleObjectBuilder(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder(WasmModuleObjectBuilder&&) = default;
+  WasmModuleObjectBuilder& operator=(const WasmModuleObjectBuilder&) = delete;
+  WasmModuleObjectBuilder& operator=(WasmModuleObjectBuilder&&) = default;
+
+  std::vector<Buffer> received_buffers_;
+  size_t total_size_ = 0;
+};
+
+#ifndef V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+enum class ArrayBufferCreationMode { kInternalized, kExternalized };
+
+
+/**
+ * An instance of the built-in ArrayBuffer constructor (ES6 draft 15.13.5).
+ */
+class V8_EXPORT ArrayBuffer : public Object {
+ public:
+  /**
+   * A thread-safe allocator that V8 uses to allocate |ArrayBuffer|'s memory.
+   * The allocator is a global V8 setting. It has to be set via
+   * Isolate::CreateParams.
+   *
+   * Memory allocated through this allocator by V8 is accounted for as external
+   * memory by V8. Note that V8 keeps track of the memory for all internalized
+   * |ArrayBuffer|s. Responsibility for tracking external memory (using
+   * Isolate::AdjustAmountOfExternalAllocatedMemory) is handed over to the
+   * embedder upon externalization and taken over upon internalization (creating
+   * an internalized buffer from an existing buffer).
+   *
+   * Note that it is unsafe to call back into V8 from any of the allocator
+   * functions.
+   */
+  class V8_EXPORT Allocator { // NOLINT
+   public:
+    virtual ~Allocator() {}
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory should be initialized to zeroes.
+     */
+    virtual void* Allocate(size_t length) = 0;
+
+    /**
+     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Memory does not have to be initialized.
+     */
+    virtual void* AllocateUninitialized(size_t length) = 0;
+
+    /**
+     * Reserved |length| bytes, but do not commit the memory. Must call
+     * |SetProtection| to make memory accessible.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void* Reserve(size_t length);
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate|.
+     */
+    virtual void Free(void* data, size_t length) = 0;
+
+    enum class AllocationMode { kNormal, kReservation };
+
+    /**
+     * Free the memory block of size |length|, pointed to by |data|.
+     * That memory is guaranteed to be previously allocated by |Allocate| or
+     * |Reserve|, depending on |mode|.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void Free(void* data, size_t length, AllocationMode mode);
+
+    enum class Protection { kNoAccess, kReadWrite };
+
+    /**
+     * Change the protection on a region of memory.
+     *
+     * On platforms that make a distinction between reserving and committing
+     * memory, changing the protection to kReadWrite must also ensure the memory
+     * is committed.
+     */
+    // TODO(eholk): make this pure virtual once blink implements this.
+    virtual void SetProtection(void* data, size_t length,
+                               Protection protection);
+
+    /**
+     * malloc/free based convenience allocator.
+     *
+     * Caller takes ownership, i.e. the returned object needs to be freed using
+     * |delete allocator| once it is no longer in use.
+     */
+    static Allocator* NewDefaultAllocator();
+  };
+
+  /**
+   * The contents of an |ArrayBuffer|. Externalization of |ArrayBuffer|
+   * returns an instance of this class, populated, with a pointer to data
+   * and byte length.
+   *
+   * The Data pointer of ArrayBuffer::Contents is always allocated with
+   * Allocator::Allocate that is set via Isolate::CreateParams.
+   */
+  class V8_EXPORT Contents { // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class ArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new ArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created ArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<ArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new ArrayBuffer over an existing memory block.
+   * The created array buffer is by default immediately in externalized state.
+   * In externalized state, the memory block will not be reclaimed when a
+   * created ArrayBuffer is garbage-collected.
+   * In internalized state, the memory block will be released using
+   * |Allocator::Free| once all ArrayBuffers referencing it are collected by
+   * the garbage collector.
+   */
+  static Local<ArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if ArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Returns true if this ArrayBuffer may be neutered.
+   */
+  bool IsNeuterable() const;
+
+  /**
+   * Neuters this ArrayBuffer and all its views (typed arrays).
+   * Neutering sets the byte length of the buffer and all typed arrays to zero,
+   * preventing JavaScript from ever accessing underlying backing store.
+   * ArrayBuffer should have been externalized and must be neuterable.
+   */
+  void Neuter();
+
+  /**
+   * Make this ArrayBuffer external. The pointer to underlying memory block
+   * and byte length are returned as |Contents| structure. After ArrayBuffer
+   * had been externalized, it does no longer own the memory block. The caller
+   * should take steps to free memory when it is no longer needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * that has been set via Isolate::CreateParams.
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer gets garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|.
+   */
+  Contents GetContents();
+
+  V8_INLINE static ArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+#ifndef V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT
+// The number of required internal fields can be defined by embedder.
+#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
+#endif
+
+
+/**
+ * A base class for an instance of one of "views" over ArrayBuffer,
+ * including TypedArrays and DataView (ES6 draft 15.13).
+ */
+class V8_EXPORT ArrayBufferView : public Object {
+ public:
+  /**
+   * Returns underlying ArrayBuffer.
+   */
+  Local<ArrayBuffer> Buffer();
+  /**
+   * Byte offset in |Buffer|.
+   */
+  size_t ByteOffset();
+  /**
+   * Size of a view in bytes.
+   */
+  size_t ByteLength();
+
+  /**
+   * Copy the contents of the ArrayBufferView's buffer to an embedder defined
+   * memory without additional overhead that calling ArrayBufferView::Buffer
+   * might incur.
+   *
+   * Will write at most min(|byte_length|, ByteLength) bytes starting at
+   * ByteOffset of the underlying buffer to the memory starting at |dest|.
+   * Returns the number of bytes actually written.
+   */
+  size_t CopyContents(void* dest, size_t byte_length);
+
+  /**
+   * Returns true if ArrayBufferView's backing ArrayBuffer has already been
+   * allocated.
+   */
+  bool HasBuffer() const;
+
+  V8_INLINE static ArrayBufferView* Cast(Value* obj);
+
+  static const int kInternalFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+  static const int kEmbedderFieldCount =
+      V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT;
+
+ private:
+  ArrayBufferView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A base class for an instance of TypedArray series of constructors
+ * (ES6 draft 15.13.6).
+ */
+class V8_EXPORT TypedArray : public ArrayBufferView {
+ public:
+  /**
+   * Number of elements in this typed array
+   * (e.g. for Int16Array, |ByteLength|/2).
+   */
+  size_t Length();
+
+  V8_INLINE static TypedArray* Cast(Value* obj);
+
+ private:
+  TypedArray();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8Array : public TypedArray {
+ public:
+  static Local<Uint8Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Uint8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Uint8Array* Cast(Value* obj);
+
+ private:
+  Uint8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint8ClampedArray constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint8ClampedArray : public TypedArray {
+ public:
+  static Local<Uint8ClampedArray> New(Local<ArrayBuffer> array_buffer,
+                                      size_t byte_offset, size_t length);
+  static Local<Uint8ClampedArray> New(
+      Local<SharedArrayBuffer> shared_array_buffer, size_t byte_offset,
+      size_t length);
+  V8_INLINE static Uint8ClampedArray* Cast(Value* obj);
+
+ private:
+  Uint8ClampedArray();
+  static void CheckCast(Value* obj);
+};
+
+/**
+ * An instance of Int8Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int8Array : public TypedArray {
+ public:
+  static Local<Int8Array> New(Local<ArrayBuffer> array_buffer,
+                              size_t byte_offset, size_t length);
+  static Local<Int8Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                              size_t byte_offset, size_t length);
+  V8_INLINE static Int8Array* Cast(Value* obj);
+
+ private:
+  Int8Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint16Array : public TypedArray {
+ public:
+  static Local<Uint16Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint16Array* Cast(Value* obj);
+
+ private:
+  Uint16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int16Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int16Array : public TypedArray {
+ public:
+  static Local<Int16Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int16Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int16Array* Cast(Value* obj);
+
+ private:
+  Int16Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Uint32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Uint32Array : public TypedArray {
+ public:
+  static Local<Uint32Array> New(Local<ArrayBuffer> array_buffer,
+                                size_t byte_offset, size_t length);
+  static Local<Uint32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                size_t byte_offset, size_t length);
+  V8_INLINE static Uint32Array* Cast(Value* obj);
+
+ private:
+  Uint32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Int32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Int32Array : public TypedArray {
+ public:
+  static Local<Int32Array> New(Local<ArrayBuffer> array_buffer,
+                               size_t byte_offset, size_t length);
+  static Local<Int32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                               size_t byte_offset, size_t length);
+  V8_INLINE static Int32Array* Cast(Value* obj);
+
+ private:
+  Int32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float32Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float32Array : public TypedArray {
+ public:
+  static Local<Float32Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float32Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float32Array* Cast(Value* obj);
+
+ private:
+  Float32Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of Float64Array constructor (ES6 draft 15.13.6).
+ */
+class V8_EXPORT Float64Array : public TypedArray {
+ public:
+  static Local<Float64Array> New(Local<ArrayBuffer> array_buffer,
+                                 size_t byte_offset, size_t length);
+  static Local<Float64Array> New(Local<SharedArrayBuffer> shared_array_buffer,
+                                 size_t byte_offset, size_t length);
+  V8_INLINE static Float64Array* Cast(Value* obj);
+
+ private:
+  Float64Array();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of DataView constructor (ES6 draft 15.13.7).
+ */
+class V8_EXPORT DataView : public ArrayBufferView {
+ public:
+  static Local<DataView> New(Local<ArrayBuffer> array_buffer,
+                             size_t byte_offset, size_t length);
+  static Local<DataView> New(Local<SharedArrayBuffer> shared_array_buffer,
+                             size_t byte_offset, size_t length);
+  V8_INLINE static DataView* Cast(Value* obj);
+
+ private:
+  DataView();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in SharedArrayBuffer constructor.
+ * This API is experimental and may change significantly.
+ */
+class V8_EXPORT SharedArrayBuffer : public Object {
+ public:
+  /**
+   * The contents of an |SharedArrayBuffer|. Externalization of
+   * |SharedArrayBuffer| returns an instance of this class, populated, with a
+   * pointer to data and byte length.
+   *
+   * The Data pointer of SharedArrayBuffer::Contents is always allocated with
+   * |ArrayBuffer::Allocator::Allocate| by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   * This API is experimental and may change significantly.
+   */
+  class V8_EXPORT Contents {  // NOLINT
+   public:
+    Contents() : data_(NULL), byte_length_(0) {}
+
+    void* Data() const { return data_; }
+    size_t ByteLength() const { return byte_length_; }
+
+   private:
+    void* data_;
+    size_t byte_length_;
+
+    friend class SharedArrayBuffer;
+  };
+
+
+  /**
+   * Data length in bytes.
+   */
+  size_t ByteLength() const;
+
+  /**
+   * Create a new SharedArrayBuffer. Allocate |byte_length| bytes.
+   * Allocated memory will be owned by a created SharedArrayBuffer and
+   * will be deallocated when it is garbage-collected,
+   * unless the object is externalized.
+   */
+  static Local<SharedArrayBuffer> New(Isolate* isolate, size_t byte_length);
+
+  /**
+   * Create a new SharedArrayBuffer over an existing memory block.  The created
+   * array buffer is immediately in externalized state unless otherwise
+   * specified. The memory block will not be reclaimed when a created
+   * SharedArrayBuffer is garbage-collected.
+   */
+  static Local<SharedArrayBuffer> New(
+      Isolate* isolate, void* data, size_t byte_length,
+      ArrayBufferCreationMode mode = ArrayBufferCreationMode::kExternalized);
+
+  /**
+   * Returns true if SharedArrayBuffer is externalized, that is, does not
+   * own its memory block.
+   */
+  bool IsExternal() const;
+
+  /**
+   * Make this SharedArrayBuffer external. The pointer to underlying memory
+   * block and byte length are returned as |Contents| structure. After
+   * SharedArrayBuffer had been externalized, it does no longer own the memory
+   * block. The caller should take steps to free memory when it is no longer
+   * needed.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   *
+   */
+  Contents Externalize();
+
+  /**
+   * Get a pointer to the ArrayBuffer's underlying memory block without
+   * externalizing it. If the ArrayBuffer is not externalized, this pointer
+   * will become invalid as soon as the ArrayBuffer became garbage collected.
+   *
+   * The embedder should make sure to hold a strong reference to the
+   * ArrayBuffer while accessing this pointer.
+   *
+   * The memory block is guaranteed to be allocated with |Allocator::Allocate|
+   * by the allocator specified in
+   * v8::Isolate::CreateParams::array_buffer_allocator.
+   */
+  Contents GetContents();
+
+  V8_INLINE static SharedArrayBuffer* Cast(Value* obj);
+
+  static const int kInternalFieldCount = V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT;
+
+ private:
+  SharedArrayBuffer();
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in Date constructor (ECMA-262, 15.9).
+ */
+class V8_EXPORT Date : public Object {
+ public:
+  static V8_DEPRECATE_SOON("Use maybe version.",
+                           Local<Value> New(Isolate* isolate, double time));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Value> New(Local<Context> context,
+                                                     double time);
+
+  /**
+   * A specialization of Value::NumberValue that is more efficient
+   * because we know the structure of this object.
+   */
+  double ValueOf() const;
+
+  V8_INLINE static Date* Cast(Value* obj);
+
+  /**
+   * Notification that the embedder has changed the time zone,
+   * daylight savings time, or other date / time configuration
+   * parameters.  V8 keeps a cache of various values used for
+   * date / time computation.  This notification will reset
+   * those cached values for the current context so that date /
+   * time configuration changes would be reflected in the Date
+   * object.
+   *
+   * This API should not be called more than needed as it will
+   * negatively impact the performance of date operations.
+   */
+  static void DateTimeConfigurationChangeNotification(Isolate* isolate);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Number object (ECMA-262, 4.3.21).
+ */
+class V8_EXPORT NumberObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, double value);
+
+  double ValueOf() const;
+
+  V8_INLINE static NumberObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Boolean object (ECMA-262, 4.3.15).
+ */
+class V8_EXPORT BooleanObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, bool value);
+  V8_DEPRECATED("Pass an isolate", static Local<Value> New(bool value));
+
+  bool ValueOf() const;
+
+  V8_INLINE static BooleanObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A String object (ECMA-262, 4.3.18).
+ */
+class V8_EXPORT StringObject : public Object {
+ public:
+  static Local<Value> New(Local<String> value);
+
+  Local<String> ValueOf() const;
+
+  V8_INLINE static StringObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A Symbol object (ECMA-262 edition 6).
+ */
+class V8_EXPORT SymbolObject : public Object {
+ public:
+  static Local<Value> New(Isolate* isolate, Local<Symbol> value);
+
+  Local<Symbol> ValueOf() const;
+
+  V8_INLINE static SymbolObject* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * An instance of the built-in RegExp constructor (ECMA-262, 15.10).
+ */
+class V8_EXPORT RegExp : public Object {
+ public:
+  /**
+   * Regular expression flag bits. They can be or'ed to enable a set
+   * of flags.
+   */
+  enum Flags {
+    kNone = 0,
+    kGlobal = 1 << 0,
+    kIgnoreCase = 1 << 1,
+    kMultiline = 1 << 2,
+    kSticky = 1 << 3,
+    kUnicode = 1 << 4,
+    kDotAll = 1 << 5,
+  };
+
+  /**
+   * Creates a regular expression from the given pattern string and
+   * the flags bit field. May throw a JavaScript exception as
+   * described in ECMA-262, 15.10.4.1.
+   *
+   * For example,
+   *   RegExp::New(v8::String::New("foo"),
+   *               static_cast<RegExp::Flags>(kGlobal | kMultiline))
+   * is equivalent to evaluating "/foo/gm".
+   */
+  static V8_DEPRECATE_SOON("Use maybe version",
+                           Local<RegExp> New(Local<String> pattern,
+                                             Flags flags));
+  static V8_WARN_UNUSED_RESULT MaybeLocal<RegExp> New(Local<Context> context,
+                                                      Local<String> pattern,
+                                                      Flags flags);
+
+  /**
+   * Returns the value of the source property: a string representing
+   * the regular expression.
+   */
+  Local<String> GetSource() const;
+
+  /**
+   * Returns the flags bit field.
+   */
+  Flags GetFlags() const;
+
+  V8_INLINE static RegExp* Cast(Value* obj);
+
+ private:
+  static void CheckCast(Value* obj);
+};
+
+
+/**
+ * A JavaScript value that wraps a C++ void*. This type of value is mainly used
+ * to associate C++ data structures with JavaScript objects.
+ */
+class V8_EXPORT External : public Value {
+ public:
+  static Local<External> New(Isolate* isolate, void* value);
+  V8_INLINE static External* Cast(Value* obj);
+  void* Value() const;
+ private:
+  static void CheckCast(v8::Value* obj);
+};
+
+#define V8_INTRINSICS_LIST(F)                    \
+  F(ArrayProto_entries, array_entries_iterator)  \
+  F(ArrayProto_forEach, array_for_each_iterator) \
+  F(ArrayProto_keys, array_keys_iterator)        \
+  F(ArrayProto_values, array_values_iterator)    \
+  F(IteratorPrototype, initial_iterator_prototype)
+
+enum Intrinsic {
+#define V8_DECL_INTRINSIC(name, iname) k##name,
+  V8_INTRINSICS_LIST(V8_DECL_INTRINSIC)
+#undef V8_DECL_INTRINSIC
+};
+
+
+// --- Templates ---
+
+
+/**
+ * The superclass of object and function templates.
+ */
+class V8_EXPORT Template : public Data {
+ public:
+  /**
+   * Adds a property to each instance created by this template.
+   *
+   * The property must be defined either as a primitive value, or a template.
+   */
+  void Set(Local<Name> name, Local<Data> value,
+           PropertyAttribute attributes = None);
+  void SetPrivate(Local<Private> name, Local<Data> value,
+                  PropertyAttribute attributes = None);
+  V8_INLINE void Set(Isolate* isolate, const char* name, Local<Data> value);
+
+  void SetAccessorProperty(
+     Local<Name> name,
+     Local<FunctionTemplate> getter = Local<FunctionTemplate>(),
+     Local<FunctionTemplate> setter = Local<FunctionTemplate>(),
+     PropertyAttribute attribute = None,
+     AccessControl settings = DEFAULT);
+
+  /**
+   * Whenever the property with the given name is accessed on objects
+   * created from this Template the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetNativeDataProperty(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+  void SetNativeDataProperty(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0,
+      // TODO(dcarney): gcc can't handle Local below
+      Local<Value> data = Local<Value>(), PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>(),
+      AccessControl settings = DEFAULT);
+
+  /**
+   * Like SetNativeDataProperty, but V8 will replace the native data property
+   * with a real data property on first access.
+   */
+  void SetLazyDataProperty(Local<Name> name, AccessorNameGetterCallback getter,
+                           Local<Value> data = Local<Value>(),
+                           PropertyAttribute attribute = None);
+
+  /**
+   * During template instantiation, sets the value with the intrinsic property
+   * from the correct context.
+   */
+  void SetIntrinsicDataProperty(Local<Name> name, Intrinsic intrinsic,
+                                PropertyAttribute attribute = None);
+
+ private:
+  Template();
+
+  friend class ObjectTemplate;
+  friend class FunctionTemplate;
+};
+
+
+/**
+ * NamedProperty[Getter|Setter] are used as interceptors on object.
+ * See ObjectTemplate::SetNamedPropertyHandler.
+ */
+typedef void (*NamedPropertyGetterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns the value if the setter intercepts the request.
+ * Otherwise, returns an empty handle.
+ */
+typedef void (*NamedPropertySetterCallback)(
+    Local<String> property,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+
+/**
+ * Returns a non-empty handle if the interceptor intercepts the request.
+ * The result is an integer encoding property attributes (like v8::None,
+ * v8::DontEnum, etc.)
+ */
+typedef void (*NamedPropertyQueryCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Integer>& info);
+
+
+/**
+ * Returns a non-empty handle if the deleter intercepts the request.
+ * The return value is true if the property could be deleted and false
+ * otherwise.
+ */
+typedef void (*NamedPropertyDeleterCallback)(
+    Local<String> property,
+    const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*NamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+
+// TODO(dcarney): Deprecate and remove previous typedefs, and replace
+// GenericNamedPropertyFooCallback with just NamedPropertyFooCallback.
+
+/**
+ * Interceptor for get requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted get request.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict`' mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \code
+ *  void GetterCallback(
+ *    Local<Name> name,
+ *    const v8::PropertyCallbackInfo<v8::Value>& info) {
+ *      info.GetReturnValue().Set(v8_num(42));
+ *  }
+ *
+ *  v8::Local<v8::FunctionTemplate> templ =
+ *      v8::FunctionTemplate::New(isolate);
+ *  templ->InstanceTemplate()->SetHandler(
+ *      v8::NamedPropertyHandlerConfiguration(GetterCallback));
+ *  LocalContext env;
+ *  env->Global()
+ *      ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
+ *                                             .ToLocalChecked()
+ *                                             ->NewInstance(env.local())
+ *                                             .ToLocalChecked())
+ *      .FromJust();
+ *  v8::Local<v8::Value> result = CompileRun("obj.a = 17; obj.a");
+ *  CHECK(v8_num(42)->Equals(env.local(), result).FromJust());
+ * \endcode
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyGetterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for set requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the setter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the setter
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param value The value which the property will have if the request
+ * is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertySetterCallback)(
+    Local<Name> property, Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Intercepts all requests that query the attributes of the
+ * property, e.g., getOwnPropertyDescriptor(), propertyIsEnumerable(), and
+ * defineProperty().
+ *
+ * Use `info.GetReturnValue().Set(value)` to set the property attributes. The
+ * value is an interger encoding a `v8::PropertyAttribute`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note Some functions query the property attributes internally, even though
+ * they do not return the attributes. For example, `hasOwnProperty()` can
+ * trigger this interceptor depending on the state of the object.
+ *
+ * See also
+ * `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyQueryCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * Interceptor for delete requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the deleter successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)` with a boolean `value`. The `value` is
+ * used as the return value of `delete`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If you need to mimic the behavior of `delete`, i.e., throw in strict
+ * mode instead of returning false, use `info.ShouldThrowOnError()` to determine
+ * if you are in strict mode.
+ *
+ * See also `ObjectTemplate::SetHandler.`
+ */
+typedef void (*GenericNamedPropertyDeleterCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Boolean>& info);
+
+
+/**
+ * Returns an array containing the names of the properties the named
+ * property getter intercepts.
+ */
+typedef void (*GenericNamedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * Interceptor for defineProperty requests on an object.
+ *
+ * Use `info.GetReturnValue()` to indicate whether the request was intercepted
+ * or not. If the definer successfully intercepts the request, i.e., if the
+ * request should not be further executed, call
+ * `info.GetReturnValue().Set(value)`. If the definer
+ * did not intercept the request, i.e., if the request should be handled as
+ * if no interceptor is present, do not not call `Set()`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \param desc The property descriptor which is used to define the
+ * property if the request is not intercepted.
+ * \param info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDefinerCallback)(
+    Local<Name> property, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Interceptor for getOwnPropertyDescriptor requests on an object.
+ *
+ * Use `info.GetReturnValue().Set()` to set the return value of the
+ * intercepted request. The return value must be an object that
+ * can be converted to a PropertyDescriptor, e.g., a `v8::value` returned from
+ * `v8::Object::getOwnPropertyDescriptor`.
