Merge V8 5.8.283.32

Test: Build V8 for arm, arm64, x86, x86_64, mips, mips64 and
set a PAC script from the UI on bullhead

Change-Id: I7cc773b5daca34d869e768a1deebae3876f2dfac

8 files changed, 497 insertions, 254 deletions

diff --git a/include/libplatform/libplatform.h b/include/libplatform/libplatform.h
index 40f3f668..cab467fd 100644
--- a/include/libplatform/libplatform.h
+++ b/include/libplatform/libplatform.h
@@ -35,6 +35,17 @@ V8_PLATFORM_EXPORT bool PumpMessageLoop(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|.
diff --git a/include/v8-debug.h b/include/v8-debug.h
index 6385a31d..797d2331 100644
--- a/include/v8-debug.h
+++ b/include/v8-debug.h
@@ -16,11 +16,9 @@ namespace v8 {
 enum DebugEvent {
   Break = 1,
   Exception = 2,
-  NewFunction = 3,
-  BeforeCompile = 4,
-  AfterCompile = 5,
-  CompileError = 6,
-  AsyncTaskEvent = 7,
+  AfterCompile = 3,
+  CompileError = 4,
+  AsyncTaskEvent = 5,
 };
 
 class V8_EXPORT Debug {
@@ -87,7 +85,6 @@ class V8_EXPORT Debug {
     virtual ~Message() {}
   };
 
-
   /**
    * An event details object passed to the debug event listener.
    */
@@ -119,9 +116,7 @@ class V8_EXPORT Debug {
     virtual Local<Value> GetCallbackData() const = 0;
 
     /**
-     * Client data passed to DebugBreakForCommand function. The
-     * debugger takes ownership of the data and will delete it even if
-     * there is no message handler.
+     * This is now a dummy that returns nullptr.
      */
     virtual ClientData* GetClientData() const = 0;
 
@@ -135,23 +130,18 @@ class V8_EXPORT Debug {
    *
    * \param event_details object providing information about the debug event
    *
-   * A EventCallback2 does not take possession of the event data,
+   * 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);
 
   /**
-   * Debug message callback function.
-   *
-   * \param message the debug message handler message object
-   *
-   * A MessageHandler2 does not take possession of the message data,
-   * and must not rely on the data persisting after the handler returns.
+   * This is now a no-op.
    */
   typedef void (*MessageHandler)(const Message& message);
 
   /**
-   * Callback function for the host to ensure debug messages are processed.
+   * This is now a no-op.
    */
   typedef void (*DebugMessageDispatchHandler)();
 
@@ -167,76 +157,46 @@ class V8_EXPORT Debug {
   static void CancelDebugBreak(Isolate* isolate);
 
   // Check if a debugger break is scheduled in the given isolate.
-  static bool CheckDebugBreak(Isolate* isolate);
-
-  // Message based interface. The message protocol is JSON.
-  static void SetMessageHandler(Isolate* isolate, MessageHandler handler);
-
-  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
-  */
-  // TODO(dcarney): data arg should be a MaybeLocal
-  static MaybeLocal<Value> Call(Local<Context> context,
-                                v8::Local<v8::Function> fun,
-                                Local<Value> data = Local<Value>());
+  V8_DEPRECATED("No longer supported",
+                static bool CheckDebugBreak(Isolate* isolate));
 
-  /**
-   * Returns a mirror object for the given object.
-   */
-  static MaybeLocal<Value> GetMirror(Local<Context> context,
-                                     v8::Local<v8::Value> obj);
+  // 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));
 
   /**
-   * Makes V8 process all pending debug messages.
-   *
-   * From V8 point of view all debug messages come asynchronously (e.g. from
-   * remote debugger) but they all must be handled synchronously: V8 cannot
-   * do 2 things at one time so normal script execution must be interrupted
-   * for a while.
-   *
-   * Generally when message arrives V8 may be in one of 3 states:
-   * 1. V8 is running script; V8 will automatically interrupt and process all
-   * pending messages;
-   * 2. V8 is suspended on debug breakpoint; in this state V8 is dedicated
-   * to reading and processing debug messages;
-   * 3. V8 is not running at all or has called some long-working C++ function;
-   * by default it means that processing of all debug messages will be deferred
-   * until V8 gets control again; however, embedding application may improve
-   * this by manually calling this method.
+   * 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.
    *
-   * Technically this method in many senses is equivalent to executing empty
-   * script:
-   * 1. It does nothing except for processing all pending debug messages.
-   * 2. It should be invoked with the same precautions and from the same context
-   * as V8 script would be invoked from, because:
-   *   a. with "evaluate" command it can do whatever normal script can do,
-   *   including all native calls;
-   *   b. no other thread should call V8 while this method is running
-   *   (v8::Locker may be used here).
-   *
-   * "Evaluate" debug command behavior currently is not specified in scope
-   * of this method.
+   * \code
+   *   function frame_source_line(exec_state) {
+   *     return exec_state.frame(0).sourceLine();
+   *   }
+   * \endcode
    */
-  static void ProcessDebugMessages(Isolate* isolate);
+  // TODO(dcarney): data arg should be a MaybeLocal
+  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
@@ -245,13 +205,16 @@ class V8_EXPORT Debug {
    * to change. The Context exists only when the debugger is active, i.e. at
    * least one DebugEventListener or MessageHandler is set.
    */
-  static Local<Context> GetDebugContext(Isolate* isolate);
+  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.
    */
-  static MaybeLocal<Context> GetDebuggedContext(Isolate* isolate);
+  V8_DEPRECATED(
+      "No longer supported",
+      static MaybeLocal<Context> GetDebuggedContext(Isolate* isolate));
 