+ *
+ * \param property The name of the property for which the request was
+ * intercepted.
+ * \info Information about the intercepted request, such as
+ * isolate, receiver, return value, or whether running in `'use strict'` mode.
+ * See `PropertyCallbackInfo`.
+ *
+ * \note If GetOwnPropertyDescriptor is intercepted, it will
+ * always return true, i.e., indicate that the property was found.
+ *
+ * See also `ObjectTemplate::SetHandler`.
+ */
+typedef void (*GenericNamedPropertyDescriptorCallback)(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyGetterCallback`.
+ */
+typedef void (*IndexedPropertyGetterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertySetterCallback`.
+ */
+typedef void (*IndexedPropertySetterCallback)(
+    uint32_t index,
+    Local<Value> value,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyQueryCallback`.
+ */
+typedef void (*IndexedPropertyQueryCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Integer>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDeleterCallback`.
+ */
+typedef void (*IndexedPropertyDeleterCallback)(
+    uint32_t index,
+    const PropertyCallbackInfo<Boolean>& info);
+
+/**
+ * See `v8::GenericNamedPropertyEnumeratorCallback`.
+ */
+typedef void (*IndexedPropertyEnumeratorCallback)(
+    const PropertyCallbackInfo<Array>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDefinerCallback`.
+ */
+typedef void (*IndexedPropertyDefinerCallback)(
+    uint32_t index, const PropertyDescriptor& desc,
+    const PropertyCallbackInfo<Value>& info);
+
+/**
+ * See `v8::GenericNamedPropertyDescriptorCallback`.
+ */
+typedef void (*IndexedPropertyDescriptorCallback)(
+    uint32_t index, const PropertyCallbackInfo<Value>& info);
+
+/**
+ * Access type specification.
+ */
+enum AccessType {
+  ACCESS_GET,
+  ACCESS_SET,
+  ACCESS_HAS,
+  ACCESS_DELETE,
+  ACCESS_KEYS
+};
+
+
+/**
+ * Returns true if the given context should be allowed to access the given
+ * object.
+ */
+typedef bool (*AccessCheckCallback)(Local<Context> accessing_context,
+                                    Local<Object> accessed_object,
+                                    Local<Value> data);
+
+/**
+ * A FunctionTemplate is used to create functions at runtime. There
+ * can only be one function created from a FunctionTemplate in a
+ * context.  The lifetime of the created function is equal to the
+ * lifetime of the context.  So in case the embedder needs to create
+ * temporary functions that can be collected using Scripts is
+ * preferred.
+ *
+ * Any modification of a FunctionTemplate after first instantiation will trigger
+ * a crash.
+ *
+ * A FunctionTemplate can have properties, these properties are added to the
+ * function object when it is created.
+ *
+ * A FunctionTemplate has a corresponding instance template which is
+ * used to create object instances when the function is used as a
+ * constructor. Properties added to the instance template are added to
+ * each object instance.
+ *
+ * A FunctionTemplate can have a prototype template. The prototype template
+ * is used to create the prototype object of the function.
+ *
+ * The following example shows how to use a FunctionTemplate:
+ *
+ * \code
+ *    v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(isolate);
+ *    t->Set(isolate, "func_property", v8::Number::New(isolate, 1));
+ *
+ *    v8::Local<v8::Template> proto_t = t->PrototypeTemplate();
+ *    proto_t->Set(isolate,
+ *                 "proto_method",
+ *                 v8::FunctionTemplate::New(isolate, InvokeCallback));
+ *    proto_t->Set(isolate, "proto_const", v8::Number::New(isolate, 2));
+ *
+ *    v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
+ *    instance_t->SetAccessor(String::NewFromUtf8(isolate, "instance_accessor"),
+ *                            InstanceAccessorCallback);
+ *    instance_t->SetNamedPropertyHandler(PropertyHandlerCallback);
+ *    instance_t->Set(String::NewFromUtf8(isolate, "instance_property"),
+ *                    Number::New(isolate, 3));
+ *
+ *    v8::Local<v8::Function> function = t->GetFunction();
+ *    v8::Local<v8::Object> instance = function->NewInstance();
+ * \endcode
+ *
+ * Let's use "function" as the JS variable name of the function object
+ * and "instance" for the instance object created above.  The function
+ * and the instance will have the following properties:
+ *
+ * \code
+ *   func_property in function == true;
+ *   function.func_property == 1;
+ *
+ *   function.prototype.proto_method() invokes 'InvokeCallback'
+ *   function.prototype.proto_const == 2;
+ *
+ *   instance instanceof function == true;
+ *   instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   instance.instance_property == 3;
+ * \endcode
+ *
+ * A FunctionTemplate can inherit from another one by calling the
+ * FunctionTemplate::Inherit method.  The following graph illustrates
+ * the semantics of inheritance:
+ *
+ * \code
+ *   FunctionTemplate Parent  -> Parent() . prototype -> { }
+ *     ^                                                  ^
+ *     | Inherit(Parent)                                  | .__proto__
+ *     |                                                  |
+ *   FunctionTemplate Child   -> Child()  . prototype -> { }
+ * \endcode
+ *
+ * A FunctionTemplate 'Child' inherits from 'Parent', the prototype
+ * object of the Child() function has __proto__ pointing to the
+ * Parent() function's prototype object. An instance of the Child
+ * function has all properties on Parent's instance templates.
+ *
+ * Let Parent be the FunctionTemplate initialized in the previous
+ * section and create a Child FunctionTemplate by:
+ *
+ * \code
+ *   Local<FunctionTemplate> parent = t;
+ *   Local<FunctionTemplate> child = FunctionTemplate::New();
+ *   child->Inherit(parent);
+ *
+ *   Local<Function> child_function = child->GetFunction();
+ *   Local<Object> child_instance = child_function->NewInstance();
+ * \endcode
+ *
+ * The Child function and Child instance will have the following
+ * properties:
+ *
+ * \code
+ *   child_func.prototype.__proto__ == function.prototype;
+ *   child_instance.instance_accessor calls 'InstanceAccessorCallback'
+ *   child_instance.instance_property == 3;
+ * \endcode
+ */
+class V8_EXPORT FunctionTemplate : public Template {
+ public:
+  /** Creates a function template.*/
+  static Local<FunctionTemplate> New(
+      Isolate* isolate, FunctionCallback callback = 0,
+      Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow);
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<FunctionTemplate> FromSnapshot(Isolate* isolate,
+                                                   size_t index);
+
+  /**
+   * Creates a function template backed/cached by a private property.
+   */
+  static Local<FunctionTemplate> NewWithCache(
+      Isolate* isolate, FunctionCallback callback,
+      Local<Private> cache_property, Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0);
+
+  /** Returns the unique function instance in the current execution context.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Function> GetFunction());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Function> GetFunction(
+      Local<Context> context);
+
+  /**
+   * Similar to Context::NewRemoteContext, this creates an instance that
+   * isn't backed by an actual object.
+   *
+   * The InstanceTemplate of this FunctionTemplate must have access checks with
+   * handlers installed.
+   */
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewRemoteInstance();
+
+  /**
+   * Set the call-handler callback for a FunctionTemplate.  This
+   * callback is called whenever the function created from this
+   * FunctionTemplate is called.
+   */
+  void SetCallHandler(FunctionCallback callback,
+                      Local<Value> data = Local<Value>());
+
+  /** Set the predefined length property for the FunctionTemplate. */
+  void SetLength(int length);
+
+  /** Get the InstanceTemplate. */
+  Local<ObjectTemplate> InstanceTemplate();
+
+  /**
+   * Causes the function template to inherit from a parent function template.
+   * This means the the function's prototype.__proto__ is set to the parent
+   * function's prototype.
+   **/
+  void Inherit(Local<FunctionTemplate> parent);
+
+  /**
+   * A PrototypeTemplate is the template used to create the prototype object
+   * of the function created by this template.
+   */
+  Local<ObjectTemplate> PrototypeTemplate();
+
+  /**
+   * A PrototypeProviderTemplate is another function template whose prototype
+   * property is used for this template. This is mutually exclusive with setting
+   * a prototype template indirectly by calling PrototypeTemplate() or using
+   * Inherit().
+   **/
+  void SetPrototypeProviderTemplate(Local<FunctionTemplate> prototype_provider);
+
+  /**
+   * Set the class name of the FunctionTemplate.  This is used for
+   * printing objects created with the function created from the
+   * FunctionTemplate as its constructor.
+   */
+  void SetClassName(Local<String> name);
+
+
+  /**
+   * When set to true, no access check will be performed on the receiver of a
+   * function call.  Currently defaults to true, but this is subject to change.
+   */
+  void SetAcceptAnyReceiver(bool value);
+
+  /**
+   * Determines whether the __proto__ accessor ignores instances of
+   * the function template.  If instances of the function template are
+   * ignored, __proto__ skips all instances and instead returns the
+   * next object in the prototype chain.
+   *
+   * Call with a value of true to make the __proto__ accessor ignore
+   * instances of the function template.  Call with a value of false
+   * to make the __proto__ accessor not ignore instances of the
+   * function template.  By default, instances of a function template
+   * are not ignored.
+   */
+  void SetHiddenPrototype(bool value);
+
+  /**
+   * Sets the ReadOnly flag in the attributes of the 'prototype' property
+   * of functions created from this FunctionTemplate to true.
+   */
+  void ReadOnlyPrototype();
+
+  /**
+   * Removes the prototype property from functions created from this
+   * FunctionTemplate.
+   */
+  void RemovePrototype();
+
+  /**
+   * Returns true if the given object is an instance of this function
+   * template.
+   */
+  bool HasInstance(Local<Value> object);
+
+ private:
+  FunctionTemplate();
+  friend class Context;
+  friend class ObjectTemplate;
+};
+
+/**
+ * Configuration flags for v8::NamedPropertyHandlerConfiguration or
+ * v8::IndexedPropertyHandlerConfiguration.
+ */
+enum class PropertyHandlerFlags {
+  /**
+   * None.
+   */
+  kNone = 0,
+
+  /**
+   * See ALL_CAN_READ above.
+   */
+  kAllCanRead = 1,
+
+  /** Will not call into interceptor for properties on the receiver or prototype
+   * chain, i.e., only call into interceptor for properties that do not exist.
+   * Currently only valid for named interceptors.
+   */
+  kNonMasking = 1 << 1,
+
+  /**
+   * Will not call into interceptor for symbol lookup.  Only meaningful for
+   * named interceptors.
+   */
+  kOnlyInterceptStrings = 1 << 2,
+};
+
+struct NamedPropertyHandlerConfiguration {
+  NamedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      GenericNamedPropertyGetterCallback getter = 0,
+      GenericNamedPropertySetterCallback setter = 0,
+      GenericNamedPropertyQueryCallback query = 0,
+      GenericNamedPropertyDeleterCallback deleter = 0,
+      GenericNamedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  NamedPropertyHandlerConfiguration(
+      GenericNamedPropertyGetterCallback getter,
+      GenericNamedPropertySetterCallback setter,
+      GenericNamedPropertyDescriptorCallback descriptor,
+      GenericNamedPropertyDeleterCallback deleter,
+      GenericNamedPropertyEnumeratorCallback enumerator,
+      GenericNamedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  GenericNamedPropertyGetterCallback getter;
+  GenericNamedPropertySetterCallback setter;
+  GenericNamedPropertyQueryCallback query;
+  GenericNamedPropertyDeleterCallback deleter;
+  GenericNamedPropertyEnumeratorCallback enumerator;
+  GenericNamedPropertyDefinerCallback definer;
+  GenericNamedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+struct IndexedPropertyHandlerConfiguration {
+  IndexedPropertyHandlerConfiguration(
+      /** Note: getter is required */
+      IndexedPropertyGetterCallback getter = 0,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(query),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(0),
+        descriptor(0),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyHandlerConfiguration(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter,
+      IndexedPropertyDescriptorCallback descriptor,
+      IndexedPropertyDeleterCallback deleter,
+      IndexedPropertyEnumeratorCallback enumerator,
+      IndexedPropertyDefinerCallback definer,
+      Local<Value> data = Local<Value>(),
+      PropertyHandlerFlags flags = PropertyHandlerFlags::kNone)
+      : getter(getter),
+        setter(setter),
+        query(0),
+        deleter(deleter),
+        enumerator(enumerator),
+        definer(definer),
+        descriptor(descriptor),
+        data(data),
+        flags(flags) {}
+
+  IndexedPropertyGetterCallback getter;
+  IndexedPropertySetterCallback setter;
+  IndexedPropertyQueryCallback query;
+  IndexedPropertyDeleterCallback deleter;
+  IndexedPropertyEnumeratorCallback enumerator;
+  IndexedPropertyDefinerCallback definer;
+  IndexedPropertyDescriptorCallback descriptor;
+  Local<Value> data;
+  PropertyHandlerFlags flags;
+};
+
+
+/**
+ * An ObjectTemplate is used to create objects at runtime.
+ *
+ * Properties added to an ObjectTemplate are added to each object
+ * created from the ObjectTemplate.
+ */
+class V8_EXPORT ObjectTemplate : public Template {
+ public:
+  /** Creates an ObjectTemplate. */
+  static Local<ObjectTemplate> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> constructor = Local<FunctionTemplate>());
+  static V8_DEPRECATED("Use isolate version", Local<ObjectTemplate> New());
+
+  /** Get a template included in the snapshot by index. */
+  static MaybeLocal<ObjectTemplate> FromSnapshot(Isolate* isolate,
+                                                 size_t index);
+
+  /** Creates a new instance of this template.*/
+  V8_DEPRECATE_SOON("Use maybe version", Local<Object> NewInstance());
+  V8_WARN_UNUSED_RESULT MaybeLocal<Object> NewInstance(Local<Context> context);
+
+  /**
+   * Sets an accessor on the object template.
+   *
+   * Whenever the property with the given name is accessed on objects
+   * created from this ObjectTemplate the getter and setter callbacks
+   * are called instead of getting and setting the property directly
+   * on the JavaScript object.
+   *
+   * \param name The name of the property for which an accessor is added.
+   * \param getter The callback to invoke when getting the property.
+   * \param setter The callback to invoke when setting the property.
+   * \param data A piece of data that will be passed to the getter and setter
+   *   callbacks whenever they are invoked.
+   * \param settings Access control settings for the accessor. This is a bit
+   *   field consisting of one of more of
+   *   DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
+   *   The default is to not allow cross-context access.
+   *   ALL_CAN_READ means that all cross-context reads are allowed.
+   *   ALL_CAN_WRITE means that all cross-context writes are allowed.
+   *   The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
+   *   cross-context access.
+   * \param attribute The attributes of the property for which an accessor
+   *   is added.
+   * \param signature The signature describes valid receivers for the accessor
+   *   and is used to perform implicit instance checks against them. If the
+   *   receiver is incompatible (i.e. is not an instance of the constructor as
+   *   defined by FunctionTemplate::HasInstance()), an implicit TypeError is
+   *   thrown and no callback is invoked.
+   */
+  void SetAccessor(
+      Local<String> name, AccessorGetterCallback getter,
+      AccessorSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+  void SetAccessor(
+      Local<Name> name, AccessorNameGetterCallback getter,
+      AccessorNameSetterCallback setter = 0, Local<Value> data = Local<Value>(),
+      AccessControl settings = DEFAULT, PropertyAttribute attribute = None,
+      Local<AccessorSignature> signature = Local<AccessorSignature>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string is accessed on objects created
+   * from this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * SetNamedPropertyHandler() is different from SetHandler(), in
+   * that the latter can intercept symbol-named properties as well as
+   * string-named properties when called with a
+   * NamedPropertyHandlerConfiguration. New code should use SetHandler().
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if a property is present,
+   *   and if present, get its attributes.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the named
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetNamedPropertyHandler(NamedPropertyGetterCallback getter,
+                               NamedPropertySetterCallback setter = 0,
+                               NamedPropertyQueryCallback query = 0,
+                               NamedPropertyDeleterCallback deleter = 0,
+                               NamedPropertyEnumeratorCallback enumerator = 0,
+                               Local<Value> data = Local<Value>());
+
+  /**
+   * Sets a named property handler on the object template.
+   *
+   * Whenever a property whose name is a string or a symbol is accessed on
+   * objects created from this object template, the provided callback is
+   * invoked instead of accessing the property directly on the JavaScript
+   * object.
+   *
+   * @param configuration The NamedPropertyHandlerConfiguration that defines the
+   * callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const NamedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * \param getter The callback to invoke when getting a property.
+   * \param setter The callback to invoke when setting a property.
+   * \param query The callback to invoke to check if an object has a property.
+   * \param deleter The callback to invoke when deleting a property.
+   * \param enumerator The callback to invoke to enumerate all the indexed
+   *   properties of an object.
+   * \param data A piece of data that will be passed to the callbacks
+   *   whenever they are invoked.
+   */
+  // TODO(dcarney): deprecate
+  void SetIndexedPropertyHandler(
+      IndexedPropertyGetterCallback getter,
+      IndexedPropertySetterCallback setter = 0,
+      IndexedPropertyQueryCallback query = 0,
+      IndexedPropertyDeleterCallback deleter = 0,
+      IndexedPropertyEnumeratorCallback enumerator = 0,
+      Local<Value> data = Local<Value>()) {
+    SetHandler(IndexedPropertyHandlerConfiguration(getter, setter, query,
+                                                   deleter, enumerator, data));
+  }
+
+  /**
+   * Sets an indexed property handler on the object template.
+   *
+   * Whenever an indexed property is accessed on objects created from
+   * this object template, the provided callback is invoked instead of
+   * accessing the property directly on the JavaScript object.
+   *
+   * @param configuration The IndexedPropertyHandlerConfiguration that defines
+   * the callbacks to invoke when accessing a property.
+   */
+  void SetHandler(const IndexedPropertyHandlerConfiguration& configuration);
+
+  /**
+   * Sets the callback to be used when calling instances created from
+   * this template as a function.  If no callback is set, instances
+   * behave like normal JavaScript objects that cannot be called as a
+   * function.
+   */
+  void SetCallAsFunctionHandler(FunctionCallback callback,
+                                Local<Value> data = Local<Value>());
+
+  /**
+   * Mark object instances of the template as undetectable.
+   *
+   * In many ways, undetectable objects behave as though they are not
+   * there.  They behave like 'undefined' in conditionals and when
+   * printed.  However, properties can be accessed and called as on
+   * normal objects.
+   */
+  void MarkAsUndetectable();
+
+  /**
+   * Sets access check callback on the object template and enables access
+   * checks.
+   *
+   * When accessing properties on instances of this object template,
+   * the access check callback will be called to determine whether or
+   * not to allow cross-context access to the properties.
+   */
+  void SetAccessCheckCallback(AccessCheckCallback callback,
+                              Local<Value> data = Local<Value>());
+
+  /**
+   * Like SetAccessCheckCallback but invokes an interceptor on failed access
+   * checks instead of looking up all-can-read properties. You can only use
+   * either this method or SetAccessCheckCallback, but not both at the same
+   * time.
+   */
+  void SetAccessCheckCallbackAndHandler(
+      AccessCheckCallback callback,
+      const NamedPropertyHandlerConfiguration& named_handler,
+      const IndexedPropertyHandlerConfiguration& indexed_handler,
+      Local<Value> data = Local<Value>());
+
+  /**
+   * Gets the number of internal fields for objects generated from
+   * this template.
+   */
+  int InternalFieldCount();
+
+  /**
+   * Sets the number of internal fields for objects generated from
+   * this template.
+   */
+  void SetInternalFieldCount(int value);
+
+  /**
+   * Returns true if the object will be an immutable prototype exotic object.
+   */
+  bool IsImmutableProto();
+
+  /**
+   * Makes the ObjectTempate for an immutable prototype exotic object, with an
+   * immutable __proto__.
+   */
+  void SetImmutableProto();
+
+ private:
+  ObjectTemplate();
+  static Local<ObjectTemplate> New(internal::Isolate* isolate,
+                                   Local<FunctionTemplate> constructor);
+  friend class FunctionTemplate;
+};
+
+/**
+ * A Signature specifies which receiver is valid for a function.
+ *
+ * A receiver matches a given signature if the receiver (or any of its
+ * hidden prototypes) was created from the signature's FunctionTemplate, or
+ * from a FunctionTemplate that inherits directly or indirectly from the
+ * signature's FunctionTemplate.
+ */
+class V8_EXPORT Signature : public Data {
+ public:
+  static Local<Signature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  Signature();
+};
+
+
+/**
+ * An AccessorSignature specifies which receivers are valid parameters
+ * to an accessor callback.
+ */
+class V8_EXPORT AccessorSignature : public Data {
+ public:
+  static Local<AccessorSignature> New(
+      Isolate* isolate,
+      Local<FunctionTemplate> receiver = Local<FunctionTemplate>());
+
+ private:
+  AccessorSignature();
+};
+
+
+// --- Extensions ---
+
+class V8_EXPORT ExternalOneByteStringResourceImpl
+    : public String::ExternalOneByteStringResource {
+ public:
+  ExternalOneByteStringResourceImpl() : data_(0), length_(0) {}
+  ExternalOneByteStringResourceImpl(const char* data, size_t length)
+      : data_(data), length_(length) {}
+  const char* data() const { return data_; }
+  size_t length() const { return length_; }
+
+ private:
+  const char* data_;
+  size_t length_;
+};
+
+/**
+ * Ignore
+ */
+class V8_EXPORT Extension {  // NOLINT
+ public:
+  // Note that the strings passed into this constructor must live as long
+  // as the Extension itself.
+  Extension(const char* name,
+            const char* source = 0,
+            int dep_count = 0,
+            const char** deps = 0,
+            int source_length = -1);
+  virtual ~Extension() { }
+  virtual Local<FunctionTemplate> GetNativeFunctionTemplate(
+      Isolate* isolate, Local<String> name) {
+    return Local<FunctionTemplate>();
+  }
+
+  const char* name() const { return name_; }
+  size_t source_length() const { return source_length_; }
+  const String::ExternalOneByteStringResource* source() const {
+    return &source_; }
+  int dependency_count() { return dep_count_; }
+  const char** dependencies() { return deps_; }
+  void set_auto_enable(bool value) { auto_enable_ = value; }
+  bool auto_enable() { return auto_enable_; }
+
+  // Disallow copying and assigning.
+  Extension(const Extension&) = delete;
+  void operator=(const Extension&) = delete;
+
+ private:
+  const char* name_;
+  size_t source_length_;  // expected to initialize before source_
+  ExternalOneByteStringResourceImpl source_;
+  int dep_count_;
+  const char** deps_;
+  bool auto_enable_;
+};
+
+
+void V8_EXPORT RegisterExtension(Extension* extension);
+
+
+// --- Statics ---
+
+V8_INLINE Local<Primitive> Undefined(Isolate* isolate);
+V8_INLINE Local<Primitive> Null(Isolate* isolate);
+V8_INLINE Local<Boolean> True(Isolate* isolate);
+V8_INLINE Local<Boolean> False(Isolate* isolate);
+
+/**
+ * A set of constraints that specifies the limits of the runtime's memory use.
+ * You must set the heap size before initializing the VM - the size cannot be
+ * adjusted after the VM is initialized.
+ *
+ * If you are using threads then you should hold the V8::Locker lock while
+ * setting the stack limit and you must set a non-default stack limit separately
+ * for each thread.
+ *
+ * The arguments for set_max_semi_space_size, set_max_old_space_size,
+ * set_max_executable_size, set_code_range_size specify limits in MB.
+ */
+class V8_EXPORT ResourceConstraints {
+ public:
+  ResourceConstraints();
+
+  /**
+   * Configures the constraints with reasonable default values based on the
+   * capabilities of the current device the VM is running on.
+   *
+   * \param physical_memory The total amount of physical memory on the current
+   *   device, in bytes.
+   * \param virtual_memory_limit The amount of virtual memory on the current
+   *   device, in bytes, or zero, if there is no limit.
+   */
+  void ConfigureDefaults(uint64_t physical_memory,
+                         uint64_t virtual_memory_limit);
+
+  int max_semi_space_size() const { return max_semi_space_size_; }
+  void set_max_semi_space_size(int limit_in_mb) {
+    max_semi_space_size_ = limit_in_mb;
+  }
+  int max_old_space_size() const { return max_old_space_size_; }
+  void set_max_old_space_size(int limit_in_mb) {
+    max_old_space_size_ = limit_in_mb;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    int max_executable_size() const) {
+    return max_executable_size_;
+  }
+  V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
+                    void set_max_executable_size(int limit_in_mb)) {
+    max_executable_size_ = limit_in_mb;
+  }
+  uint32_t* stack_limit() const { return stack_limit_; }
+  // Sets an address beyond which the VM's stack may not grow.
+  void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
+  size_t code_range_size() const { return code_range_size_; }
+  void set_code_range_size(size_t limit_in_mb) {
+    code_range_size_ = limit_in_mb;
+  }
+  size_t max_zone_pool_size() const { return max_zone_pool_size_; }
+  void set_max_zone_pool_size(const size_t bytes) {
+    max_zone_pool_size_ = bytes;
+  }
+
+ private:
+  int max_semi_space_size_;
+  int max_old_space_size_;
+  int max_executable_size_;
+  uint32_t* stack_limit_;
+  size_t code_range_size_;
+  size_t max_zone_pool_size_;
+};
+
+
+// --- Exceptions ---
+
+
+typedef void (*FatalErrorCallback)(const char* location, const char* message);
+
+typedef void (*OOMErrorCallback)(const char* location, bool is_heap_oom);
+
+typedef void (*MessageCallback)(Local<Message> message, Local<Value> data);
+
+// --- Tracing ---
+
+typedef void (*LogEventCallback)(const char* name, int event);
+
+/**
+ * Create new error objects by calling the corresponding error object
+ * constructor with the message.
+ */
+class V8_EXPORT Exception {
+ public:
+  static Local<Value> RangeError(Local<String> message);
+  static Local<Value> ReferenceError(Local<String> message);
+  static Local<Value> SyntaxError(Local<String> message);
+  static Local<Value> TypeError(Local<String> message);
+  static Local<Value> Error(Local<String> message);
+
+  /**
+   * Creates an error message for the given exception.
+   * Will try to reconstruct the original stack trace from the exception value,
+   * or capture the current stack trace if not available.
+   */
+  static Local<Message> CreateMessage(Isolate* isolate, Local<Value> exception);
+  V8_DEPRECATED("Use version with an Isolate*",
+                static Local<Message> CreateMessage(Local<Value> exception));
+
+  /**
+   * Returns the original stack trace that was captured at the creation time
+   * of a given exception, or an empty handle if not available.
+   */
+  static Local<StackTrace> GetStackTrace(Local<Value> exception);
+};
+
+
+// --- Counters Callbacks ---
+
+typedef int* (*CounterLookupCallback)(const char* name);
+
+typedef void* (*CreateHistogramCallback)(const char* name,
+                                         int min,
+                                         int max,
+                                         size_t buckets);
+
+typedef void (*AddHistogramSampleCallback)(void* histogram, int sample);
+
+// --- Memory Allocation Callback ---
+enum ObjectSpace {
+  kObjectSpaceNewSpace = 1 << 0,
+  kObjectSpaceOldSpace = 1 << 1,
+  kObjectSpaceCodeSpace = 1 << 2,
+  kObjectSpaceMapSpace = 1 << 3,
+  kObjectSpaceLoSpace = 1 << 4,
+  kObjectSpaceAll = kObjectSpaceNewSpace | kObjectSpaceOldSpace |
+                    kObjectSpaceCodeSpace | kObjectSpaceMapSpace |
+                    kObjectSpaceLoSpace
+};
+
+  enum AllocationAction {
+    kAllocationActionAllocate = 1 << 0,
+    kAllocationActionFree = 1 << 1,
+    kAllocationActionAll = kAllocationActionAllocate | kAllocationActionFree
+  };
+
+// --- Enter/Leave Script Callback ---
+typedef void (*BeforeCallEnteredCallback)(Isolate*);
+typedef void (*CallCompletedCallback)(Isolate*);
+typedef void (*DeprecatedCallCompletedCallback)();
+
+/**
+ * HostImportDynamicallyCallback is called when we require the
+ * embedder to load a module. This is used as part of the dynamic
+ * import syntax. The behavior of this callback is not specified in
+ * EcmaScript.
+ *
+ * The referrer is the name of the file which calls the dynamic
+ * import. The referrer can be used to resolve the module location.
+ *
+ * The specifier is the name of the module that should be imported.
+ *
+ * The DynamicImportResult object is used to signal success or failure
+ * by calling it's respective methods.
+ *
+ */
+typedef void (*HostImportModuleDynamicallyCallback)(
+    Isolate* isolate, Local<String> referrer, Local<String> specifier,
+    Local<DynamicImportResult> result);
+
+/**
+ * PromiseHook with type kInit is called when a new promise is
+ * created. When a new promise is created as part of the chain in the
+ * case of Promise.then or in the intermediate promises created by
+ * Promise.{race, all}/AsyncFunctionAwait, we pass the parent promise
+ * otherwise we pass undefined.
+ *
+ * PromiseHook with type kResolve is called at the beginning of
+ * resolve or reject function defined by CreateResolvingFunctions.
+ *
+ * PromiseHook with type kBefore is called at the beginning of the
+ * PromiseReactionJob.
+ *
+ * PromiseHook with type kAfter is called right at the end of the
+ * PromiseReactionJob.
+ */
+enum class PromiseHookType { kInit, kResolve, kBefore, kAfter };
+
+typedef void (*PromiseHook)(PromiseHookType type, Local<Promise> promise,
+                            Local<Value> parent);
+
+// --- Promise Reject Callback ---
+enum PromiseRejectEvent {
+  kPromiseRejectWithNoHandler = 0,
+  kPromiseHandlerAddedAfterReject = 1
+};
+
+class PromiseRejectMessage {
+ public:
+  PromiseRejectMessage(Local<Promise> promise, PromiseRejectEvent event,
+                       Local<Value> value, Local<StackTrace> stack_trace)
+      : promise_(promise),
+        event_(event),
+        value_(value),
+        stack_trace_(stack_trace) {}
+
+  V8_INLINE Local<Promise> GetPromise() const { return promise_; }
+  V8_INLINE PromiseRejectEvent GetEvent() const { return event_; }
+  V8_INLINE Local<Value> GetValue() const { return value_; }
+
+  V8_DEPRECATED("Use v8::Exception::CreateMessage(GetValue())->GetStackTrace()",
+                V8_INLINE Local<StackTrace> GetStackTrace() const) {
+    return stack_trace_;
+  }
+
+ private:
+  Local<Promise> promise_;
+  PromiseRejectEvent event_;
+  Local<Value> value_;
+  Local<StackTrace> stack_trace_;
+};
+
+typedef void (*PromiseRejectCallback)(PromiseRejectMessage message);
+
+// --- Microtasks Callbacks ---
+typedef void (*MicrotasksCompletedCallback)(Isolate*);
+typedef void (*MicrotaskCallback)(void* data);
+
+
+/**
+ * Policy for running microtasks:
+ *   - explicit: microtasks are invoked with Isolate::RunMicrotasks() method;
+ *   - scoped: microtasks invocation is controlled by MicrotasksScope objects;
+ *   - auto: microtasks are invoked when the script call depth decrements
+ *           to zero.
+ */
+enum class MicrotasksPolicy { kExplicit, kScoped, kAuto };
+
+
+/**
+ * This scope is used to control microtasks when kScopeMicrotasksInvocation
+ * is used on Isolate. In this mode every non-primitive call to V8 should be
+ * done inside some MicrotasksScope.
+ * Microtasks are executed when topmost MicrotasksScope marked as kRunMicrotasks
+ * exits.
+ * kDoNotRunMicrotasks should be used to annotate calls not intended to trigger
+ * microtasks.
+ */
+class V8_EXPORT MicrotasksScope {
+ public:
+  enum Type { kRunMicrotasks, kDoNotRunMicrotasks };
+
+  MicrotasksScope(Isolate* isolate, Type type);
+  ~MicrotasksScope();
+
+  /**
+   * Runs microtasks if no kRunMicrotasks scope is currently active.
+   */
+  static void PerformCheckpoint(Isolate* isolate);
+
+  /**
+   * Returns current depth of nested kRunMicrotasks scopes.
+   */
+  static int GetCurrentDepth(Isolate* isolate);
+
+  /**
+   * Returns true while microtasks are being executed.
+   */
+  static bool IsRunningMicrotasks(Isolate* isolate);
+
+  // Prevent copying.
+  MicrotasksScope(const MicrotasksScope&) = delete;
+  MicrotasksScope& operator=(const MicrotasksScope&) = delete;
+
+ private:
+  internal::Isolate* const isolate_;
+  bool run_;
+};
+
+
+// --- Failed Access Check Callback ---
+typedef void (*FailedAccessCheckCallback)(Local<Object> target,
+                                          AccessType type,
+                                          Local<Value> data);
+
+// --- AllowCodeGenerationFromStrings callbacks ---
+
+/**
+ * Callback to check if code generation from strings is allowed. See
+ * Context::AllowCodeGenerationFromStrings.
+ */
+typedef bool (*AllowCodeGenerationFromStringsCallback)(Local<Context> context);
+
+// --- WASM compilation callbacks ---
+typedef bool (*ExtensionCallback)(const FunctionCallbackInfo<Value>&);
+
+// --- Garbage Collection Callbacks ---
+
+/**
+ * Applications can register callback functions which will be called before and
+ * after certain garbage collection operations.  Allocations are not allowed in
+ * the callback functions, you therefore cannot manipulate objects (set or
+ * delete properties for example) since it is possible such operations will
+ * result in the allocation of objects.
+ */
+enum GCType {
+  kGCTypeScavenge = 1 << 0,
+  kGCTypeMarkSweepCompact = 1 << 1,
+  kGCTypeIncrementalMarking = 1 << 2,
+  kGCTypeProcessWeakCallbacks = 1 << 3,
+  kGCTypeAll = kGCTypeScavenge | kGCTypeMarkSweepCompact |
+               kGCTypeIncrementalMarking | kGCTypeProcessWeakCallbacks
+};
+
+/**
+ * GCCallbackFlags is used to notify additional information about the GC
+ * callback.
+ *   - kGCCallbackFlagConstructRetainedObjectInfos: The GC callback is for
+ *     constructing retained object infos.
+ *   - kGCCallbackFlagForced: The GC callback is for a forced GC for testing.
+ *   - kGCCallbackFlagSynchronousPhantomCallbackProcessing: The GC callback
+ *     is called synchronously without getting posted to an idle task.
+ *   - kGCCallbackFlagCollectAllAvailableGarbage: The GC callback is called
+ *     in a phase where V8 is trying to collect all available garbage
+ *     (e.g., handling a low memory notification).
+ *   - kGCCallbackScheduleIdleGarbageCollection: The GC callback is called to
+ *     trigger an idle garbage collection.
+ */
+enum GCCallbackFlags {
+  kNoGCCallbackFlags = 0,
+  kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1,
+  kGCCallbackFlagForced = 1 << 2,
+  kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3,
+  kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4,
+  kGCCallbackFlagCollectAllExternalMemory = 1 << 5,
+  kGCCallbackScheduleIdleGarbageCollection = 1 << 6,
+};
+
+typedef void (*GCCallback)(GCType type, GCCallbackFlags flags);
+
+typedef void (*InterruptCallback)(Isolate* isolate, void* data);
+
+
+/**
+ * Collection of V8 heap information.
+ *
+ * Instances of this class can be passed to v8::V8::HeapStatistics to
+ * get heap statistics from V8.
+ */
+class V8_EXPORT HeapStatistics {
+ public:
+  HeapStatistics();
+  size_t total_heap_size() { return total_heap_size_; }
+  size_t total_heap_size_executable() { return total_heap_size_executable_; }
+  size_t total_physical_size() { return total_physical_size_; }
+  size_t total_available_size() { return total_available_size_; }
+  size_t used_heap_size() { return used_heap_size_; }
+  size_t heap_size_limit() { return heap_size_limit_; }
+  size_t malloced_memory() { return malloced_memory_; }
+  size_t peak_malloced_memory() { return peak_malloced_memory_; }
+
+  /**
+   * Returns a 0/1 boolean, which signifies whether the V8 overwrite heap
+   * garbage with a bit pattern.
+   */
+  size_t does_zap_garbage() { return does_zap_garbage_; }
+
+ private:
+  size_t total_heap_size_;
+  size_t total_heap_size_executable_;
+  size_t total_physical_size_;
+  size_t total_available_size_;
+  size_t used_heap_size_;
+  size_t heap_size_limit_;
+  size_t malloced_memory_;
+  size_t peak_malloced_memory_;
+  bool does_zap_garbage_;
+
+  friend class V8;
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapSpaceStatistics {
+ public:
+  HeapSpaceStatistics();
+  const char* space_name() { return space_name_; }
+  size_t space_size() { return space_size_; }
+  size_t space_used_size() { return space_used_size_; }
+  size_t space_available_size() { return space_available_size_; }
+  size_t physical_space_size() { return physical_space_size_; }
+
+ private:
+  const char* space_name_;
+  size_t space_size_;
+  size_t space_used_size_;
+  size_t space_available_size_;
+  size_t physical_space_size_;
+
+  friend class Isolate;
+};
+
+
+class V8_EXPORT HeapObjectStatistics {
+ public:
+  HeapObjectStatistics();
+  const char* object_type() { return object_type_; }
+  const char* object_sub_type() { return object_sub_type_; }
+  size_t object_count() { return object_count_; }
+  size_t object_size() { return object_size_; }
+
+ private:
+  const char* object_type_;
+  const char* object_sub_type_;
+  size_t object_count_;
+  size_t object_size_;
+
+  friend class Isolate;
+};
+
+class V8_EXPORT HeapCodeStatistics {
+ public:
+  HeapCodeStatistics();
+  size_t code_and_metadata_size() { return code_and_metadata_size_; }
+  size_t bytecode_and_metadata_size() { return bytecode_and_metadata_size_; }
+
+ private:
+  size_t code_and_metadata_size_;
+  size_t bytecode_and_metadata_size_;
+
+  friend class Isolate;
+};
+
+class RetainedObjectInfo;
+
+
+/**
+ * FunctionEntryHook is the type of the profile entry hook called at entry to
+ * any generated function when function-level profiling is enabled.
+ *
+ * \param function the address of the function that's being entered.
+ * \param return_addr_location points to a location on stack where the machine
+ *    return address resides. This can be used to identify the caller of
+ *    \p function, and/or modified to divert execution when \p function exits.
+ *
+ * \note the entry hook must not cause garbage collection.
+ */
+typedef void (*FunctionEntryHook)(uintptr_t function,
+                                  uintptr_t return_addr_location);
+
+/**
+ * A JIT code event is issued each time code is added, moved or removed.
+ *
+ * \note removal events are not currently issued.
+ */
+struct JitCodeEvent {
+  enum EventType {
+    CODE_ADDED,
+    CODE_MOVED,
+    CODE_REMOVED,
+    CODE_ADD_LINE_POS_INFO,
+    CODE_START_LINE_INFO_RECORDING,
+    CODE_END_LINE_INFO_RECORDING
+  };
+  // Definition of the code position type. The "POSITION" type means the place
+  // in the source code which are of interest when making stack traces to
+  // pin-point the source location of a stack frame as close as possible.
+  // The "STATEMENT_POSITION" means the place at the beginning of each
+  // statement, and is used to indicate possible break locations.
+  enum PositionType { POSITION, STATEMENT_POSITION };
+
+  // Type of event.
+  EventType type;
+  // Start of the instructions.
+  void* code_start;
+  // Size of the instructions.
+  size_t code_len;
+  // Script info for CODE_ADDED event.
+  Local<UnboundScript> script;
+  // User-defined data for *_LINE_INFO_* event. It's used to hold the source
+  // code line information which is returned from the
+  // CODE_START_LINE_INFO_RECORDING event. And it's passed to subsequent
+  // CODE_ADD_LINE_POS_INFO and CODE_END_LINE_INFO_RECORDING events.
+  void* user_data;
+
+  struct name_t {
+    // Name of the object associated with the code, note that the string is not
+    // zero-terminated.
+    const char* str;
+    // Number of chars in str.
+    size_t len;
+  };
+
+  struct line_info_t {
+    // PC offset
+    size_t offset;
+    // Code postion
+    size_t pos;
+    // The position type.
+    PositionType position_type;
+  };
+
+  union {
+    // Only valid for CODE_ADDED.
+    struct name_t name;
+
+    // Only valid for CODE_ADD_LINE_POS_INFO
+    struct line_info_t line_info;
+
+    // New location of instructions. Only valid for CODE_MOVED.
+    void* new_code_start;
+  };
+};
+
+/**
+ * Option flags passed to the SetRAILMode function.
+ * See documentation https://developers.google.com/web/tools/chrome-devtools/
+ * profile/evaluate-performance/rail
+ */
+enum RAILMode {
+  // Response performance mode: In this mode very low virtual machine latency
+  // is provided. V8 will try to avoid JavaScript execution interruptions.
+  // Throughput may be throttled.
+  PERFORMANCE_RESPONSE,
+  // Animation performance mode: In this mode low virtual machine latency is
+  // provided. V8 will try to avoid as many JavaScript execution interruptions
+  // as possible. Throughput may be throttled. This is the default mode.
+  PERFORMANCE_ANIMATION,
+  // Idle performance mode: The embedder is idle. V8 can complete deferred work
+  // in this mode.
+  PERFORMANCE_IDLE,
+  // Load performance mode: In this mode high throughput is provided. V8 may
+  // turn off latency optimizations.
+  PERFORMANCE_LOAD
+};
+
+/**
+ * Option flags passed to the SetJitCodeEventHandler function.
+ */
+enum JitCodeEventOptions {
+  kJitCodeEventDefault = 0,
+  // Generate callbacks for already existent code.
+  kJitCodeEventEnumExisting = 1
+};
+
+
+/**
+ * Callback function passed to SetJitCodeEventHandler.
+ *
+ * \param event code add, move or removal event.
+ */
+typedef void (*JitCodeEventHandler)(const JitCodeEvent* event);
+
+
+/**
+ * Interface for iterating through all external resources in the heap.
+ */
+class V8_EXPORT ExternalResourceVisitor {  // NOLINT
+ public:
+  virtual ~ExternalResourceVisitor() {}
+  virtual void VisitExternalString(Local<String> string) {}
+};
+
+
+/**
+ * Interface for iterating through all the persistent handles in the heap.
+ */
+class V8_EXPORT PersistentHandleVisitor {  // NOLINT
+ public:
+  virtual ~PersistentHandleVisitor() {}
+  virtual void VisitPersistentHandle(Persistent<Value>* value,
+                                     uint16_t class_id) {}
+};
+
+/**
+ * Memory pressure level for the MemoryPressureNotification.
+ * kNone hints V8 that there is no memory pressure.
+ * kModerate hints V8 to speed up incremental garbage collection at the cost of
+ * of higher latency due to garbage collection pauses.
+ * kCritical hints V8 to free memory as soon as possible. Garbage collection
+ * pauses at this level will be large.
+ */
+enum class MemoryPressureLevel { kNone, kModerate, kCritical };
+
+/**
+ * Interface for tracing through the embedder heap. During a v8 garbage
+ * collection, v8 collects hidden fields of all potential wrappers, and at the
+ * end of its marking phase iterates the collection and asks the embedder to
+ * trace through its heap and use reporter to report each JavaScript object
+ * reachable from any of the given wrappers.
+ *
+ * Before the first call to the TraceWrappersFrom function TracePrologue will be
+ * called. When the garbage collection cycle is finished, TraceEpilogue will be
+ * called.
+ */
+class V8_EXPORT EmbedderHeapTracer {
+ public:
+  enum ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION };
+
+  struct AdvanceTracingActions {
+    explicit AdvanceTracingActions(ForceCompletionAction force_completion_)
+        : force_completion(force_completion_) {}
+
+    ForceCompletionAction force_completion;
+  };
+
+  /**
+   * Called by v8 to register internal fields of found wrappers.
+   *
+   * The embedder is expected to store them somewhere and trace reachable
+   * wrappers from them when called through |AdvanceTracing|.
+   */
+  virtual void RegisterV8References(
+      const std::vector<std::pair<void*, void*> >& embedder_fields) = 0;
+
+  /**
+   * Called at the beginning of a GC cycle.
+   */
+  virtual void TracePrologue() = 0;
+
+  /**
+   * Called to to make a tracing step in the embedder.
+   *
+   * The embedder is expected to trace its heap starting from wrappers reported
+   * by RegisterV8References method, and report back all reachable wrappers.
+   * Furthermore, the embedder is expected to stop tracing by the given
+   * deadline.
+   *
+   * Returns true if there is still work to do.
+   */
+  virtual bool AdvanceTracing(double deadline_in_ms,
+                              AdvanceTracingActions actions) = 0;
+
+  /**
+   * Called at the end of a GC cycle.
+   *
+   * Note that allocation is *not* allowed within |TraceEpilogue|.
+   */
+  virtual void TraceEpilogue() = 0;
+
+  /**
+   * Called upon entering the final marking pause. No more incremental marking
+   * steps will follow this call.
+   */
+  virtual void EnterFinalPause() = 0;
+
+  /**
+   * Called when tracing is aborted.
+   *
+   * The embedder is expected to throw away all intermediate data and reset to
+   * the initial state.
+   */
+  virtual void AbortTracing() = 0;
+
+  /**
+   * Returns the number of wrappers that are still to be traced by the embedder.
+   */
+  virtual size_t NumberOfWrappersToTrace() { return 0; }
+
+ protected:
+  virtual ~EmbedderHeapTracer() = default;
+};
+
+/**
+ * Callback and supporting data used in SnapshotCreator to implement embedder
+ * logic to serialize internal fields.
+ */
+struct SerializeInternalFieldsCallback {
+  typedef StartupData (*CallbackFunction)(Local<Object> holder, int index,
+                                          void* data);
+  SerializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                  void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  CallbackFunction callback;
+  void* data;
+};
+// Note that these fields are called "internal fields" in the API and called
+// "embedder fields" within V8.
+typedef SerializeInternalFieldsCallback SerializeEmbedderFieldsCallback;
+
+/**
+ * Callback and supporting data used to implement embedder logic to deserialize
+ * internal fields.