   /**
    * Enable/disable LiveEdit functionality for the given Isolate
diff --git a/include/v8-inspector.h b/include/v8-inspector.h
index 0855ac10..c7209ed6 100644
--- a/include/v8-inspector.h
+++ b/include/v8-inspector.h
@@ -85,6 +85,8 @@ class V8_EXPORT V8ContextInfo {
   StringView auxData;
   bool hasMemoryOnConsole;
 
+  static int executionContextId(v8::Local<v8::Context> context);
+
  private:
   // Disallow copying and allocating this one.
   enum NotNullTagEnum { NotNullLiteral };
@@ -156,8 +158,6 @@ class V8_EXPORT V8InspectorSession {
   virtual void releaseObjectGroup(const StringView&) = 0;
 };
 
-enum class V8ConsoleAPIType { kClear, kDebug, kLog, kInfo, kWarning, kError };
-
 class V8_EXPORT V8InspectorClient {
  public:
   virtual ~V8InspectorClient() {}
@@ -189,7 +189,8 @@ class V8_EXPORT V8InspectorClient {
 
   virtual void installAdditionalCommandLineAPI(v8::Local<v8::Context>,
                                                v8::Local<v8::Object>) {}
-  virtual void consoleAPIMessage(int contextGroupId, V8ConsoleAPIType,
+  virtual void consoleAPIMessage(int contextGroupId,
+                                 v8::Isolate::MessageErrorLevel level,
                                  const StringView& message,
                                  const StringView& url, unsigned lineNumber,
                                  unsigned columnNumber, V8StackTrace*) {}
@@ -201,6 +202,7 @@ class V8_EXPORT V8InspectorClient {
   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) {}
@@ -248,9 +250,9 @@ class V8_EXPORT V8Inspector {
   class V8_EXPORT Channel {
    public:
     virtual ~Channel() {}
-    virtual void sendProtocolResponse(int callId,
-                                      const StringView& message) = 0;
-    virtual void sendProtocolNotification(const StringView& message) = 0;
+    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(
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index 74c06139..f7d182f8 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -5,6 +5,7 @@
 #ifndef V8_V8_PROFILER_H_
 #define V8_V8_PROFILER_H_
 
+#include <unordered_set>
 #include <vector>
 #include "v8.h"  // NOLINT(build/include)
 
@@ -392,8 +393,7 @@ class V8_EXPORT HeapGraphNode {
                          // 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).
-    kSimdValue = 13      // A SIMD value stored in the heap (Proposed ES7).
+    kSymbol = 12         // A Symbol (ES6).
   };
 
   /** Returns node type (see HeapGraphNode::Type). */
@@ -630,6 +630,24 @@ class V8_EXPORT HeapProfiler {
     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
@@ -782,6 +800,8 @@ class V8_EXPORT HeapProfiler {
       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
diff --git a/include/v8-util.h b/include/v8-util.h
index 8133fdd4..a04a5e84 100644
--- a/include/v8-util.h
+++ b/include/v8-util.h
@@ -6,6 +6,7 @@
 #define V8_UTIL_H_
 
 #include "v8.h"  // NOLINT(build/include)
+#include <assert.h>
 #include <map>
 #include <vector>
 