+ */
+struct DeserializeInternalFieldsCallback {
+  typedef void (*CallbackFunction)(Local<Object> holder, int index,
+                                   StartupData payload, void* data);
+  DeserializeInternalFieldsCallback(CallbackFunction function = nullptr,
+                                    void* data_arg = nullptr)
+      : callback(function), data(data_arg) {}
+  void (*callback)(Local<Object> holder, int index, StartupData payload,
+                   void* data);
+  void* data;
+};
+typedef DeserializeInternalFieldsCallback DeserializeEmbedderFieldsCallback;
+
+/**
+ * Isolate represents an isolated instance of the V8 engine.  V8 isolates have
+ * completely separate states.  Objects from one isolate must not be used in
+ * other isolates.  The embedder can create multiple isolates and use them in
+ * parallel in multiple threads.  An isolate can be entered by at most one
+ * thread at any given time.  The Locker/Unlocker API must be used to
+ * synchronize.
+ */
+class V8_EXPORT Isolate {
+ public:
+  /**
+   * Initial configuration parameters for a new Isolate.
+   */
+  struct CreateParams {
+    CreateParams()
+        : entry_hook(nullptr),
+          code_event_handler(nullptr),
+          snapshot_blob(nullptr),
+          counter_lookup_callback(nullptr),
+          create_histogram_callback(nullptr),
+          add_histogram_sample_callback(nullptr),
+          array_buffer_allocator(nullptr),
+          external_references(nullptr),
+          allow_atomics_wait(true),
+          host_import_module_dynamically_callback_(nullptr) {}
+
+    /**
+     * The optional entry_hook allows the host application to provide the
+     * address of a function that's invoked on entry to every V8-generated
+     * function.  Note that entry_hook is invoked at the very start of each
+     * generated function.
+     * An entry_hook can only be provided in no-snapshot builds; in snapshot
+     * builds it must be nullptr.
+     */
+    FunctionEntryHook entry_hook;
+
+    /**
+     * Allows the host application to provide the address of a function that is
+     * notified each time code is added, moved or removed.
+     */
+    JitCodeEventHandler code_event_handler;
+
+    /**
+     * ResourceConstraints to use for the new Isolate.
+     */
+    ResourceConstraints constraints;
+
+    /**
+     * Explicitly specify a startup snapshot blob. The embedder owns the blob.
+     */
+    StartupData* snapshot_blob;
+
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * statistics counters.
+     */
+    CounterLookupCallback counter_lookup_callback;
+
+    /**
+     * Enables the host application to provide a mechanism for recording
+     * histograms. The CreateHistogram function returns a
+     * histogram which will later be passed to the AddHistogramSample
+     * function.
+     */
+    CreateHistogramCallback create_histogram_callback;
+    AddHistogramSampleCallback add_histogram_sample_callback;
+
+    /**
+     * The ArrayBuffer::Allocator to use for allocating and freeing the backing
+     * store of ArrayBuffers.
+     */
+    ArrayBuffer::Allocator* array_buffer_allocator;
+
+    /**
+     * Specifies an optional nullptr-terminated array of raw addresses in the
+     * embedder that V8 can match against during serialization and use for
+     * deserialization. This array and its content must stay valid for the
+     * entire lifetime of the isolate.
+     */
+    intptr_t* external_references;
+
+    /**
+     * Whether calling Atomics.wait (a function that may block) is allowed in
+     * this isolate. This can also be configured via SetAllowAtomicsWait.
+     */
+    bool allow_atomics_wait;
+
+    /**
+     * This is an unfinished experimental feature, and is only exposed
+     * here for internal testing purposes. DO NOT USE.
+     *
+     * This specifies the callback called by the upcoming dynamic
+     * import() language feature to load modules.
+     */
+    HostImportModuleDynamicallyCallback
+        host_import_module_dynamically_callback_;
+  };
+
+
+  /**
+   * Stack-allocated class which sets the isolate for all operations
+   * executed within a local scope.
+   */
+  class V8_EXPORT Scope {
+   public:
+    explicit Scope(Isolate* isolate) : isolate_(isolate) {
+      isolate->Enter();
+    }
+
+    ~Scope() { isolate_->Exit(); }
+
+    // Prevent copying of Scope objects.
+    Scope(const Scope&) = delete;
+    Scope& operator=(const Scope&) = delete;
+
+   private:
+    Isolate* const isolate_;
+  };
+
+
+  /**
+   * Assert that no Javascript code is invoked.
+   */
+  class V8_EXPORT DisallowJavascriptExecutionScope {
+   public:
+    enum OnFailure { CRASH_ON_FAILURE, THROW_ON_FAILURE };
+
+    DisallowJavascriptExecutionScope(Isolate* isolate, OnFailure on_failure);
+    ~DisallowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    DisallowJavascriptExecutionScope(const DisallowJavascriptExecutionScope&) =
+        delete;
+    DisallowJavascriptExecutionScope& operator=(
+        const DisallowJavascriptExecutionScope&) = delete;
+
+   private:
+    bool on_failure_;
+    void* internal_;
+  };
+
+
+  /**
+   * Introduce exception to DisallowJavascriptExecutionScope.
+   */
+  class V8_EXPORT AllowJavascriptExecutionScope {
+   public:
+    explicit AllowJavascriptExecutionScope(Isolate* isolate);
+    ~AllowJavascriptExecutionScope();
+
+    // Prevent copying of Scope objects.
+    AllowJavascriptExecutionScope(const AllowJavascriptExecutionScope&) =
+        delete;
+    AllowJavascriptExecutionScope& operator=(
+        const AllowJavascriptExecutionScope&) = delete;
+
+   private:
+    void* internal_throws_;
+    void* internal_assert_;
+  };
+
+  /**
+   * Do not run microtasks while this scope is active, even if microtasks are
+   * automatically executed otherwise.
+   */
+  class V8_EXPORT SuppressMicrotaskExecutionScope {
+   public:
+    explicit SuppressMicrotaskExecutionScope(Isolate* isolate);
+    ~SuppressMicrotaskExecutionScope();
+
+    // Prevent copying of Scope objects.
+    SuppressMicrotaskExecutionScope(const SuppressMicrotaskExecutionScope&) =
+        delete;
+    SuppressMicrotaskExecutionScope& operator=(
+        const SuppressMicrotaskExecutionScope&) = delete;
+
+   private:
+    internal::Isolate* const isolate_;
+  };
+
+  /**
+   * Types of garbage collections that can be requested via
+   * RequestGarbageCollectionForTesting.
+   */
+  enum GarbageCollectionType {
+    kFullGarbageCollection,
+    kMinorGarbageCollection
+  };
+
+  /**
+   * Features reported via the SetUseCounterCallback callback. Do not change
+   * assigned numbers of existing items; add new features to the end of this
+   * list.
+   */
+  enum UseCounterFeature {
+    kUseAsm = 0,
+    kBreakIterator = 1,
+    kLegacyConst = 2,
+    kMarkDequeOverflow = 3,
+    kStoreBufferOverflow = 4,
+    kSlotsBufferOverflow = 5,
+    kObjectObserve = 6,
+    kForcedGC = 7,
+    kSloppyMode = 8,
+    kStrictMode = 9,
+    kStrongMode = 10,
+    kRegExpPrototypeStickyGetter = 11,
+    kRegExpPrototypeToString = 12,
+    kRegExpPrototypeUnicodeGetter = 13,
+    kIntlV8Parse = 14,
+    kIntlPattern = 15,
+    kIntlResolved = 16,
+    kPromiseChain = 17,
+    kPromiseAccept = 18,
+    kPromiseDefer = 19,
+    kHtmlCommentInExternalScript = 20,
+    kHtmlComment = 21,
+    kSloppyModeBlockScopedFunctionRedefinition = 22,
+    kForInInitializer = 23,
+    kArrayProtectorDirtied = 24,
+    kArraySpeciesModified = 25,
+    kArrayPrototypeConstructorModified = 26,
+    kArrayInstanceProtoModified = 27,
+    kArrayInstanceConstructorModified = 28,
+    kLegacyFunctionDeclaration = 29,
+    kRegExpPrototypeSourceGetter = 30,
+    kRegExpPrototypeOldFlagGetter = 31,
+    kDecimalWithLeadingZeroInStrictMode = 32,
+    kLegacyDateParser = 33,
+    kDefineGetterOrSetterWouldThrow = 34,
+    kFunctionConstructorReturnedUndefined = 35,
+    kAssigmentExpressionLHSIsCallInSloppy = 36,
+    kAssigmentExpressionLHSIsCallInStrict = 37,
+    kPromiseConstructorReturnedUndefined = 38,
+
+    // If you add new values here, you'll also need to update Chromium's:
+    // UseCounter.h, V8PerIsolateData.cpp, histograms.xml
+    kUseCounterFeatureCount  // This enum value must be last.
+  };
+
+  enum MessageErrorLevel {
+    kMessageLog = (1 << 0),
+    kMessageDebug = (1 << 1),
+    kMessageInfo = (1 << 2),
+    kMessageError = (1 << 3),
+    kMessageWarning = (1 << 4),
+    kMessageAll = kMessageLog | kMessageDebug | kMessageInfo | kMessageError |
+                  kMessageWarning,
+  };
+
+  typedef void (*UseCounterCallback)(Isolate* isolate,
+                                     UseCounterFeature feature);
+
+
+  /**
+   * Creates a new isolate.  Does not change the currently entered
+   * isolate.
+   *
+   * When an isolate is no longer used its resources should be freed
+   * by calling Dispose().  Using the delete operator is not allowed.
+   *
+   * V8::Initialize() must have run prior to this.
+   */
+  static Isolate* New(const CreateParams& params);
+
+  /**
+   * Returns the entered isolate for the current thread or NULL in
+   * case there is no current isolate.
+   *
+   * This method must not be invoked before V8::Initialize() was invoked.
+   */
+  static Isolate* GetCurrent();
+
+  /**
+   * Custom callback used by embedders to help V8 determine if it should abort
+   * when it throws and no internal handler is predicted to catch the
+   * exception. If --abort-on-uncaught-exception is used on the command line,
+   * then V8 will abort if either:
+   * - no custom callback is set.
+   * - the custom callback set returns true.
+   * Otherwise, the custom callback will not be called and V8 will not abort.
+   */
+  typedef bool (*AbortOnUncaughtExceptionCallback)(Isolate*);
+  void SetAbortOnUncaughtExceptionCallback(
+      AbortOnUncaughtExceptionCallback callback);
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to guide heuristics.
+   * It is allowed to call this function from another thread while
+   * the isolate is executing long running JavaScript code.
+   */
+  void MemoryPressureNotification(MemoryPressureLevel level);
+
+  /**
+   * Methods below this point require holding a lock (using Locker) in
+   * a multi-threaded environment.
+   */
+
+  /**
+   * Sets this isolate as the entered one for the current thread.
+   * Saves the previously entered one (if any), so that it can be
+   * restored when exiting.  Re-entering an isolate is allowed.
+   */
+  void Enter();
+
+  /**
+   * Exits this isolate by restoring the previously entered one in the
+   * current thread.  The isolate may still stay the same, if it was
+   * entered more than once.
+   *
+   * Requires: this == Isolate::GetCurrent().
+   */
+  void Exit();
+
+  /**
+   * Disposes the isolate.  The isolate must not be entered by any
+   * thread to be disposable.
+   */
+  void Dispose();
+
+  /**
+   * Dumps activated low-level V8 internal stats. This can be used instead
+   * of performing a full isolate disposal.
+   */
+  void DumpAndResetStats();
+
+  /**
+   * Discards all V8 thread-specific data for the Isolate. Should be used
+   * if a thread is terminating and it has used an Isolate that will outlive
+   * the thread -- all thread-specific data for an Isolate is discarded when
+   * an Isolate is disposed so this call is pointless if an Isolate is about
+   * to be Disposed.
+   */
+  void DiscardThreadSpecificMetadata();
+
+  /**
+   * Associate embedder-specific data with the isolate. |slot| has to be
+   * between 0 and GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE void SetData(uint32_t slot, void* data);
+
+  /**
+   * Retrieve embedder-specific data from the isolate.
+   * Returns NULL if SetData has never been called for the given |slot|.
+   */
+  V8_INLINE void* GetData(uint32_t slot);
+
+  /**
+   * Returns the maximum number of available embedder data slots. Valid slots
+   * are in the range of 0 - GetNumberOfDataSlots() - 1.
+   */
+  V8_INLINE static uint32_t GetNumberOfDataSlots();
+
+  /**
+   * Get statistics about the heap memory usage.
+   */
+  void GetHeapStatistics(HeapStatistics* heap_statistics);
+
+  /**
+   * Returns the number of spaces in the heap.
+   */
+  size_t NumberOfHeapSpaces();
+
+  /**
+   * Get the memory usage of a space in the heap.
+   *
+   * \param space_statistics The HeapSpaceStatistics object to fill in
+   *   statistics.
+   * \param index The index of the space to get statistics from, which ranges
+   *   from 0 to NumberOfHeapSpaces() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapSpaceStatistics(HeapSpaceStatistics* space_statistics,
+                              size_t index);
+
+  /**
+   * Returns the number of types of objects tracked in the heap at GC.
+   */
+  size_t NumberOfTrackedHeapObjectTypes();
+
+  /**
+   * Get statistics about objects in the heap.
+   *
+   * \param object_statistics The HeapObjectStatistics object to fill in
+   *   statistics of objects of given type, which were live in the previous GC.
+   * \param type_index The index of the type of object to fill details about,
+   *   which ranges from 0 to NumberOfTrackedHeapObjectTypes() - 1.
+   * \returns true on success.
+   */
+  bool GetHeapObjectStatisticsAtLastGC(HeapObjectStatistics* object_statistics,
+                                       size_t type_index);
+
+  /**
+   * Get statistics about code and its metadata in the heap.
+   *
+   * \param object_statistics The HeapCodeStatistics object to fill in
+   *   statistics of code, bytecode and their metadata.
+   * \returns true on success.
+   */
+  bool GetHeapCodeAndMetadataStatistics(HeapCodeStatistics* object_statistics);
+
+  /**
+   * Get a call stack sample from the isolate.
+   * \param state Execution state.
+   * \param frames Caller allocated buffer to store stack frames.
+   * \param frames_limit Maximum number of frames to capture. The buffer must
+   *                     be large enough to hold the number of frames.
+   * \param sample_info The sample info is filled up by the function
+   *                    provides number of actual captured stack frames and
+   *                    the current VM state.
+   * \note GetStackSample should only be called when the JS thread is paused or
+   *       interrupted. Otherwise the behavior is undefined.
+   */
+  void GetStackSample(const RegisterState& state, void** frames,
+                      size_t frames_limit, SampleInfo* sample_info);
+
+  /**
+   * Adjusts the amount of registered external memory. Used to give V8 an
+   * indication of the amount of externally allocated memory that is kept alive
+   * by JavaScript objects. V8 uses this to decide when to perform global
+   * garbage collections. Registering externally allocated memory will trigger
+   * global garbage collections more often than it would otherwise in an attempt
+   * to garbage collect the JavaScript objects that keep the externally
+   * allocated memory alive.
+   *
+   * \param change_in_bytes the change in externally allocated memory that is
+   *   kept alive by JavaScript objects.
+   * \returns the adjusted value.
+   */
+  V8_INLINE int64_t
+      AdjustAmountOfExternalAllocatedMemory(int64_t change_in_bytes);
+
+  /**
+   * Returns the number of phantom handles without callbacks that were reset
+   * by the garbage collector since the last call to this function.
+   */
+  size_t NumberOfPhantomHandleResetsSinceLastCall();
+
+  /**
+   * Returns heap profiler for this isolate. Will return NULL until the isolate
+   * is initialized.
+   */
+  HeapProfiler* GetHeapProfiler();
+
+  /**
+   * Returns CPU profiler for this isolate. Will return NULL unless the isolate
+   * is initialized. It is the embedder's responsibility to stop all CPU
+   * profiling activities if it has started any.
+   */
+  V8_DEPRECATE_SOON("CpuProfiler should be created with CpuProfiler::New call.",
+                    CpuProfiler* GetCpuProfiler());
+
+  /** Returns true if this isolate has a current context. */
+  bool InContext();
+
+  /**
+   * Returns the context of the currently running JavaScript, or the context
+   * on the top of the stack if no JavaScript is running.
+   */
+  Local<Context> GetCurrentContext();
+
+  /**
+   * Returns the context of the calling JavaScript code.  That is the
+   * context of the top-most JavaScript frame.  If there are no
+   * JavaScript frames an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON(
+      "Calling context concept is not compatible with tail calls, and will be "
+      "removed.",
+      Local<Context> GetCallingContext());
+
+  /** Returns the last context entered through V8's C++ API. */
+  Local<Context> GetEnteredContext();
+
+  /**
+   * Returns either the last context entered through V8's C++ API, or the
+   * context of the currently running microtask while processing microtasks.
+   * If a context is entered while executing a microtask, that context is
+   * returned.
+   */
+  Local<Context> GetEnteredOrMicrotaskContext();
+
+  /**
+   * Schedules an exception to be thrown when returning to JavaScript.  When an
+   * exception has been scheduled it is illegal to invoke any JavaScript
+   * operation; the caller must return immediately and only after the exception
+   * has been handled does it become legal to invoke JavaScript operations.
+   */
+  Local<Value> ThrowException(Local<Value> exception);
+
+  typedef void (*GCCallback)(Isolate* isolate, GCType type,
+                             GCCallbackFlags flags);
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCPrologueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  void RemoveGCPrologueCallback(GCCallback callback);
+
+  /**
+   * Sets the embedder heap tracer for the isolate.
+   */
+  void SetEmbedderHeapTracer(EmbedderHeapTracer* tracer);
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection. Allocations are allowed in the callback function,
+   * but the callback is not re-entrant: if the allocation inside it will
+   * trigger the garbage collection, the callback won't be called again.
+   * It is possible to specify the GCType filter for your callback. But it is
+   * not possible to register the same callback function two times with
+   * different GCType filters.
+   */
+  void AddGCEpilogueCallback(GCCallback callback,
+                             GCType gc_type_filter = kGCTypeAll);
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  void RemoveGCEpilogueCallback(GCCallback callback);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void TerminateExecution();
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   */
+  bool IsExecutionTerminating();
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   */
+  void CancelTerminateExecution();
+
+  /**
+   * Request V8 to interrupt long running JavaScript code and invoke
+   * the given |callback| passing the given |data| to it. After |callback|
+   * returns control will be returned to the JavaScript code.
+   * There may be a number of interrupt requests in flight.
+   * Can be called from another thread without acquiring a |Locker|.
+   * Registered |callback| must not reenter interrupted Isolate.
+   */
+  void RequestInterrupt(InterruptCallback callback, void* data);
+
+  /**
+   * Request garbage collection in this Isolate. It is only valid to call this
+   * function if --expose_gc was specified.
+   *
+   * This should only be used for testing purposes and not to enforce a garbage
+   * collection schedule. It has strong negative impact on the garbage
+   * collection performance. Use IdleNotificationDeadline() or
+   * LowMemoryNotification() instead to influence the garbage collection
+   * schedule.
+   */
+  void RequestGarbageCollectionForTesting(GarbageCollectionType type);
+
+  /**
+   * Set the callback to invoke for logging event.
+   */
+  void SetEventLogger(LogEventCallback that);
+
+  /**
+   * Adds a callback to notify the host application right before a script
+   * is about to run. If a script re-enters the runtime during executing, the
+   * BeforeCallEnteredCallback is invoked for each re-entrance.
+   * Executing scripts inside the callback will re-trigger the callback.
+   */
+  void AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Removes callback that was installed by AddBeforeCallEnteredCallback.
+   */
+  void RemoveBeforeCallEnteredCallback(BeforeCallEnteredCallback callback);
+
+  /**
+   * Adds a callback to notify the host application when a script finished
+   * running.  If a script re-enters the runtime during executing, the
+   * CallCompletedCallback is only invoked when the outer-most script
+   * execution ends.  Executing scripts inside the callback do not trigger
+   * further callbacks.
+   */
+  void AddCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void AddCallCompletedCallback(DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Removes callback that was installed by AddCallCompletedCallback.
+   */
+  void RemoveCallCompletedCallback(CallCompletedCallback callback);
+  V8_DEPRECATE_SOON(
+      "Use callback with parameter",
+      void RemoveCallCompletedCallback(
+          DeprecatedCallCompletedCallback callback));
+
+  /**
+   * Experimental: Set the PromiseHook callback for various promise
+   * lifecycle events.
+   */
+  void SetPromiseHook(PromiseHook hook);
+
+  /**
+   * Set callback to notify about promise reject with no handler, or
+   * revocation of such a previous notification once the handler is added.
+   */
+  void SetPromiseRejectCallback(PromiseRejectCallback callback);
+
+  /**
+   * Experimental: Runs the Microtask Work Queue until empty
+   * Any exceptions thrown by microtask callbacks are swallowed.
+   */
+  void RunMicrotasks();
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(Local<Function> microtask);
+
+  /**
+   * Experimental: Enqueues the callback to the Microtask Work Queue
+   */
+  void EnqueueMicrotask(MicrotaskCallback microtask, void* data = NULL);
+
+  /**
+   * Experimental: Controls how Microtasks are invoked. See MicrotasksPolicy
+   * for details.
+   */
+  void SetMicrotasksPolicy(MicrotasksPolicy policy);
+  V8_DEPRECATE_SOON("Use SetMicrotasksPolicy",
+                    void SetAutorunMicrotasks(bool autorun));
+
+  /**
+   * Experimental: Returns the policy controlling how Microtasks are invoked.
+   */
+  MicrotasksPolicy GetMicrotasksPolicy() const;
+  V8_DEPRECATE_SOON("Use GetMicrotasksPolicy",
+                    bool WillAutorunMicrotasks() const);
+
+  /**
+   * Experimental: adds a callback to notify the host application after
+   * microtasks were run. The callback is triggered by explicit RunMicrotasks
+   * call or automatic microtasks execution (see SetAutorunMicrotasks).
+   *
+   * Callback will trigger even if microtasks were attempted to run,
+   * but the microtasks queue was empty and no single microtask was actually
+   * executed.
+   *
+   * Executing scriptsinside the callback will not re-trigger microtasks and
+   * the callback.
+   */
+  void AddMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Removes callback that was installed by AddMicrotasksCompletedCallback.
+   */
+  void RemoveMicrotasksCompletedCallback(MicrotasksCompletedCallback callback);
+
+  /**
+   * Sets a callback for counting the number of times a feature of V8 is used.
+   */
+  void SetUseCounterCallback(UseCounterCallback callback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * statistics counters.
+   */
+  void SetCounterFunction(CounterLookupCallback);
+
+  /**
+   * Enables the host application to provide a mechanism for recording
+   * histograms. The CreateHistogram function returns a
+   * histogram which will later be passed to the AddHistogramSample
+   * function.
+   */
+  void SetCreateHistogramFunction(CreateHistogramCallback);
+  void SetAddHistogramSampleFunction(AddHistogramSampleCallback);
+
+  /**
+   * Optional notification that the embedder is idle.
+   * V8 uses the notification to perform garbage collection.
+   * This call can be used repeatedly if the embedder remains idle.
+   * Returns true if the embedder should stop calling IdleNotificationDeadline
+   * until real work has been done.  This indicates that V8 has done
+   * as much cleanup as it will be able to do.
+   *
+   * The deadline_in_seconds argument specifies the deadline V8 has to finish
+   * garbage collection work. deadline_in_seconds is compared with
+   * MonotonicallyIncreasingTime() and should be based on the same timebase as
+   * that function. There is no guarantee that the actual work will be done
+   * within the time limit.
+   */
+  bool IdleNotificationDeadline(double deadline_in_seconds);
+
+  V8_DEPRECATED("use IdleNotificationDeadline()",
+                bool IdleNotification(int idle_time_in_ms));
+
+  /**
+   * Optional notification that the system is running low on memory.
+   * V8 uses these notifications to attempt to free memory.
+   */
+  void LowMemoryNotification();
+
+  /**
+   * Optional notification that a context has been disposed. V8 uses
+   * these notifications to guide the GC heuristic. Returns the number
+   * of context disposals - including this one - since the last time
+   * V8 had a chance to clean up.
+   *
+   * The optional parameter |dependant_context| specifies whether the disposed
+   * context was depending on state from other contexts or not.
+   */
+  int ContextDisposedNotification(bool dependant_context = true);
+
+  /**
+   * Optional notification that the isolate switched to the foreground.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInForegroundNotification();
+
+  /**
+   * Optional notification that the isolate switched to the background.
+   * V8 uses these notifications to guide heuristics.
+   */
+  void IsolateInBackgroundNotification();
+
+  /**
+   * Optional notification to tell V8 the current performance requirements
+   * of the embedder based on RAIL.
+   * V8 uses these notifications to guide heuristics.
+   * This is an unfinished experimental feature. Semantics and implementation
+   * may change frequently.
+   */
+  void SetRAILMode(RAILMode rail_mode);
+
+  /**
+   * Optional notification to tell V8 the current isolate is used for debugging
+   * and requires higher heap limit.
+   */
+  void IncreaseHeapLimitForDebugging();
+
+  /**
+   * Restores the original heap limit after IncreaseHeapLimitForDebugging().
+   */
+  void RestoreOriginalHeapLimit();
+
+  /**
+   * Returns true if the heap limit was increased for debugging and the
+   * original heap limit was not restored yet.
+   */
+  bool IsHeapLimitIncreasedForDebugging();
+
+  /**
+   * Allows the host application to provide the address of a function that is
+   * notified each time code is added, moved or removed.
+   *
+   * \param options options for the JIT code event handler.
+   * \param event_handler the JIT code event handler, which will be invoked
+   *     each time code is added, moved or removed.
+   * \note \p event_handler won't get notified of existent code.
+   * \note since code removal notifications are not currently issued, the
+   *     \p event_handler may get notifications of code that overlaps earlier
+   *     code notifications. This happens when code areas are reused, and the
+   *     earlier overlapping code areas should therefore be discarded.
+   * \note the events passed to \p event_handler and the strings they point to
+   *     are not guaranteed to live past each call. The \p event_handler must
+   *     copy strings and other parameters it needs to keep around.
+   * \note the set of events declared in JitCodeEvent::EventType is expected to
+   *     grow over time, and the JitCodeEvent structure is expected to accrue
+   *     new members. The \p event_handler function must ignore event codes
+   *     it does not recognize to maintain future compatibility.
+   * \note Use Isolate::CreateParams to get events for code executed during
+   *     Isolate setup.
+   */
+  void SetJitCodeEventHandler(JitCodeEventOptions options,
+                              JitCodeEventHandler event_handler);
+
+  /**
+   * Modifies the stack limit for this Isolate.
+   *
+   * \param stack_limit An address beyond which the Vm's stack may not grow.
+   *
+   * \note  If you are using threads then you should hold the V8::Locker lock
+   *     while setting the stack limit and you must set a non-default stack
+   *     limit separately for each thread.
+   */
+  void SetStackLimit(uintptr_t stack_limit);
+
+  /**
+   * Returns a memory range that can potentially contain jitted code.
+   *
+   * On Win64, embedders are advised to install function table callbacks for
+   * these ranges, as default SEH won't be able to unwind through jitted code.
+   *
+   * The first page of the code range is reserved for the embedder and is
+   * committed, writable, and executable.
+   *
+   * Might be empty on other platforms.
+   *
+   * https://code.google.com/p/v8/issues/detail?id=3598
+   */
+  void GetCodeRange(void** start, size_t* length_in_bytes);
+
+  /** Set the callback to invoke in case of fatal errors. */
+  void SetFatalErrorHandler(FatalErrorCallback that);
+
+  /** Set the callback to invoke in case of OOM errors. */
+  void SetOOMErrorHandler(OOMErrorCallback that);
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  void SetAllowCodeGenerationFromStringsCallback(
+      AllowCodeGenerationFromStringsCallback callback);
+
+  /**
+   * Embedder over{ride|load} injection points for wasm APIs.
+   */
+  void SetWasmModuleCallback(ExtensionCallback callback);
+  void SetWasmCompileCallback(ExtensionCallback callback);
+  void SetWasmInstanceCallback(ExtensionCallback callback);
+  void SetWasmInstantiateCallback(ExtensionCallback callback);
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  bool IsDead();
+
+  /**
+   * Adds a message listener (errors only).
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  bool AddMessageListener(MessageCallback that,
+                          Local<Value> data = Local<Value>());
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   *
+   * A listener can listen for particular error levels by providing a mask.
+   */
+  bool AddMessageListenerWithErrorLevel(MessageCallback that,
+                                        int message_levels,
+                                        Local<Value> data = Local<Value>());
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  void RemoveMessageListeners(MessageCallback that);
+
+  /** Callback function for reporting failed access checks.*/
+  void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback);
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  void SetCaptureStackTraceForUncaughtExceptions(
+      bool capture, int frame_limit = 10,
+      StackTrace::StackTraceOptions options = StackTrace::kOverview);
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  void VisitExternalResources(ExternalResourceVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  void VisitHandlesForPartialDependence(PersistentHandleVisitor* visitor);
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are weak to be marked as inactive if there is no
+   * pending activity for the handle.
+   */
+  void VisitWeakHandles(PersistentHandleVisitor* visitor);
+
+  /**
+   * Check if this isolate is in use.
+   * True if at least one thread Enter'ed this isolate.
+   */
+  bool IsInUse();
+
+  /**
+   * Set whether calling Atomics.wait (a function that may block) is allowed in
+   * this isolate. This can also be configured via
+   * CreateParams::allow_atomics_wait.
+   */
+  void SetAllowAtomicsWait(bool allow);
+
+  Isolate() = delete;
+  ~Isolate() = delete;
+  Isolate(const Isolate&) = delete;
+  Isolate& operator=(const Isolate&) = delete;
+  void* operator new(size_t size) = delete;
+  void operator delete(void*, size_t) = delete;
+
+ private:
+  template <class K, class V, class Traits>
+  friend class PersistentValueMapBase;
+
+  void ReportExternalAllocationLimitReached();
+};
+
+class V8_EXPORT StartupData {
+ public:
+  const char* data;
+  int raw_size;
+};
+
+
+/**
+ * EntropySource is used as a callback function when v8 needs a source
+ * of entropy.
+ */
+typedef bool (*EntropySource)(unsigned char* buffer, size_t length);
+
+/**
+ * ReturnAddressLocationResolver is used as a callback function when v8 is
+ * resolving the location of a return address on the stack. Profilers that
+ * change the return address on the stack can use this to resolve the stack
+ * location to whereever the profiler stashed the original return address.
+ *
+ * \param return_addr_location A location on stack where a machine
+ *    return address resides.
+ * \returns Either return_addr_location, or else a pointer to the profiler's
+ *    copy of the original return address.
+ *
+ * \note The resolver function must not cause garbage collection.
+ */
+typedef uintptr_t (*ReturnAddressLocationResolver)(
+    uintptr_t return_addr_location);
+
+
+/**
+ * Container class for static utility functions.
+ */
+class V8_EXPORT V8 {
+ public:
+  /** Set the callback to invoke in case of fatal errors. */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFatalErrorHandler(FatalErrorCallback that));
+
+  /**
+   * Set the callback to invoke to check if code generation from
+   * strings should be allowed.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void SetAllowCodeGenerationFromStringsCallback(
+                                 AllowCodeGenerationFromStringsCallback that));
+
+  /**
+  * Check if V8 is dead and therefore unusable.  This is the case after
+  * fatal errors such as out-of-memory situations.
+  */
+  V8_INLINE static V8_DEPRECATED("Use isolate version", bool IsDead());
+
+  /**
+   * Hand startup data to V8, in case the embedder has chosen to build
+   * V8 with external startup data.
+   *
+   * Note:
+   * - By default the startup data is linked into the V8 library, in which
+   *   case this function is not meaningful.
+   * - If this needs to be called, it needs to be called before V8
+   *   tries to make use of its built-ins.
+   * - To avoid unnecessary copies of data, V8 will point directly into the
+   *   given data blob, so pretty please keep it around until V8 exit.
+   * - Compression of the startup blob might be useful, but needs to
+   *   handled entirely on the embedders' side.
+   * - The call will abort if the data is invalid.
+   */
+  static void SetNativesDataBlob(StartupData* startup_blob);
+  static void SetSnapshotDataBlob(StartupData* startup_blob);
+
+  /**
+   * Bootstrap an isolate and a context from scratch to create a startup
+   * snapshot. Include the side-effects of running the optional script.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   */
+  static StartupData CreateSnapshotDataBlob(const char* embedded_source = NULL);
+
+  /**
+   * Bootstrap an isolate and a context from the cold startup blob, run the
+   * warm-up script to trigger code compilation. The side effects are then
+   * discarded. The resulting startup snapshot will include compiled code.
+   * Returns { NULL, 0 } on failure.
+   * The caller acquires ownership of the data array in the return value.
+   * The argument startup blob is untouched.
+   */
+  static StartupData WarmUpSnapshotDataBlob(StartupData cold_startup_blob,
+                                            const char* warmup_source);
+
+  /**
+   * Adds a message listener.
+   *
+   * The same message listener can be added more than once and in that
+   * case it will be called more than once for each message.
+   *
+   * If data is specified, it will be passed to the callback when it is called.
+   * Otherwise, the exception object will be passed to the callback instead.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool AddMessageListener(MessageCallback that,
+                              Local<Value> data = Local<Value>()));
+
+  /**
+   * Remove all message listeners from the specified callback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void RemoveMessageListeners(MessageCallback that));
+
+  /**
+   * Tells V8 to capture current stack trace when uncaught exception occurs
+   * and report it to the message listeners. The option is off by default.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetCaptureStackTraceForUncaughtExceptions(
+          bool capture, int frame_limit = 10,
+          StackTrace::StackTraceOptions options = StackTrace::kOverview));
+
+  /**
+   * Sets V8 flags from a string.
+   */
+  static void SetFlagsFromString(const char* str, int length);
+
+  /**
+   * Sets V8 flags from the command line.
+   */
+  static void SetFlagsFromCommandLine(int* argc,
+                                      char** argv,
+                                      bool remove_flags);
+
+  /** Get the version string. */
+  static const char* GetVersion();
+
+  /** Callback function for reporting failed access checks.*/
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback));
+
+  /**
+   * Enables the host application to receive a notification before a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCPrologueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCPrologueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCPrologueCallback(GCCallback callback));
+
+  /**
+   * Enables the host application to receive a notification after a
+   * garbage collection.  Allocations are not allowed in the
+   * callback function, you therefore cannot manipulate objects (set
+   * or delete properties for example) since it is possible such
+   * operations will result in the allocation of objects. It is possible
+   * to specify the GCType filter for your callback. But it is not possible to
+   * register the same callback function two times with different
+   * GCType filters.
+   */
+  static V8_DEPRECATED(
+      "Use isolate version",
+      void AddGCEpilogueCallback(GCCallback callback,
+                                 GCType gc_type_filter = kGCTypeAll));
+
+  /**
+   * This function removes callback which was installed by
+   * AddGCEpilogueCallback function.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void RemoveGCEpilogueCallback(GCCallback callback));
+
+  /**
+   * Initializes V8. This function needs to be called before the first Isolate
+   * is created. It always returns true.
+   */
+  static bool Initialize();
+
+  /**
+   * Allows the host application to provide a callback which can be used
+   * as a source of entropy for random number generators.
+   */
+  static void SetEntropySource(EntropySource source);
+
+  /**
+   * Allows the host application to provide a callback that allows v8 to
+   * cooperate with a profiler that rewrites return addresses on stack.
+   */
+  static void SetReturnAddressLocationResolver(
+      ReturnAddressLocationResolver return_address_resolver);
+
+  /**
+   * Forcefully terminate the current thread of JavaScript execution
+   * in the given isolate.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to terminate the current JS execution.
+   */
+  V8_INLINE static V8_DEPRECATED("Use isolate version",
+                                 void TerminateExecution(Isolate* isolate));
+
+  /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   *
+   * \param isolate The isolate in which to check.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      bool IsExecutionTerminating(Isolate* isolate = NULL));
+
+  /**
+   * Resume execution capability in the given isolate, whose execution
+   * was previously forcefully terminated using TerminateExecution().
+   *
+   * When execution is forcefully terminated using TerminateExecution(),
+   * the isolate can not resume execution until all JavaScript frames
+   * have propagated the uncatchable exception which is generated.  This
+   * method allows the program embedding the engine to handle the
+   * termination event and resume execution capability, even if
+   * JavaScript frames remain on the stack.
+   *
+   * This method can be used by any thread even if that thread has not
+   * acquired the V8 lock with a Locker object.
+   *
+   * \param isolate The isolate in which to resume execution capability.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version", void CancelTerminateExecution(Isolate* isolate));
+
+  /**
+   * Releases any resources used by v8 and stops any utility threads
+   * that may be running.  Note that disposing v8 is permanent, it
+   * cannot be reinitialized.
+   *
+   * It should generally not be necessary to dispose v8 before exiting
+   * a process, this should happen automatically.  It is only necessary
+   * to use if the process needs the resources taken up by v8.
+   */
+  static bool Dispose();
+
+  /**
+   * Iterates through all external resources referenced from current isolate
+   * heap.  GC is not invoked prior to iterating, therefore there is no
+   * guarantee that visited objects are still alive.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitExternalResources(ExternalResourceVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in isolate's heap that have
+   * class_ids.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesWithClassIds(Isolate* isolate,
+                                    PersistentHandleVisitor* visitor));
+
+  /**
+   * Iterates through all the persistent handles in the current isolate's heap
+   * that have class_ids and are candidates to be marked as partially dependent
+   * handles. This will visit handles to young objects created since the last
+   * garbage collection but is free to visit an arbitrary superset of these
+   * objects.
+   */
+  V8_INLINE static V8_DEPRECATED(
+      "Use isolate version",
+      void VisitHandlesForPartialDependence(Isolate* isolate,
+                                            PersistentHandleVisitor* visitor));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. Returns true on success.
+   *
+   * If V8 was compiled with the ICU data in an external file, the location
+   * of the data file has to be provided.
+   */
+  V8_DEPRECATE_SOON(
+      "Use version with default location.",
+      static bool InitializeICU(const char* icu_data_file = nullptr));
+
+  /**
+   * Initialize the ICU library bundled with V8. The embedder should only
+   * invoke this method when using the bundled ICU. If V8 was compiled with
+   * the ICU data in an external file and when the default location of that
+   * file should be used, a path to the executable must be provided.
+   * Returns true on success.
+   *
+   * The default is a file called icudtl.dat side-by-side with the executable.
+   *
+   * Optionally, the location of the data file can be provided to override the
+   * default.
+   */
+  static bool InitializeICUDefaultLocation(const char* exec_path,
+                                           const char* icu_data_file = nullptr);
+
+  /**
+   * Initialize the external startup data. The embedder only needs to
+   * invoke this method when external startup data was enabled in a build.
+   *
+   * If V8 was compiled with the startup data in an external file, then
+   * V8 needs to be given those external files during startup. There are
+   * three ways to do this:
+   * - InitializeExternalStartupData(const char*)
+   *   This will look in the given directory for files "natives_blob.bin"
+   *   and "snapshot_blob.bin" - which is what the default build calls them.
+   * - InitializeExternalStartupData(const char*, const char*)
+   *   As above, but will directly use the two given file names.
+   * - Call SetNativesDataBlob, SetNativesDataBlob.
+   *   This will read the blobs from the given data structures and will
+   *   not perform any file IO.
+   */
+  static void InitializeExternalStartupData(const char* directory_path);
+  static void InitializeExternalStartupData(const char* natives_blob,
+                                            const char* snapshot_blob);
+  /**
+   * Sets the v8::Platform to use. This should be invoked before V8 is
+   * initialized.
+   */
+  static void InitializePlatform(Platform* platform);
+
+  /**
+   * Clears all references to the v8::Platform. This should be invoked after
+   * V8 was disposed.
+   */
+  static void ShutdownPlatform();
+
+#if V8_OS_LINUX && V8_TARGET_ARCH_X64 && !V8_OS_ANDROID
+  /**
+   * Give the V8 signal handler a chance to handle a fault.
+   *
+   * This function determines whether a memory access violation can be recovered
+   * by V8. If so, it will return true and modify context to return to a code
+   * fragment that can recover from the fault. Otherwise, TryHandleSignal will
+   * return false.
+   *
+   * The parameters to this function correspond to those passed to a Linux
+   * signal handler.
+   *
+   * \param signal_number The signal number.
+   *
+   * \param info A pointer to the siginfo_t structure provided to the signal
+   * handler.
+   *
+   * \param context The third argument passed to the Linux signal handler, which
+   * points to a ucontext_t structure.
+   */
+  static bool TryHandleSignal(int signal_number, void* info, void* context);
+#endif  // V8_OS_LINUX
+
+  /**
+   * Enable the default signal handler rather than using one provided by the
+   * embedder.
+   */
+  static bool RegisterDefaultSignalHandler();
+
+ private:
+  V8();
+
+  static internal::Object** GlobalizeReference(internal::Isolate* isolate,
+                                               internal::Object** handle);
+  static internal::Object** CopyPersistent(internal::Object** handle);
+  static void DisposeGlobal(internal::Object** global_handle);
+  static void MakeWeak(internal::Object** location, void* data,
+                       WeakCallbackInfo<void>::Callback weak_callback,
+                       WeakCallbackType type);
+  static void MakeWeak(internal::Object** location, void* data,
+                       // Must be 0 or -1.
+                       int internal_field_index1,
+                       // Must be 1 or -1.
+                       int internal_field_index2,
+                       WeakCallbackInfo<void>::Callback weak_callback);
+  static void MakeWeak(internal::Object*** location_addr);
+  static void* ClearWeak(internal::Object** location);
+  static Value* Eternalize(Isolate* isolate, Value* handle);
+
+  static void RegisterExternallyReferencedObject(internal::Object** object,
+                                                 internal::Isolate* isolate);
+
+  template <class K, class V, class T>
+  friend class PersistentValueMapBase;
+
+  static void FromJustIsNothing();
+  static void ToLocalEmpty();
+  static void InternalFieldOutOfBounds(int index);
+  template <class T> friend class Local;
+  template <class T>
+  friend class MaybeLocal;
+  template <class T>
+  friend class Maybe;
+  template <class T>
+  friend class WeakCallbackInfo;
+  template <class T> friend class Eternal;
+  template <class T> friend class PersistentBase;
+  template <class T, class M> friend class Persistent;
+  friend class Context;
+};
+
+/**
+ * Helper class to create a snapshot data blob.
+ */
+class V8_EXPORT SnapshotCreator {
+ public:
+  enum class FunctionCodeHandling { kClear, kKeep };
+
+  /**
+   * Create and enter an isolate, and set it up for serialization.
+   * The isolate is either created from scratch or from an existing snapshot.
+   * The caller keeps ownership of the argument snapshot.
+   * \param existing_blob existing snapshot from which to create this one.
+   * \param external_references a null-terminated array of external references
+   *        that must be equivalent to CreateParams::external_references.
+   */
+  SnapshotCreator(intptr_t* external_references = nullptr,
+                  StartupData* existing_blob = nullptr);
+
+  ~SnapshotCreator();
+
+  /**
+   * \returns the isolate prepared by the snapshot creator.
+   */
+  Isolate* GetIsolate();
+
+  /**
+   * Set the default context to be included in the snapshot blob.
+   * The snapshot will not contain the global proxy, and we expect one or a
+   * global object template to create one, to be provided upon deserialization.
+   */
+  void SetDefaultContext(Local<Context> context);
+
+  /**
+   * Add additional context to be included in the snapshot blob.
+   * The snapshot will include the global proxy.
+   *
+   * \param callback optional callback to serialize internal fields.
+   *
+   * \returns the index of the context in the snapshot blob.
+   */
+  size_t AddContext(Local<Context> context,
+                    SerializeInternalFieldsCallback callback =
+                        SerializeInternalFieldsCallback());
+
+  /**
+   * Add a template to be included in the snapshot blob.
+   * \returns the index of the template in the snapshot blob.
+   */
+  size_t AddTemplate(Local<Template> template_obj);
+
+  /**
+   * Created a snapshot data blob.
+   * This must not be called from within a handle scope.
+   * \param function_code_handling whether to include compiled function code
+   *        in the snapshot.
+   * \returns { nullptr, 0 } on failure, and a startup snapshot on success. The
+   *        caller acquires ownership of the data array in the return value.
+   */
+  StartupData CreateBlob(FunctionCodeHandling function_code_handling);
+
+  // Disallow copying and assigning.
+  SnapshotCreator(const SnapshotCreator&) = delete;
+  void operator=(const SnapshotCreator&) = delete;
+
+ private:
+  void* data_;
+};
+
+/**
+ * A simple Maybe type, representing an object which may or may not have a
+ * value, see https://hackage.haskell.org/package/base/docs/Data-Maybe.html.
+ *
+ * If an API method returns a Maybe<>, the API method can potentially fail
+ * either because an exception is thrown, or because an exception is pending,
+ * e.g. because a previous API call threw an exception that hasn't been caught
+ * yet, or because a TerminateExecution exception was thrown. In that case, a
+ * "Nothing" value is returned.
+ */
+template <class T>
+class Maybe {
+ public:
+  V8_INLINE bool IsNothing() const { return !has_value_; }
+  V8_INLINE bool IsJust() const { return has_value_; }
+
+  /**
+   * An alias for |FromJust|. Will crash if the Maybe<> is nothing.
+   */
+  V8_INLINE T ToChecked() const { return FromJust(); }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), |false| is returned and |out| is left untouched.
+   */
+  V8_WARN_UNUSED_RESULT V8_INLINE bool To(T* out) const {
+    if (V8_LIKELY(IsJust())) *out = value_;
+    return IsJust();
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T. If this Maybe<> is
+   * nothing (empty), V8 will crash the process.
+   */
+  V8_INLINE T FromJust() const {
+    if (V8_UNLIKELY(!IsJust())) V8::FromJustIsNothing();
+    return value_;
+  }
+
+  /**
+   * Converts this Maybe<> to a value of type T, using a default value if this
+   * Maybe<> is nothing (empty).
+   */
+  V8_INLINE T FromMaybe(const T& default_value) const {
+    return has_value_ ? value_ : default_value;
+  }
+
+  V8_INLINE bool operator==(const Maybe& other) const {
+    return (IsJust() == other.IsJust()) &&
+           (!IsJust() || FromJust() == other.FromJust());
+  }
+
+  V8_INLINE bool operator!=(const Maybe& other) const {
+    return !operator==(other);
+  }
+
+ private:
+  Maybe() : has_value_(false) {}
+  explicit Maybe(const T& t) : has_value_(true), value_(t) {}
+
+  bool has_value_;
+  T value_;
+
+  template <class U>
+  friend Maybe<U> Nothing();
+  template <class U>
+  friend Maybe<U> Just(const U& u);
+};
+
+
+template <class T>
+inline Maybe<T> Nothing() {
+  return Maybe<T>();
+}
+
+
+template <class T>
+inline Maybe<T> Just(const T& t) {
+  return Maybe<T>(t);
+}
+
+
+/**
+ * An external exception handler.
+ */
+class V8_EXPORT TryCatch {
+ public:
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  V8_DEPRECATED("Use isolate version", TryCatch());
+
+  /**
+   * Creates a new try/catch block and registers it with v8.  Note that
+   * all TryCatch blocks should be stack allocated because the memory
+   * location itself is compared against JavaScript try/catch blocks.
+   */
+  TryCatch(Isolate* isolate);
+
+  /**
+   * Unregisters and deletes this try/catch block.
+   */
+  ~TryCatch();
+
+  /**
+   * Returns true if an exception has been caught by this try/catch block.
+   */
+  bool HasCaught() const;
+
+  /**
+   * For certain types of exceptions, it makes no sense to continue execution.
+   *
+   * If CanContinue returns false, the correct action is to perform any C++
+   * cleanup needed and then return.  If CanContinue returns false and
+   * HasTerminated returns true, it is possible to call
+   * CancelTerminateExecution in order to continue calling into the engine.
+   */
+  bool CanContinue() const;
+
+  /**
+   * Returns true if an exception has been caught due to script execution
+   * being terminated.
+   *
+   * There is no JavaScript representation of an execution termination
+   * exception.  Such exceptions are thrown when the TerminateExecution
+   * methods are called to terminate a long-running script.
+   *
+   * If such an exception has been thrown, HasTerminated will return true,
+   * indicating that it is possible to call CancelTerminateExecution in order
+   * to continue calling into the engine.
+   */
+  bool HasTerminated() const;
+
+  /**
+   * Throws the exception caught by this TryCatch in a way that avoids
+   * it being caught again by this same TryCatch.  As with ThrowException
+   * it is illegal to execute any JavaScript operations after calling
+   * ReThrow; the caller must return immediately to where the exception
+   * is caught.
+   */
+  Local<Value> ReThrow();
+
+  /**
+   * Returns the exception caught by this try/catch block.  If no exception has
+   * been caught an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been destroyed.
+   */
+  Local<Value> Exception() const;
+
+  /**
+   * Returns the .stack property of the thrown object.  If no .stack
+   * property is present an empty handle is returned.
+   */
+  V8_DEPRECATE_SOON("Use maybe version.", Local<Value> StackTrace() const);
+  V8_WARN_UNUSED_RESULT MaybeLocal<Value> StackTrace(
+      Local<Context> context) const;
+
+  /**
+   * Returns the message associated with this exception.  If there is
+   * no message associated an empty handle is returned.
+   *
+   * The returned handle is valid until this TryCatch block has been
+   * destroyed.
+   */
+  Local<v8::Message> Message() const;
+
+  /**
+   * Clears any exceptions that may have been caught by this try/catch block.
+   * After this method has been called, HasCaught() will return false. Cancels
+   * the scheduled exception if it is caught and ReThrow() is not called before.
+   *
+   * It is not necessary to clear a try/catch block before using it again; if
+   * another exception is thrown the previously caught exception will just be
+   * overwritten.  However, it is often a good idea since it makes it easier
+   * to determine which operation threw a given exception.
+   */
+  void Reset();
+
+  /**
+   * Set verbosity of the external exception handler.
+   *
+   * By default, exceptions that are caught by an external exception
+   * handler are not reported.  Call SetVerbose with true on an
+   * external exception handler to have exceptions caught by the
+   * handler reported as if they were not caught.
+   */
+  void SetVerbose(bool value);
+
+  /**
+   * Returns true if verbosity is enabled.
+   */
+  bool IsVerbose() const;
+
+  /**
+   * Set whether or not this TryCatch should capture a Message object
+   * which holds source information about where the exception
+   * occurred.  True by default.
+   */
+  void SetCaptureMessage(bool value);
+
+  /**
+   * There are cases when the raw address of C++ TryCatch object cannot be
+   * used for comparisons with addresses into the JS stack. The cases are:
+   * 1) ARM, ARM64 and MIPS simulators which have separate JS stack.
+   * 2) Address sanitizer allocates local C++ object in the heap when
+   *    UseAfterReturn mode is enabled.
+   * This method returns address that can be used for comparisons with
+   * addresses into the JS stack. When neither simulator nor ASAN's
+   * UseAfterReturn is enabled, then the address returned will be the address
+   * of the C++ try catch handler itself.
+   */
+  static void* JSStackComparableAddress(TryCatch* handler) {
+    if (handler == NULL) return NULL;
+    return handler->js_stack_comparable_address_;
+  }
+
+  TryCatch(const TryCatch&) = delete;
+  void operator=(const TryCatch&) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
+
+ private:
+  void ResetInternal();
+
+  internal::Isolate* isolate_;
+  TryCatch* next_;
+  void* exception_;
+  void* message_obj_;
+  void* js_stack_comparable_address_;
+  bool is_verbose_ : 1;
+  bool can_continue_ : 1;
+  bool capture_message_ : 1;
+  bool rethrow_ : 1;
+  bool has_terminated_ : 1;
+
+  friend class internal::Isolate;
+};
+
+
+// --- Context ---
+
+
+/**
+ * A container for extension names.
+ */
+class V8_EXPORT ExtensionConfiguration {
+ public:
+  ExtensionConfiguration() : name_count_(0), names_(NULL) { }
+  ExtensionConfiguration(int name_count, const char* names[])
+      : name_count_(name_count), names_(names) { }
+
+  const char** begin() const { return &names_[0]; }
+  const char** end()  const { return &names_[name_count_]; }
+
+ private:
+  const int name_count_;
+  const char** names_;
+};
+
+/**
+ * A sandboxed execution context with its own set of built-in objects
+ * and functions.
+ */
+class V8_EXPORT Context {
+ public:
+  /**
+   * Returns the global proxy object.
+   *
+   * Global proxy object is a thin wrapper whose prototype points to actual
+   * context's global object with the properties like Object, etc. This is done
+   * that way for security reasons (for more details see
+   * https://wiki.mozilla.org/Gecko:SplitWindow).
+   *
+   * Please note that changes to global proxy object prototype most probably
+   * would break VM---v8 expects only global object as a prototype of global
+   * proxy object.
+   */
+  Local<Object> Global();
+
+  /**
+   * Detaches the global object from its context before
+   * the global object can be reused to create a new context.
+   */
+  void DetachGlobal();
+
+  /**
+   * Creates a new context and returns a handle to the newly allocated
+   * context.
+   *
+   * \param isolate The isolate in which to create the context.
+   *
+   * \param extensions An optional extension configuration containing
+   * the extensions to be installed in the newly created context.
+   *
+   * \param global_template An optional object template from which the
+   * global object for the newly created context will be created.
+   *
+   * \param global_object An optional global object to be reused for
+   * the newly created context. This global object must have been
+   * created by a previous call to Context::New with the same global
+   * template. The state of the global object will be completely reset
+   * and only object identify will remain.
+   */
+  static Local<Context> New(
+      Isolate* isolate, ExtensionConfiguration* extensions = NULL,
+      MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Create a new context from a (non-default) context snapshot. There
+   * is no way to provide a global object template since we do not create
+   * a new global object from template, but we can reuse a global object.
+   *
+   * \param isolate See v8::Context::New.
+   *
+   * \param context_snapshot_index The index of the context snapshot to
+   * deserialize from. Use v8::Context::New for the default snapshot.
+   *
+   * \param embedder_fields_deserializer Optional callback to deserialize
+   * internal fields. It should match the SerializeInternalFieldCallback used
+   * to serialize.
+   *
+   * \param extensions See v8::Context::New.
+   *
+   * \param global_object See v8::Context::New.
+   */
+
+  static MaybeLocal<Context> FromSnapshot(
+      Isolate* isolate, size_t context_snapshot_index,
+      DeserializeInternalFieldsCallback embedder_fields_deserializer =
+          DeserializeInternalFieldsCallback(),
+      ExtensionConfiguration* extensions = nullptr,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Returns an global object that isn't backed by an actual context.
+   *
+   * The global template needs to have access checks with handlers installed.
+   * If an existing global object is passed in, the global object is detached
+   * from its context.
+   *
+   * Note that this is different from a detached context where all accesses to
+   * the global proxy will fail. Instead, the access check handlers are invoked.
+   *
+   * It is also not possible to detach an object returned by this method.
+   * Instead, the access check handlers need to return nothing to achieve the
+   * same effect.
+   *
+   * It is possible, however, to create a new context from the global object
+   * returned by this method.
+   */
+  static MaybeLocal<Object> NewRemoteContext(
+      Isolate* isolate, Local<ObjectTemplate> global_template,
+      MaybeLocal<Value> global_object = MaybeLocal<Value>());
+
+  /**
+   * Sets the security token for the context.  To access an object in
+   * another context, the security tokens must match.
+   */
+  void SetSecurityToken(Local<Value> token);
+
+  /** Restores the security token to the default value. */
+  void UseDefaultSecurityToken();
+
+  /** Returns the security token of this context.*/
+  Local<Value> GetSecurityToken();
+
+  /**
+   * Enter this context.  After entering a context, all code compiled
+   * and run is compiled and run in this context.  If another context
+   * is already entered, this old context is saved so it can be
+   * restored when the new context is exited.
+   */
+  void Enter();
+
+  /**
+   * Exit this context.  Exiting the current context restores the
+   * context that was in place when entering the current context.
+   */
+  void Exit();
+
+  /** Returns an isolate associated with a current context. */
+  Isolate* GetIsolate();
+
+  /**
+   * The field at kDebugIdIndex used to be reserved for the inspector.
+   * It now serves no purpose.
+   */
+  enum EmbedderDataFields { kDebugIdIndex = 0 };
+
+  /**
+   * Gets the embedder data with the given index, which must have been set by a
+   * previous call to SetEmbedderData with the same index.
+   */
+  V8_INLINE Local<Value> GetEmbedderData(int index);
+
+  /**
+   * Gets the binding object used by V8 extras. Extra natives get a reference
+   * to this object and can use it to "export" functionality by adding
+   * properties. Extra natives can also "import" functionality by accessing
+   * properties added by the embedder using the V8 API.
+   */
+  Local<Object> GetExtrasBindingObject();
+
+  /**
+   * Sets the embedder data with the given index, growing the data as
+   * needed. Note that index 0 currently has a special meaning for Chrome's
+   * debugger.
+   */
+  void SetEmbedderData(int index, Local<Value> value);
+
+  /**
+   * Gets a 2-byte-aligned native pointer from the embedder data with the given
+   * index, which must have been set by a previous call to
+   * SetAlignedPointerInEmbedderData with the same index. Note that index 0
+   * currently has a special meaning for Chrome's debugger.
+   */
+  V8_INLINE void* GetAlignedPointerFromEmbedderData(int index);
+
+  /**
+   * Sets a 2-byte-aligned native pointer in the embedder data with the given
+   * index, growing the data as needed. Note that index 0 currently has a
+   * special meaning for Chrome's debugger.
+   */
+  void SetAlignedPointerInEmbedderData(int index, void* value);
+
+  /**
+   * Control whether code generation from strings is allowed. Calling
+   * this method with false will disable 'eval' and the 'Function'
+   * constructor for code running in this context. If 'eval' or the
+   * 'Function' constructor are used an exception will be thrown.
+   *
+   * If code generation from strings is not allowed the
+   * V8::AllowCodeGenerationFromStrings callback will be invoked if
+   * set before blocking the call to 'eval' or the 'Function'
+   * constructor. If that callback returns true, the call will be
+   * allowed, otherwise an exception will be thrown. If no callback is
+   * set an exception will be thrown.
+   */
+  void AllowCodeGenerationFromStrings(bool allow);
+
+  /**
+   * Returns true if code generation from strings is allowed for the context.
+   * For more details see AllowCodeGenerationFromStrings(bool) documentation.
+   */
+  bool IsCodeGenerationFromStringsAllowed();
+
+  /**
+   * Sets the error description for the exception that is thrown when
+   * code generation from strings is not allowed and 'eval' or the 'Function'
+   * constructor are called.
+   */
+  void SetErrorMessageForCodeGenerationFromStrings(Local<String> message);
+
+  /**
+   * Estimate the memory in bytes retained by this context.
+   */
+  V8_DEPRECATED("no longer supported", size_t EstimatedSize());
+
+  /**
+   * Stack-allocated class which sets the execution context for all
+   * operations executed within a local scope.
+   */
+  class Scope {
+   public:
+    explicit V8_INLINE Scope(Local<Context> context) : context_(context) {
+      context_->Enter();
+    }
+    V8_INLINE ~Scope() { context_->Exit(); }
+
+   private:
+    Local<Context> context_;
+  };
+
+ private:
+  friend class Value;
+  friend class Script;
+  friend class Object;
+  friend class Function;
+
+  Local<Value> SlowGetEmbedderData(int index);
+  void* SlowGetAlignedPointerFromEmbedderData(int index);
+};
+
+
+/**
+ * Multiple threads in V8 are allowed, but only one thread at a time is allowed
+ * to use any given V8 isolate, see the comments in the Isolate class. The
+ * definition of 'using a V8 isolate' includes accessing handles or holding onto
+ * object pointers obtained from V8 handles while in the particular V8 isolate.
+ * It is up to the user of V8 to ensure, perhaps with locking, that this
+ * constraint is not violated. In addition to any other synchronization
+ * mechanism that may be used, the v8::Locker and v8::Unlocker classes must be
+ * used to signal thread switches to V8.
+ *
+ * v8::Locker is a scoped lock object. While it's active, i.e. between its
+ * construction and destruction, the current thread is allowed to use the locked
+ * isolate. V8 guarantees that an isolate can be locked by at most one thread at
+ * any time. In other words, the scope of a v8::Locker is a critical section.
+ *
+ * Sample usage:
+* \code
+ * ...
+ * {
+ *   v8::Locker locker(isolate);
+ *   v8::Isolate::Scope isolate_scope(isolate);
+ *   ...
+ *   // Code using V8 and isolate goes here.
+ *   ...
+ * } // Destructor called here
+ * \endcode
+ *
+ * If you wish to stop using V8 in a thread A you can do this either by
+ * destroying the v8::Locker object as above or by constructing a v8::Unlocker
+ * object:
+ *
+ * \code
+ * {
+ *   isolate->Exit();
+ *   v8::Unlocker unlocker(isolate);
+ *   ...
+ *   // Code not using V8 goes here while V8 can run in another thread.
+ *   ...
+ * } // Destructor called here.
+ * isolate->Enter();
+ * \endcode
+ *
+ * The Unlocker object is intended for use in a long-running callback from V8,
+ * where you want to release the V8 lock for other threads to use.
+ *
+ * The v8::Locker is a recursive lock, i.e. you can lock more than once in a
+ * given thread. This can be useful if you have code that can be called either
+ * from code that holds the lock or from code that does not. The Unlocker is
+ * not recursive so you can not have several Unlockers on the stack at once, and
+ * you can not use an Unlocker in a thread that is not inside a Locker's scope.
+ *
+ * An unlocker will unlock several lockers if it has to and reinstate the
+ * correct depth of locking on its destruction, e.g.:
+ *
+ * \code
+ * // V8 not locked.
+ * {
+ *   v8::Locker locker(isolate);
+ *   Isolate::Scope isolate_scope(isolate);
+ *   // V8 locked.
+ *   {
+ *     v8::Locker another_locker(isolate);
+ *     // V8 still locked (2 levels).
+ *     {
+ *       isolate->Exit();
+ *       v8::Unlocker unlocker(isolate);
+ *       // V8 not locked.
+ *     }
+ *     isolate->Enter();
+ *     // V8 locked again (2 levels).
+ *   }
+ *   // V8 still locked (1 level).
+ * }
+ * // V8 Now no longer locked.
+ * \endcode
+ */
+class V8_EXPORT Unlocker {
+ public:
+  /**
+   * Initialize Unlocker for a given Isolate.
+   */
+  V8_INLINE explicit Unlocker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Unlocker();
+ private:
+  void Initialize(Isolate* isolate);
+
+  internal::Isolate* isolate_;
+};
+
+
+class V8_EXPORT Locker {
+ public:
+  /**
+   * Initialize Locker for a given Isolate.
+   */
+  V8_INLINE explicit Locker(Isolate* isolate) { Initialize(isolate); }
+
+  ~Locker();
+
+  /**
+   * Returns whether or not the locker for a given isolate, is locked by the
+   * current thread.
+   */
+  static bool IsLocked(Isolate* isolate);
+
+  /**
+   * Returns whether v8::Locker is being used by this V8 instance.
+   */
+  static bool IsActive();
+
+  // Disallow copying and assigning.
+  Locker(const Locker&) = delete;
+  void operator=(const Locker&) = delete;
+
+ private:
+  void Initialize(Isolate* isolate);
+
+  bool has_lock_;
+  bool top_level_;
+  internal::Isolate* isolate_;
+};
+
+
+// --- Implementation ---
+
+
+namespace internal {
+
+const int kApiPointerSize = sizeof(void*);  // NOLINT
+const int kApiIntSize = sizeof(int);  // NOLINT
+const int kApiInt64Size = sizeof(int64_t);  // NOLINT
+
+// Tag information for HeapObject.
+const int kHeapObjectTag = 1;
+const int kHeapObjectTagSize = 2;
+const intptr_t kHeapObjectTagMask = (1 << kHeapObjectTagSize) - 1;
+
+// Tag information for Smi.
+const int kSmiTag = 0;
+const int kSmiTagSize = 1;
+const intptr_t kSmiTagMask = (1 << kSmiTagSize) - 1;
+
+template <size_t ptr_size> struct SmiTagging;
+
+template<int kSmiShiftSize>
+V8_INLINE internal::Object* IntToSmi(int value) {
+  int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
+  uintptr_t tagged_value =
+      (static_cast<uintptr_t>(value) << smi_shift_bits) | kSmiTag;
+  return reinterpret_cast<internal::Object*>(tagged_value);
+}
+
+// Smi constants for 32-bit systems.
+template <> struct SmiTagging<4> {
+  enum { kSmiShiftSize = 0, kSmiValueSize = 31 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Throw away top 32 bits and shift down (requires >> to be sign extending).
+    return static_cast<int>(reinterpret_cast<intptr_t>(value)) >> shift_bits;
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as an tagged small integer, the two
+    // most-significant bits of 'value' must be either 00 or 11 due to
+    // sign-extension. To check this we add 01 to the two
+    // most-significant bits, and check if the most-significant bit is 0
+    //
+    // CAUTION: The original code below:
+    // bool result = ((value + 0x40000000) & 0x80000000) == 0;
+    // may lead to incorrect results according to the C language spec, and
+    // in fact doesn't work correctly with gcc4.1.1 in some cases: The
+    // compiler may produce undefined results in case of signed integer
+    // overflow. The computation must be done w/ unsigned ints.
+    return static_cast<uintptr_t>(value + 0x40000000U) < 0x80000000U;
+  }
+};
+
+// Smi constants for 64-bit systems.
+template <> struct SmiTagging<8> {
+  enum { kSmiShiftSize = 31, kSmiValueSize = 32 };
+  static int SmiShiftSize() { return kSmiShiftSize; }
+  static int SmiValueSize() { return kSmiValueSize; }
+  V8_INLINE static int SmiToInt(const internal::Object* value) {
+    int shift_bits = kSmiTagSize + kSmiShiftSize;
+    // Shift down and throw away top 32 bits.
+    return static_cast<int>(reinterpret_cast<intptr_t>(value) >> shift_bits);
+  }
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return internal::IntToSmi<kSmiShiftSize>(value);
+  }
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    // To be representable as a long smi, the value must be a 32-bit integer.
+    return (value == static_cast<int32_t>(value));
+  }
+};
+
+typedef SmiTagging<kApiPointerSize> PlatformSmiTagging;
+const int kSmiShiftSize = PlatformSmiTagging::kSmiShiftSize;
+const int kSmiValueSize = PlatformSmiTagging::kSmiValueSize;
+V8_INLINE static bool SmiValuesAre31Bits() { return kSmiValueSize == 31; }
+V8_INLINE static bool SmiValuesAre32Bits() { return kSmiValueSize == 32; }
+
+/**
+ * This class exports constants and functionality from within v8 that
+ * is necessary to implement inline functions in the v8 api.  Don't
+ * depend on functions and constants defined here.
+ */
+class Internals {
+ public:
+  // These values match non-compiler-dependent values defined within
+  // the implementation of v8.
+  static const int kHeapObjectMapOffset = 0;
+  static const int kMapInstanceTypeAndBitFieldOffset =
+      1 * kApiPointerSize + kApiIntSize;
+  static const int kStringResourceOffset = 3 * kApiPointerSize;
+
+  static const int kOddballKindOffset = 4 * kApiPointerSize + sizeof(double);
+  static const int kForeignAddressOffset = kApiPointerSize;
+  static const int kJSObjectHeaderSize = 3 * kApiPointerSize;
+  static const int kFixedArrayHeaderSize = 2 * kApiPointerSize;
+  static const int kContextHeaderSize = 2 * kApiPointerSize;
+  static const int kContextEmbedderDataIndex = 5;
+  static const int kFullStringRepresentationMask = 0x0f;
+  static const int kStringEncodingMask = 0x8;
+  static const int kExternalTwoByteRepresentationTag = 0x02;
+  static const int kExternalOneByteRepresentationTag = 0x0a;
+
+  static const int kIsolateEmbedderDataOffset = 0 * kApiPointerSize;
+  static const int kExternalMemoryOffset = 4 * kApiPointerSize;
+  static const int kExternalMemoryLimitOffset =
+      kExternalMemoryOffset + kApiInt64Size;
+  static const int kIsolateRootsOffset = kExternalMemoryLimitOffset +
+                                         kApiInt64Size + kApiInt64Size +
+                                         kApiPointerSize + kApiPointerSize;
+  static const int kUndefinedValueRootIndex = 4;
+  static const int kTheHoleValueRootIndex = 5;
+  static const int kNullValueRootIndex = 6;
+  static const int kTrueValueRootIndex = 7;
+  static const int kFalseValueRootIndex = 8;
+  static const int kEmptyStringRootIndex = 9;
+
+  static const int kNodeClassIdOffset = 1 * kApiPointerSize;
+  static const int kNodeFlagsOffset = 1 * kApiPointerSize + 3;
+  static const int kNodeStateMask = 0x7;
+  static const int kNodeStateIsWeakValue = 2;
+  static const int kNodeStateIsPendingValue = 3;
+  static const int kNodeStateIsNearDeathValue = 4;
+  static const int kNodeIsIndependentShift = 3;
+  static const int kNodeIsActiveShift = 4;
+
+  static const int kJSApiObjectType = 0xbb;
+  static const int kJSObjectType = 0xbc;
+  static const int kFirstNonstringType = 0x80;
+  static const int kOddballType = 0x82;
+  static const int kForeignType = 0x86;
+
+  static const int kUndefinedOddballKind = 5;
+  static const int kNullOddballKind = 3;
+
+  static const uint32_t kNumIsolateDataSlots = 4;
+
+  V8_EXPORT static void CheckInitializedImpl(v8::Isolate* isolate);
+  V8_INLINE static void CheckInitialized(v8::Isolate* isolate) {
+#ifdef V8_ENABLE_CHECKS
+    CheckInitializedImpl(isolate);
+#endif
+  }
+
+  V8_INLINE static bool HasHeapObjectTag(const internal::Object* value) {
+    return ((reinterpret_cast<intptr_t>(value) & kHeapObjectTagMask) ==
+            kHeapObjectTag);
+  }
+
+  V8_INLINE static int SmiValue(const internal::Object* value) {
+    return PlatformSmiTagging::SmiToInt(value);
+  }
+
+  V8_INLINE static internal::Object* IntToSmi(int value) {
+    return PlatformSmiTagging::IntToSmi(value);
+  }
+
+  V8_INLINE static bool IsValidSmi(intptr_t value) {
+    return PlatformSmiTagging::IsValidSmi(value);
+  }
+
+  V8_INLINE static int GetInstanceType(const internal::Object* obj) {
+    typedef internal::Object O;
+    O* map = ReadField<O*>(obj, kHeapObjectMapOffset);
+    // Map::InstanceType is defined so that it will always be loaded into
+    // the LS 8 bits of one 16-bit word, regardless of endianess.
+    return ReadField<uint16_t>(map, kMapInstanceTypeAndBitFieldOffset) & 0xff;
+  }
+
+  V8_INLINE static int GetOddballKind(const internal::Object* obj) {
+    typedef internal::Object O;
+    return SmiValue(ReadField<O*>(obj, kOddballKindOffset));
+  }
+
+  V8_INLINE static bool IsExternalTwoByteString(int instance_type) {
+    int representation = (instance_type & kFullStringRepresentationMask);
+    return representation == kExternalTwoByteRepresentationTag;
+  }
+
+  V8_INLINE static uint8_t GetNodeFlag(internal::Object** obj, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      return *addr & static_cast<uint8_t>(1U << shift);
+  }
+
+  V8_INLINE static void UpdateNodeFlag(internal::Object** obj,
+                                       bool value, int shift) {
+      uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+      uint8_t mask = static_cast<uint8_t>(1U << shift);
+      *addr = static_cast<uint8_t>((*addr & ~mask) | (value << shift));
+  }
+
+  V8_INLINE static uint8_t GetNodeState(internal::Object** obj) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    return *addr & kNodeStateMask;
+  }
+
+  V8_INLINE static void UpdateNodeState(internal::Object** obj,
+                                        uint8_t value) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + kNodeFlagsOffset;
+    *addr = static_cast<uint8_t>((*addr & ~kNodeStateMask) | value);
+  }
+
+  V8_INLINE static void SetEmbedderData(v8::Isolate* isolate,
+                                        uint32_t slot,
+                                        void* data) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) +
+                    kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    *reinterpret_cast<void**>(addr) = data;
+  }
+
+  V8_INLINE static void* GetEmbedderData(const v8::Isolate* isolate,
+                                         uint32_t slot) {
+    const uint8_t* addr = reinterpret_cast<const uint8_t*>(isolate) +
+        kIsolateEmbedderDataOffset + slot * kApiPointerSize;
+    return *reinterpret_cast<void* const*>(addr);
+  }
+
+  V8_INLINE static internal::Object** GetRoot(v8::Isolate* isolate,
+                                              int index) {
+    uint8_t* addr = reinterpret_cast<uint8_t*>(isolate) + kIsolateRootsOffset;
+    return reinterpret_cast<internal::Object**>(addr + index * kApiPointerSize);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadField(const internal::Object* ptr, int offset) {
+    const uint8_t* addr =
+        reinterpret_cast<const uint8_t*>(ptr) + offset - kHeapObjectTag;
+    return *reinterpret_cast<const T*>(addr);
+  }
+
+  template <typename T>
+  V8_INLINE static T ReadEmbedderData(const v8::Context* context, int index) {
+    typedef internal::Object O;
+    typedef internal::Internals I;
+    O* ctx = *reinterpret_cast<O* const*>(context);
+    int embedder_data_offset = I::kContextHeaderSize +
+        (internal::kApiPointerSize * I::kContextEmbedderDataIndex);
+    O* embedder_data = I::ReadField<O*>(ctx, embedder_data_offset);
+    int value_offset =
+        I::kFixedArrayHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<T>(embedder_data, value_offset);
+  }
+};
+
+}  // namespace internal
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, Local<T> that) {
+  return New(isolate, that.val_);
+}
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, const PersistentBase<T>& that) {
+  return New(isolate, that.val_);
+}
+
+
+template <class T>
+Local<T> Local<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return Local<T>();
+  T* that_ptr = that;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that_ptr);
+  return Local<T>(reinterpret_cast<T*>(HandleScope::CreateHandle(
+      reinterpret_cast<internal::Isolate*>(isolate), *p)));
+}
+
+
+template<class T>
+template<class S>
+void Eternal<T>::Set(Isolate* isolate, Local<S> handle) {
+  TYPE_CHECK(T, S);
+  val_ = reinterpret_cast<T*>(
+      V8::Eternalize(isolate, reinterpret_cast<Value*>(*handle)));
+}
+
+template <class T>
+Local<T> Eternal<T>::Get(Isolate* isolate) const {
+  // The eternal handle will never go away, so as with the roots, we don't even
+  // need to open a handle.
+  return Local<T>(val_);
+}
+
+
+template <class T>
+Local<T> MaybeLocal<T>::ToLocalChecked() {
+  if (V8_UNLIKELY(val_ == nullptr)) V8::ToLocalEmpty();
+  return Local<T>(val_);
+}
+
+
+template <class T>
+void* WeakCallbackInfo<T>::GetInternalField(int index) const {
+#ifdef V8_ENABLE_CHECKS
+  if (index < 0 || index >= kEmbedderFieldsInWeakCallback) {
+    V8::InternalFieldOutOfBounds(index);
+  }
+#endif
+  return embedder_fields_[index];
+}
+
+
+template <class T>
+T* PersistentBase<T>::New(Isolate* isolate, T* that) {
+  if (that == NULL) return NULL;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that);
+  return reinterpret_cast<T*>(
+      V8::GlobalizeReference(reinterpret_cast<internal::Isolate*>(isolate),
+                             p));
+}
+
+
+template <class T, class M>
+template <class S, class M2>
+void Persistent<T, M>::Copy(const Persistent<S, M2>& that) {
+  TYPE_CHECK(T, S);
+  this->Reset();
+  if (that.IsEmpty()) return;
+  internal::Object** p = reinterpret_cast<internal::Object**>(that.val_);
+  this->val_ = reinterpret_cast<T*>(V8::CopyPersistent(p));
+  M::Copy(that, this);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsIndependent() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                        I::kNodeIsIndependentShift);
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsNearDeath() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  uint8_t node_state =
+      I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_));
+  return node_state == I::kNodeStateIsNearDeathValue ||
+      node_state == I::kNodeStateIsPendingValue;
+}
+
+
+template <class T>
+bool PersistentBase<T>::IsWeak() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return false;
+  return I::GetNodeState(reinterpret_cast<internal::Object**>(this->val_)) ==
+      I::kNodeStateIsWeakValue;
+}
+
+
+template <class T>
+void PersistentBase<T>::Reset() {
+  if (this->IsEmpty()) return;
+  V8::DisposeGlobal(reinterpret_cast<internal::Object**>(this->val_));
+  val_ = 0;
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate, const Local<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <class S>
+void PersistentBase<T>::Reset(Isolate* isolate,
+                              const PersistentBase<S>& other) {
+  TYPE_CHECK(T, S);
+  Reset();
+  if (other.IsEmpty()) return;
+  this->val_ = New(isolate, other.val_);
+}
+
+
+template <class T>
+template <typename P>
+V8_INLINE void PersistentBase<T>::SetWeak(
+    P* parameter, typename WeakCallbackInfo<P>::Callback callback,
+    WeakCallbackType type) {
+  typedef typename WeakCallbackInfo<void>::Callback Callback;
+  V8::MakeWeak(reinterpret_cast<internal::Object**>(this->val_), parameter,
+               reinterpret_cast<Callback>(callback), type);
+}
+
+template <class T>
+void PersistentBase<T>::SetWeak() {
+  V8::MakeWeak(reinterpret_cast<internal::Object***>(&this->val_));
+}
+
+template <class T>
+template <typename P>
+P* PersistentBase<T>::ClearWeak() {
+  return reinterpret_cast<P*>(
+    V8::ClearWeak(reinterpret_cast<internal::Object**>(this->val_)));
+}
+
+template <class T>
+void PersistentBase<T>::RegisterExternalReference(Isolate* isolate) const {
+  if (IsEmpty()) return;
+  V8::RegisterExternallyReferencedObject(
+      reinterpret_cast<internal::Object**>(this->val_),
+      reinterpret_cast<internal::Isolate*>(isolate));
+}
+
+template <class T>
+void PersistentBase<T>::MarkIndependent() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_),
+                    true,
+                    I::kNodeIsIndependentShift);
+}
+
+template <class T>
+void PersistentBase<T>::MarkActive() {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  I::UpdateNodeFlag(reinterpret_cast<internal::Object**>(this->val_), true,
+                    I::kNodeIsActiveShift);
+}
+
+
+template <class T>
+void PersistentBase<T>::SetWrapperClassId(uint16_t class_id) {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  *reinterpret_cast<uint16_t*>(addr) = class_id;
+}
+
+
+template <class T>
+uint16_t PersistentBase<T>::WrapperClassId() const {
+  typedef internal::Internals I;
+  if (this->IsEmpty()) return 0;
+  internal::Object** obj = reinterpret_cast<internal::Object**>(this->val_);
+  uint8_t* addr = reinterpret_cast<uint8_t*>(obj) + I::kNodeClassIdOffset;
+  return *reinterpret_cast<uint16_t*>(addr);
+}
+
+
+template<typename T>
+ReturnValue<T>::ReturnValue(internal::Object** slot) : value_(slot) {}
+
+template<typename T>
+template<typename S>
+void ReturnValue<T>::Set(const Persistent<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Global<S>& handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(const Local<S> handle) {
+  TYPE_CHECK(T, S);
+  if (V8_UNLIKELY(handle.IsEmpty())) {
+    *value_ = GetDefaultValue();
+  } else {
+    *value_ = *reinterpret_cast<internal::Object**>(*handle);
+  }
+}
+
+template<typename T>
+void ReturnValue<T>::Set(double i) {
+  TYPE_CHECK(T, Number);
+  Set(Number::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(int32_t i) {
+  TYPE_CHECK(T, Integer);
+  typedef internal::Internals I;
+  if (V8_LIKELY(I::IsValidSmi(i))) {
+    *value_ = I::IntToSmi(i);
+    return;
+  }
+  Set(Integer::New(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(uint32_t i) {
+  TYPE_CHECK(T, Integer);
+  // Can't simply use INT32_MAX here for whatever reason.
+  bool fits_into_int32_t = (i & (1U << 31)) == 0;
+  if (V8_LIKELY(fits_into_int32_t)) {
+    Set(static_cast<int32_t>(i));
+    return;
+  }
+  Set(Integer::NewFromUnsigned(GetIsolate(), i));
+}
+
+template<typename T>
+void ReturnValue<T>::Set(bool value) {
+  TYPE_CHECK(T, Boolean);
+  typedef internal::Internals I;
+  int root_index;
+  if (value) {
+    root_index = I::kTrueValueRootIndex;
+  } else {
+    root_index = I::kFalseValueRootIndex;
+  }
+  *value_ = *I::GetRoot(GetIsolate(), root_index);
+}
+
+template<typename T>
+void ReturnValue<T>::SetNull() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kNullValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetUndefined() {
+  TYPE_CHECK(T, Primitive);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kUndefinedValueRootIndex);
+}
+
+template<typename T>
+void ReturnValue<T>::SetEmptyString() {
+  TYPE_CHECK(T, String);
+  typedef internal::Internals I;
+  *value_ = *I::GetRoot(GetIsolate(), I::kEmptyStringRootIndex);
+}
+
+template <typename T>
+Isolate* ReturnValue<T>::GetIsolate() const {
+  // Isolate is always the pointer below the default value on the stack.
+  return *reinterpret_cast<Isolate**>(&value_[-2]);
+}
+
+template <typename T>
+Local<Value> ReturnValue<T>::Get() const {
+  typedef internal::Internals I;
+  if (*value_ == *I::GetRoot(GetIsolate(), I::kTheHoleValueRootIndex))
+    return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>::New(GetIsolate(), reinterpret_cast<Value*>(value_));
+}
+
+template <typename T>
+template <typename S>
+void ReturnValue<T>::Set(S* whatever) {
+  // Uncompilable to prevent inadvertent misuse.
+  TYPE_CHECK(S*, Primitive);
+}
+
+template<typename T>
+internal::Object* ReturnValue<T>::GetDefaultValue() {
+  // Default value is always the pointer below value_ on the stack.
+  return value_[-1];
+}
+
+template <typename T>
+FunctionCallbackInfo<T>::FunctionCallbackInfo(internal::Object** implicit_args,
+                                              internal::Object** values,
+                                              int length)
+    : implicit_args_(implicit_args), values_(values), length_(length) {}
+
+template<typename T>
+Local<Value> FunctionCallbackInfo<T>::operator[](int i) const {
+  if (i < 0 || length_ <= i) return Local<Value>(*Undefined(GetIsolate()));
+  return Local<Value>(reinterpret_cast<Value*>(values_ - i));
+}
+
+
+template<typename T>
+Local<Function> FunctionCallbackInfo<T>::Callee() const {
+  return Local<Function>(reinterpret_cast<Function*>(
+      &implicit_args_[kCalleeIndex]));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
+}
+
+
+template<typename T>
+Local<Object> FunctionCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(
+      &implicit_args_[kHolderIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::NewTarget() const {
+  return Local<Value>(
+      reinterpret_cast<Value*>(&implicit_args_[kNewTargetIndex]));
+}
+
+template <typename T>
+Local<Value> FunctionCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&implicit_args_[kDataIndex]));
+}
+
+
+template<typename T>
+Isolate* FunctionCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&implicit_args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+ReturnValue<T> FunctionCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&implicit_args_[kReturnValueIndex]);
+}
+
+
+template<typename T>
+bool FunctionCallbackInfo<T>::IsConstructCall() const {
+  return !NewTarget()->IsUndefined();
+}
+
+
+template<typename T>
+int FunctionCallbackInfo<T>::Length() const {
+  return length_;
+}
+
+ScriptOrigin::ScriptOrigin(Local<Value> resource_name,
+                           Local<Integer> resource_line_offset,
+                           Local<Integer> resource_column_offset,
+                           Local<Boolean> resource_is_shared_cross_origin,
+                           Local<Integer> script_id,
+                           Local<Value> source_map_url,
+                           Local<Boolean> resource_is_opaque,
+                           Local<Boolean> is_wasm, Local<Boolean> is_module)
+    : resource_name_(resource_name),
+      resource_line_offset_(resource_line_offset),
+      resource_column_offset_(resource_column_offset),
+      options_(!resource_is_shared_cross_origin.IsEmpty() &&
+                   resource_is_shared_cross_origin->IsTrue(),
+               !resource_is_opaque.IsEmpty() && resource_is_opaque->IsTrue(),
+               !is_wasm.IsEmpty() && is_wasm->IsTrue(),
+               !is_module.IsEmpty() && is_module->IsTrue()),
+      script_id_(script_id),
+      source_map_url_(source_map_url) {}
+
+Local<Value> ScriptOrigin::ResourceName() const { return resource_name_; }
+
+
+Local<Integer> ScriptOrigin::ResourceLineOffset() const {
+  return resource_line_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ResourceColumnOffset() const {
+  return resource_column_offset_;
+}
+
+
+Local<Integer> ScriptOrigin::ScriptID() const { return script_id_; }
+
+
+Local<Value> ScriptOrigin::SourceMapUrl() const { return source_map_url_; }
+
+
+ScriptCompiler::Source::Source(Local<String> string, const ScriptOrigin& origin,
+                               CachedData* data)
+    : source_string(string),
+      resource_name(origin.ResourceName()),
+      resource_line_offset(origin.ResourceLineOffset()),
+      resource_column_offset(origin.ResourceColumnOffset()),
+      resource_options(origin.Options()),
+      source_map_url(origin.SourceMapUrl()),
+      cached_data(data) {}
+
+
+ScriptCompiler::Source::Source(Local<String> string,
+                               CachedData* data)
+    : source_string(string), cached_data(data) {}
+
+
+ScriptCompiler::Source::~Source() {
+  delete cached_data;
+}
+
+
+const ScriptCompiler::CachedData* ScriptCompiler::Source::GetCachedData()
+    const {
+  return cached_data;
+}
+
+const ScriptOriginOptions& ScriptCompiler::Source::GetResourceOptions() const {
+  return resource_options;
+}
+
+Local<Boolean> Boolean::New(Isolate* isolate, bool value) {
+  return value ? True(isolate) : False(isolate);
+}
+
+void Template::Set(Isolate* isolate, const char* name, Local<Data> value) {
+  Set(String::NewFromUtf8(isolate, name, NewStringType::kInternalized)
+          .ToLocalChecked(),
+      value);
+}
+
+
+Local<Value> Object::GetInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (instance_type == I::kJSObjectType ||
+      instance_type == I::kJSApiObjectType) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    O* value = I::ReadField<O*>(obj, offset);
+    O** result = HandleScope::CreateHandle(reinterpret_cast<HO*>(obj), value);
+    return Local<Value>(reinterpret_cast<Value*>(result));
+  }
+#endif
+  return SlowGetInternalField(index);
+}
+
+
+void* Object::GetAlignedPointerFromInternalField(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O**>(this);
+  // Fast path: If the object is a plain JSObject, which is the common case, we
+  // know where to find the internal fields and can return the value directly.
+  auto instance_type = I::GetInstanceType(obj);
+  if (V8_LIKELY(instance_type == I::kJSObjectType ||
+                instance_type == I::kJSApiObjectType)) {
+    int offset = I::kJSObjectHeaderSize + (internal::kApiPointerSize * index);
+    return I::ReadField<void*>(obj, offset);
+  }
+#endif
+  return SlowGetAlignedPointerFromInternalField(index);
+}
+
+String* String::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<String*>(value);
+}
+
+
+Local<String> String::Empty(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kEmptyStringRootIndex);
+  return Local<String>(reinterpret_cast<String*>(slot));
+}
+
+
+String::ExternalStringResource* String::GetExternalStringResource() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  String::ExternalStringResource* result;
+  if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    result = reinterpret_cast<String::ExternalStringResource*>(value);
+  } else {
+    result = NULL;
+  }
+#ifdef V8_ENABLE_CHECKS
+  VerifyExternalStringResource(result);
+#endif
+  return result;
+}
+
+
+String::ExternalStringResourceBase* String::GetExternalStringResourceBase(
+    String::Encoding* encoding_out) const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  int type = I::GetInstanceType(obj) & I::kFullStringRepresentationMask;
+  *encoding_out = static_cast<Encoding>(type & I::kStringEncodingMask);
+  ExternalStringResourceBase* resource = NULL;
+  if (type == I::kExternalOneByteRepresentationTag ||
+      type == I::kExternalTwoByteRepresentationTag) {
+    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    resource = static_cast<ExternalStringResourceBase*>(value);
+  }
+#ifdef V8_ENABLE_CHECKS
+    VerifyExternalStringResourceBase(resource, *encoding_out);
+#endif
+  return resource;
+}
+
+
+bool Value::IsUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsUndefined();
+#else
+  return QuickIsUndefined();
+#endif
+}
+
+bool Value::QuickIsUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kUndefinedOddballKind);
+}
+
+
+bool Value::IsNull() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull();
+#else
+  return QuickIsNull();
+#endif
+}
+
+bool Value::QuickIsNull() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  return (I::GetOddballKind(obj) == I::kNullOddballKind);
+}
+
+bool Value::IsNullOrUndefined() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsNull() || FullIsUndefined();
+#else
+  return QuickIsNullOrUndefined();
+#endif
+}
+
+bool Value::QuickIsNullOrUndefined() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  if (I::GetInstanceType(obj) != I::kOddballType) return false;
+  int kind = I::GetOddballKind(obj);
+  return kind == I::kNullOddballKind || kind == I::kUndefinedOddballKind;
+}
+
+bool Value::IsString() const {
+#ifdef V8_ENABLE_CHECKS
+  return FullIsString();
+#else
+  return QuickIsString();
+#endif
+}
+
+bool Value::QuickIsString() const {
+  typedef internal::Object O;
+  typedef internal::Internals I;
+  O* obj = *reinterpret_cast<O* const*>(this);
+  if (!I::HasHeapObjectTag(obj)) return false;
+  return (I::GetInstanceType(obj) < I::kFirstNonstringType);
+}
+
+
+template <class T> Value* Value::Cast(T* value) {
+  return static_cast<Value*>(value);
+}
+
+
+Local<Boolean> Value::ToBoolean() const {
+  return ToBoolean(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Boolean>());
+}
+
+
+Local<Number> Value::ToNumber() const {
+  return ToNumber(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Number>());
+}
+
+
+Local<String> Value::ToString() const {
+  return ToString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<String> Value::ToDetailString() const {
+  return ToDetailString(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<String>());
+}
+
+
+Local<Object> Value::ToObject() const {
+  return ToObject(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Object>());
+}
+
+
+Local<Integer> Value::ToInteger() const {
+  return ToInteger(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Integer>());
+}
+
+
+Local<Uint32> Value::ToUint32() const {
+  return ToUint32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Uint32>());
+}
+
+
+Local<Int32> Value::ToInt32() const {
+  return ToInt32(Isolate::GetCurrent()->GetCurrentContext())
+      .FromMaybe(Local<Int32>());
+}
+
+
+Boolean* Boolean::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Boolean*>(value);
+}
+
+
+Name* Name::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Name*>(value);
+}
+
+
+Symbol* Symbol::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Symbol*>(value);
+}
+
+
+Number* Number::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Number*>(value);
+}
+
+
+Integer* Integer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Integer*>(value);
+}
+
+
+Int32* Int32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32*>(value);
+}
+
+
+Uint32* Uint32::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32*>(value);
+}
+
+
+Date* Date::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Date*>(value);
+}
+
+
+StringObject* StringObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<StringObject*>(value);
+}
+
+
+SymbolObject* SymbolObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SymbolObject*>(value);
+}
+
+
+NumberObject* NumberObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<NumberObject*>(value);
+}
+
+
+BooleanObject* BooleanObject::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<BooleanObject*>(value);
+}
+
+
+RegExp* RegExp::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<RegExp*>(value);
+}
+
+
+Object* Object::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Object*>(value);
+}
+
+
+Array* Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Array*>(value);
+}
+
+
+Map* Map::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Map*>(value);
+}
+
+
+Set* Set::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Set*>(value);
+}
+
+
+Promise* Promise::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise*>(value);
+}
+
+
+Proxy* Proxy::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Proxy*>(value);
+}
+
+WasmCompiledModule* WasmCompiledModule::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<WasmCompiledModule*>(value);
+}
+
+Promise::Resolver* Promise::Resolver::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Promise::Resolver*>(value);
+}
+
+
+ArrayBuffer* ArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBuffer*>(value);
+}
+
+
+ArrayBufferView* ArrayBufferView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<ArrayBufferView*>(value);
+}
+
+
+TypedArray* TypedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<TypedArray*>(value);
+}
+
+
+Uint8Array* Uint8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8Array*>(value);
+}
+
+
+Int8Array* Int8Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int8Array*>(value);
+}
+
+
+Uint16Array* Uint16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint16Array*>(value);
+}
+
+
+Int16Array* Int16Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int16Array*>(value);
+}
+
+
+Uint32Array* Uint32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint32Array*>(value);
+}
+
+
+Int32Array* Int32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Int32Array*>(value);
+}
+
+
+Float32Array* Float32Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float32Array*>(value);
+}
+
+
+Float64Array* Float64Array::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Float64Array*>(value);
+}
+
+
+Uint8ClampedArray* Uint8ClampedArray::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Uint8ClampedArray*>(value);
+}
+
+
+DataView* DataView::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<DataView*>(value);
+}
+
+
+SharedArrayBuffer* SharedArrayBuffer::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<SharedArrayBuffer*>(value);
+}
+
+
+Function* Function::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<Function*>(value);
+}
+
+
+External* External::Cast(v8::Value* value) {
+#ifdef V8_ENABLE_CHECKS
+  CheckCast(value);
+#endif
+  return static_cast<External*>(value);
+}
+
+
+template<typename T>
+Isolate* PropertyCallbackInfo<T>::GetIsolate() const {
+  return *reinterpret_cast<Isolate**>(&args_[kIsolateIndex]);
+}
+
+
+template<typename T>
+Local<Value> PropertyCallbackInfo<T>::Data() const {
+  return Local<Value>(reinterpret_cast<Value*>(&args_[kDataIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::This() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kThisIndex]));
+}
+
+
+template<typename T>
+Local<Object> PropertyCallbackInfo<T>::Holder() const {
+  return Local<Object>(reinterpret_cast<Object*>(&args_[kHolderIndex]));
+}
+
+
+template<typename T>
+ReturnValue<T> PropertyCallbackInfo<T>::GetReturnValue() const {
+  return ReturnValue<T>(&args_[kReturnValueIndex]);
+}
+
+template <typename T>
+bool PropertyCallbackInfo<T>::ShouldThrowOnError() const {
+  typedef internal::Internals I;
+  return args_[kShouldThrowOnErrorIndex] != I::IntToSmi(0);
+}
+
+
+Local<Primitive> Undefined(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kUndefinedValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Primitive> Null(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kNullValueRootIndex);
+  return Local<Primitive>(reinterpret_cast<Primitive*>(slot));
+}
+
+
+Local<Boolean> True(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kTrueValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+Local<Boolean> False(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  I::CheckInitialized(isolate);
+  S* slot = I::GetRoot(isolate, I::kFalseValueRootIndex);
+  return Local<Boolean>(reinterpret_cast<Boolean*>(slot));
+}
+
+
+void Isolate::SetData(uint32_t slot, void* data) {
+  typedef internal::Internals I;
+  I::SetEmbedderData(this, slot, data);
+}
+
+
+void* Isolate::GetData(uint32_t slot) {
+  typedef internal::Internals I;
+  return I::GetEmbedderData(this, slot);
+}
+
+
+uint32_t Isolate::GetNumberOfDataSlots() {
+  typedef internal::Internals I;
+  return I::kNumIsolateDataSlots;
+}
+
+
+int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
+    int64_t change_in_bytes) {
+  typedef internal::Internals I;
+  int64_t* external_memory = reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryOffset);
+  const int64_t external_memory_limit = *reinterpret_cast<int64_t*>(
+      reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryLimitOffset);
+  const int64_t amount = *external_memory + change_in_bytes;
+  *external_memory = amount;
+  if (change_in_bytes > 0 && amount > external_memory_limit) {
+    ReportExternalAllocationLimitReached();
+  }
+  return *external_memory;
+}
+
+Local<Value> Context::GetEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Object O;
+  typedef internal::HeapObject HO;
+  typedef internal::Internals I;
+  HO* context = *reinterpret_cast<HO**>(this);
+  O** result =
+      HandleScope::CreateHandle(context, I::ReadEmbedderData<O*>(this, index));
+  return Local<Value>(reinterpret_cast<Value*>(result));
+#else
+  return SlowGetEmbedderData(index);
+#endif
+}
+
+
+void* Context::GetAlignedPointerFromEmbedderData(int index) {
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Internals I;
+  return I::ReadEmbedderData<void*>(this, index);
+#else
+  return SlowGetAlignedPointerFromEmbedderData(index);
+#endif
+}
+
+
+void V8::SetAllowCodeGenerationFromStringsCallback(
+    AllowCodeGenerationFromStringsCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetAllowCodeGenerationFromStringsCallback(callback);
+}
+
+
+bool V8::IsDead() {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->IsDead();
+}
+
+
+bool V8::AddMessageListener(MessageCallback that, Local<Value> data) {
+  Isolate* isolate = Isolate::GetCurrent();
+  return isolate->AddMessageListener(that, data);
+}
+
+
+void V8::RemoveMessageListeners(MessageCallback that) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveMessageListeners(that);
+}
+
+
+void V8::SetFailedAccessCheckCallbackFunction(
+    FailedAccessCheckCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFailedAccessCheckCallbackFunction(callback);
+}
+
+
+void V8::SetCaptureStackTraceForUncaughtExceptions(
+    bool capture, int frame_limit, StackTrace::StackTraceOptions options) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetCaptureStackTraceForUncaughtExceptions(capture, frame_limit,
+                                                     options);
+}
+
+
+void V8::SetFatalErrorHandler(FatalErrorCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->SetFatalErrorHandler(callback);
+}
+
+void V8::RemoveGCPrologueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCPrologueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+
+void V8::RemoveGCEpilogueCallback(GCCallback callback) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->RemoveGCEpilogueCallback(
+      reinterpret_cast<Isolate::GCCallback>(callback));
+}
+
+void V8::TerminateExecution(Isolate* isolate) { isolate->TerminateExecution(); }
+
+
+bool V8::IsExecutionTerminating(Isolate* isolate) {
+  if (isolate == NULL) {
+    isolate = Isolate::GetCurrent();
+  }
+  return isolate->IsExecutionTerminating();
+}
+
+
+void V8::CancelTerminateExecution(Isolate* isolate) {
+  isolate->CancelTerminateExecution();
+}
+
+
+void V8::VisitExternalResources(ExternalResourceVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitExternalResources(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(PersistentHandleVisitor* visitor) {
+  Isolate* isolate = Isolate::GetCurrent();
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesWithClassIds(Isolate* isolate,
+                                  PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesWithClassIds(visitor);
+}
+
+
+void V8::VisitHandlesForPartialDependence(Isolate* isolate,
+                                          PersistentHandleVisitor* visitor) {
+  isolate->VisitHandlesForPartialDependence(visitor);
+}
+
+/**
+ * \example shell.cc
+ * A simple shell that takes a list of expressions on the
+ * command-line and executes them.
+ */
+
+
+/**
+ * \example process.cc
+ */
+
+
+}  // namespace v8
+
+
+#undef TYPE_CHECK
+
+
+#endif  // INCLUDE_V8_H_
diff --git a/android/x86/include/v8/v8config.h b/android/x86/include/v8/v8config.h
new file mode 100644
index 00000000..964949c2
--- /dev/null
+++ b/android/x86/include/v8/v8config.h
@@ -0,0 +1,428 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8CONFIG_H_
+#define V8CONFIG_H_
+
+// clang-format off
+
+// Platform headers for feature detection below.
+#if defined(__ANDROID__)
+# include <sys/cdefs.h>
+#elif defined(__APPLE__)
+# include <TargetConditionals.h>
+#elif defined(__linux__)
+# include <features.h>
+#endif
+
+
+// This macro allows to test for the version of the GNU C library (or
+// a compatible C library that masquerades as glibc). It evaluates to
+// 0 if libc is not GNU libc or compatible.
+// Use like:
+//  #if V8_GLIBC_PREREQ(2, 3)
+//   ...
+//  #endif
+#if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
+# define V8_GLIBC_PREREQ(major, minor)                                    \
+    ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
+#else
+# define V8_GLIBC_PREREQ(major, minor) 0
+#endif
+
+
+// This macro allows to test for the version of the GNU C++ compiler.
+// Note that this also applies to compilers that masquerade as GCC,
+// for example clang and the Intel C++ compiler for Linux.
+// Use like:
+//  #if V8_GNUC_PREREQ(4, 3, 1)
+//   ...
+//  #endif
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)                         \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >=   \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
+# define V8_GNUC_PREREQ(major, minor, patchlevel)      \
+    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >=      \
+     ((major) * 10000 + (minor) * 100 + (patchlevel)))
+#else
+# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
+#endif
+
+
+
+// -----------------------------------------------------------------------------
+// Operating system detection
+//
+//  V8_OS_ANDROID       - Android
+//  V8_OS_BSD           - BSDish (Mac OS X, Net/Free/Open/DragonFlyBSD)
+//  V8_OS_CYGWIN        - Cygwin
+//  V8_OS_DRAGONFLYBSD  - DragonFlyBSD
+//  V8_OS_FREEBSD       - FreeBSD
+//  V8_OS_LINUX         - Linux
+//  V8_OS_MACOSX        - Mac OS X
+//  V8_OS_NETBSD        - NetBSD
+//  V8_OS_OPENBSD       - OpenBSD
+//  V8_OS_POSIX         - POSIX compatible (mostly everything except Windows)
+//  V8_OS_QNX           - QNX Neutrino
+//  V8_OS_SOLARIS       - Sun Solaris and OpenSolaris
+//  V8_OS_AIX           - AIX
+//  V8_OS_WIN           - Microsoft Windows
+
+#if defined(__ANDROID__)
+# define V8_OS_ANDROID 1
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__APPLE__)
+# define V8_OS_BSD 1
+# define V8_OS_MACOSX 1
+# define V8_OS_POSIX 1
+#elif defined(__CYGWIN__)
+# define V8_OS_CYGWIN 1
+# define V8_OS_POSIX 1
+#elif defined(__linux__)
+# define V8_OS_LINUX 1
+# define V8_OS_POSIX 1
+#elif defined(__sun)
+# define V8_OS_POSIX 1
+# define V8_OS_SOLARIS 1
+#elif defined(_AIX)
+#define V8_OS_POSIX 1
+#define V8_OS_AIX 1
+#elif defined(__FreeBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_FREEBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__DragonFly__)
+# define V8_OS_BSD 1
+# define V8_OS_DRAGONFLYBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__NetBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_NETBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__OpenBSD__)
+# define V8_OS_BSD 1
+# define V8_OS_OPENBSD 1
+# define V8_OS_POSIX 1
+#elif defined(__QNXNTO__)
+# define V8_OS_POSIX 1
+# define V8_OS_QNX 1
+#elif defined(_WIN32)
+# define V8_OS_WIN 1
+#endif
+
+
+// -----------------------------------------------------------------------------
+// C library detection
+//
+//  V8_LIBC_MSVCRT  - MSVC libc
+//  V8_LIBC_BIONIC  - Bionic libc
+//  V8_LIBC_BSD     - BSD libc derivate
+//  V8_LIBC_GLIBC   - GNU C library
+//  V8_LIBC_UCLIBC  - uClibc
+//
+// Note that testing for libc must be done using #if not #ifdef. For example,
+// to test for the GNU C library, use:
+//  #if V8_LIBC_GLIBC
+//   ...
+//  #endif
+
+#if defined (_MSC_VER)
+# define V8_LIBC_MSVCRT 1
+#elif defined(__BIONIC__)
+# define V8_LIBC_BIONIC 1
+# define V8_LIBC_BSD 1
+#elif defined(__UCLIBC__)
+// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
+# define V8_LIBC_UCLIBC 1
+#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
+# define V8_LIBC_GLIBC 1
+#else
+# define V8_LIBC_BSD V8_OS_BSD
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Compiler detection
+//
+//  V8_CC_GNU     - GCC, or clang in gcc mode
+//  V8_CC_INTEL   - Intel C++
+//  V8_CC_MINGW   - Minimalist GNU for Windows
+//  V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
+//  V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
+//  V8_CC_MSVC    - Microsoft Visual C/C++, or clang in cl.exe mode
+//
+// C++11 feature detection
+//
+//  V8_HAS_CXX11_ALIGNAS        - alignas specifier supported
+//  V8_HAS_CXX11_ALIGNOF        - alignof(type) operator supported
+//
+// Compiler-specific feature detection
+//
+//  V8_HAS___ALIGNOF                    - __alignof(type) operator supported
+//  V8_HAS___ALIGNOF__                  - __alignof__(type) operator supported
+//  V8_HAS_ATTRIBUTE_ALIGNED            - __attribute__((aligned(n))) supported
+//  V8_HAS_ATTRIBUTE_ALWAYS_INLINE      - __attribute__((always_inline))
+//                                        supported
+//  V8_HAS_ATTRIBUTE_DEPRECATED         - __attribute__((deprecated)) supported
+//  V8_HAS_ATTRIBUTE_NOINLINE           - __attribute__((noinline)) supported
+//  V8_HAS_ATTRIBUTE_NORETURN           - __attribute__((noreturn)) supported
+//  V8_HAS_ATTRIBUTE_UNUSED             - __attribute__((unused)) supported
+//  V8_HAS_ATTRIBUTE_VISIBILITY         - __attribute__((visibility)) supported
+//  V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
+//                                        supported
+//  V8_HAS_BUILTIN_CLZ                  - __builtin_clz() supported
+//  V8_HAS_BUILTIN_CTZ                  - __builtin_ctz() supported
+//  V8_HAS_BUILTIN_EXPECT               - __builtin_expect() supported
+//  V8_HAS_BUILTIN_FRAME_ADDRESS        - __builtin_frame_address() supported
+//  V8_HAS_BUILTIN_POPCOUNT             - __builtin_popcount() supported
+//  V8_HAS_BUILTIN_SADD_OVERFLOW        - __builtin_sadd_overflow() supported
+//  V8_HAS_BUILTIN_SSUB_OVERFLOW        - __builtin_ssub_overflow() supported
+//  V8_HAS_BUILTIN_UADD_OVERFLOW        - __builtin_uadd_overflow() supported
+//  V8_HAS_DECLSPEC_ALIGN               - __declspec(align(n)) supported
+//  V8_HAS_DECLSPEC_DEPRECATED          - __declspec(deprecated) supported
+//  V8_HAS_DECLSPEC_NOINLINE            - __declspec(noinline) supported
+//  V8_HAS_DECLSPEC_SELECTANY           - __declspec(selectany) supported
+//  V8_HAS_DECLSPEC_NORETURN            - __declspec(noreturn) supported
+//  V8_HAS___FORCEINLINE                - __forceinline supported
+//
+// Note that testing for compilers and/or features must be done using #if
+// not #ifdef. For example, to test for Intel C++ Compiler, use:
+//  #if V8_CC_INTEL
+//   ...
+//  #endif
+
+#if defined(__clang__)
+
+#if defined(__GNUC__)  // Clang in gcc mode.
+# define V8_CC_GNU 1
+#endif
+
+// Clang defines __alignof__ as alias for __alignof
+# define V8_HAS___ALIGNOF 1
+# define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
+# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
+# define V8_HAS_ATTRIBUTE_NORETURN (__has_attribute(noreturn))
+# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (__has_attribute(warn_unused_result))
+
+# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
+# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
+# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
+# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
+# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
+# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
+# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
+
+# define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
+
+#elif defined(__GNUC__)
+
+# define V8_CC_GNU 1
+# if defined(__INTEL_COMPILER)  // Intel C++ also masquerades as GCC 3.2.0
+#  define V8_CC_INTEL 1
+# endif
+# if defined(__MINGW32__)
+#  define V8_CC_MINGW32 1
+# endif
+# if defined(__MINGW64__)
+#  define V8_CC_MINGW64 1
+# endif
+# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
+
+# define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
+
+# define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
+// always_inline is available in gcc 4.0 but not very reliable until 4.4.
+// Works around "sorry, unimplemented: inlining failed" build errors with
+// older compilers.
+# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (V8_GNUC_PREREQ(4, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
+# define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_ATTRIBUTE_NORETURN (V8_GNUC_PREREQ(2, 5, 0))
+# define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
+# define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
+# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
+    (!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
+
+# define V8_HAS_BUILTIN_CLZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_CTZ (V8_GNUC_PREREQ(3, 4, 0))
+# define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_FRAME_ADDRESS (V8_GNUC_PREREQ(2, 96, 0))
+# define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
+
+# if __cplusplus >= 201103L
+#  define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
+#  define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
+# endif
+#endif
+
+#if defined(_MSC_VER)
+# define V8_CC_MSVC 1
+# define V8_HAS___ALIGNOF 1
+
+# define V8_HAS_DECLSPEC_ALIGN 1
+# define V8_HAS_DECLSPEC_DEPRECATED 1
+# define V8_HAS_DECLSPEC_NOINLINE 1
+# define V8_HAS_DECLSPEC_SELECTANY 1
+# define V8_HAS_DECLSPEC_NORETURN 1
+
+# define V8_HAS___FORCEINLINE 1
+
+#endif
+
+
+// -----------------------------------------------------------------------------
+// Helper macros
+
+// A macro used to make better inlining. Don't bother for debug builds.
+// Use like:
+//   V8_INLINE int GetZero() { return 0; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
+# define V8_INLINE inline __attribute__((always_inline))
+#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
+# define V8_INLINE __forceinline
+#else
+# define V8_INLINE inline
+#endif
+
+
+// A macro used to tell the compiler to never inline a particular function.
+// Don't bother for debug builds.
+// Use like:
+//   V8_NOINLINE int GetMinusOne() { return -1; }
+#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
+# define V8_NOINLINE __attribute__((noinline))
+#elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
+# define V8_NOINLINE __declspec(noinline)
+#else
+# define V8_NOINLINE /* NOT SUPPORTED */
+#endif
+
+
+// A macro used to tell the compiler that a particular function never returns.
+// Use like:
+//   V8_NORETURN void MyAbort() { abort(); }
+#if V8_HAS_ATTRIBUTE_NORETURN
+# define V8_NORETURN __attribute__((noreturn))
+#elif V8_HAS_DECLSPEC_NORETURN
+# define V8_NORETURN __declspec(noreturn)
+#else
+# define V8_NORETURN /* NOT SUPPORTED */
+#endif
+
+
+// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
+#if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATED(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATED(message, declarator) declarator
+#endif
+
+
+// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
+#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) && \
+    V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated(message)))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) \
+  declarator __attribute__((deprecated))
+#elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
+#define V8_DEPRECATE_SOON(message, declarator) __declspec(deprecated) declarator
+#else
+#define V8_DEPRECATE_SOON(message, declarator) declarator
+#endif
+
+
+// A macro to provide the compiler with branch prediction information.
+#if V8_HAS_BUILTIN_EXPECT
+# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
+# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
+#else
+# define V8_UNLIKELY(condition) (condition)
+# define V8_LIKELY(condition) (condition)
+#endif
+
+
+// This macro allows to specify memory alignment for structs, classes, etc.
+// Use like:
+//   class V8_ALIGNED(16) MyClass { ... };
+//   V8_ALIGNED(32) int array[42];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNED(n) alignas(n)
+#elif V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNED(n) __attribute__((aligned(n)))
+#elif V8_HAS_DECLSPEC_ALIGN
+# define V8_ALIGNED(n) __declspec(align(n))
+#else
+# define V8_ALIGNED(n) /* NOT SUPPORTED */
+#endif
+
+
+// This macro is similar to V8_ALIGNED(), but takes a type instead of size
+// in bytes. If the compiler does not supports using the alignment of the
+// |type|, it will align according to the |alignment| instead. For example,
+// Visual Studio C++ cannot combine __declspec(align) and __alignof. The
+// |alignment| must be a literal that is used as a kind of worst-case fallback
+// alignment.
+// Use like:
+//   struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
+//   V8_ALIGNAS(double, 8) int array[100];
+#if V8_HAS_CXX11_ALIGNAS
+# define V8_ALIGNAS(type, alignment) alignas(type)
+#elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
+# define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
+#else
+# define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
+#endif
+
+
+// This macro returns alignment in bytes (an integer power of two) required for
+// any instance of the given type, which is either complete type, an array type,
+// or a reference type.
+// Use like:
+//   size_t alignment = V8_ALIGNOF(double);
+#if V8_HAS_CXX11_ALIGNOF
+# define V8_ALIGNOF(type) alignof(type)
+#elif V8_HAS___ALIGNOF
+# define V8_ALIGNOF(type) __alignof(type)
+#elif V8_HAS___ALIGNOF__
+# define V8_ALIGNOF(type) __alignof__(type)
+#else
+// Note that alignment of a type within a struct can be less than the
+// alignment of the type stand-alone (because of ancient ABIs), so this
+// should only be used as a last resort.
+namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
+# define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
+#endif
+
+// Annotate a function indicating the caller must examine the return value.
+// Use like:
+//   int foo() WARN_UNUSED_RESULT;
+#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
+#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
+#endif
+
+// clang-format on
+
+#endif  // V8CONFIG_H_
diff --git a/android/x86/libinspector.a b/android/x86/libinspector.a
new file mode 100644
index 00000000..08adc373
Binary files /dev/null and b/android/x86/libinspector.a differ
diff --git a/android/x86/libv8_base.a b/android/x86/libv8_base.a
new file mode 100644
index 00000000..12717cc4
Binary files /dev/null and b/android/x86/libv8_base.a differ
diff --git a/android/x86/libv8_builtins_generators.a b/android/x86/libv8_builtins_generators.a
new file mode 100644
index 00000000..fc2ea889
Binary files /dev/null and b/android/x86/libv8_builtins_generators.a differ
diff --git a/android/x86/libv8_builtins_setup.a b/android/x86/libv8_builtins_setup.a
new file mode 100644
index 00000000..beb62907
Binary files /dev/null and b/android/x86/libv8_builtins_setup.a differ
diff --git a/android/x86/libv8_libbase.a b/android/x86/libv8_libbase.a
new file mode 100644
index 00000000..b8d68f79
Binary files /dev/null and b/android/x86/libv8_libbase.a differ
diff --git a/android/x86/libv8_libplatform.a b/android/x86/libv8_libplatform.a
new file mode 100644
index 00000000..e72b8be6
Binary files /dev/null and b/android/x86/libv8_libplatform.a differ
diff --git a/android/x86/libv8_libsampler.a b/android/x86/libv8_libsampler.a
new file mode 100644
index 00000000..2b9a676b
Binary files /dev/null and b/android/x86/libv8_libsampler.a differ
diff --git a/android/x86/libv8_nosnapshot.a b/android/x86/libv8_nosnapshot.a
new file mode 100644
index 00000000..05a4d26b
Binary files /dev/null and b/android/x86/libv8_nosnapshot.a differ