@@ -210,7 +211,7 @@ class PersistentValueMapBase {
    * key.
    */
   void RegisterExternallyReferencedObject(K& key) {
-    DCHECK(Contains(key));
+    assert(Contains(key));
     V8::RegisterExternallyReferencedObject(
         reinterpret_cast<internal::Object**>(FromVal(Traits::Get(&impl_, key))),
         reinterpret_cast<internal::Isolate*>(GetIsolate()));
diff --git a/include/v8-version-string.h b/include/v8-version-string.h
new file mode 100644
index 00000000..075282de
--- /dev/null
+++ b/include/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/include/v8-version.h b/include/v8-version.h
index eda966be..3bd8e041 100644
--- a/include/v8-version.h
+++ b/include/v8-version.h
@@ -9,9 +9,9 @@
 // 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 5
-#define V8_MINOR_VERSION 6
-#define V8_BUILD_NUMBER 326
-#define V8_PATCH_LEVEL 50
+#define V8_MINOR_VERSION 8
+#define V8_BUILD_NUMBER 283
+#define V8_PATCH_LEVEL 32
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)
diff --git a/include/v8.h b/include/v8.h
index 5348ba7e..baf44170 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -666,7 +666,7 @@ struct CopyablePersistentTraits {
 /**
  * A PersistentBase which allows copy and assignment.
  *
- * Copy, assignment and destructor bevavior is controlled by the traits
+ * Copy, assignment and destructor behavior is controlled by the traits
  * class M.
  *
  * Note: Persistent class hierarchy is subject to future changes.
@@ -867,8 +867,8 @@ class V8_EXPORT HandleScope {
 
   HandleScope(const HandleScope&) = delete;
   void operator=(const HandleScope&) = delete;
-  void* operator new(size_t size) = delete;
-  void operator delete(void*, size_t) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
 
  protected:
   V8_INLINE HandleScope() {}
@@ -919,8 +919,8 @@ class V8_EXPORT EscapableHandleScope : public HandleScope {
 
   EscapableHandleScope(const EscapableHandleScope&) = delete;
   void operator=(const EscapableHandleScope&) = delete;
-  void* operator new(size_t size) = delete;
-  void operator delete(void*, size_t) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
 
  private:
   internal::Object** Escape(internal::Object** escape_value);
@@ -934,8 +934,8 @@ class V8_EXPORT SealHandleScope {
 
   SealHandleScope(const SealHandleScope&) = delete;
   void operator=(const SealHandleScope&) = delete;
-  void* operator new(size_t size) = delete;
-  void operator delete(void*, size_t) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
 
  private:
   internal::Isolate* const isolate_;
@@ -961,29 +961,31 @@ class V8_EXPORT Data {
  */
 class ScriptOriginOptions {
  public:
-  V8_INLINE ScriptOriginOptions(bool is_embedder_debug_script = false,
-                                bool is_shared_cross_origin = false,
-                                bool is_opaque = false)
-      : flags_((is_embedder_debug_script ? kIsEmbedderDebugScript : 0) |
-               (is_shared_cross_origin ? kIsSharedCrossOrigin : 0) |
-               (is_opaque ? kIsOpaque : 0)) {}
+  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 &
-               (kIsEmbedderDebugScript | kIsSharedCrossOrigin | kIsOpaque)) {}
-  bool IsEmbedderDebugScript() const {
-    return (flags_ & kIsEmbedderDebugScript) != 0;
-  }
+               (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 {
-    kIsEmbedderDebugScript = 1,
-    kIsSharedCrossOrigin = 1 << 1,
-    kIsOpaque = 1 << 2
+    kIsSharedCrossOrigin = 1,
+    kIsOpaque = 1 << 1,
+    kIsWasm = 1 << 2,
+    kIsModule = 1 << 3
   };
   const int flags_;
 };
@@ -999,9 +1001,11 @@ class ScriptOrigin {
       Local<Integer> resource_column_offset = Local<Integer>(),
       Local<Boolean> resource_is_shared_cross_origin = Local<Boolean>(),
       Local<Integer> script_id = Local<Integer>(),
-      Local<Boolean> resource_is_embedder_debug_script = Local<Boolean>(),
       Local<Value> source_map_url = Local<Value>(),
-      Local<Boolean> resource_is_opaque = Local<Boolean>());
+      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;
@@ -1191,6 +1195,8 @@ class V8_EXPORT ScriptCompiler {
     // alive.
     V8_INLINE const CachedData* GetCachedData() const;
 
+    V8_INLINE const ScriptOriginOptions& GetResourceOptions() const;
+
     // Prevent copying.
     Source(const Source&) = delete;
     Source& operator=(const Source&) = delete;
@@ -1433,7 +1439,7 @@ class V8_EXPORT ScriptCompiler {
 
  private:
   static V8_WARN_UNUSED_RESULT MaybeLocal<UnboundScript> CompileUnboundInternal(
-      Isolate* isolate, Source* source, CompileOptions options, bool is_module);
+      Isolate* isolate, Source* source, CompileOptions options);
 };
 
 
@@ -1486,6 +1492,11 @@ class V8_EXPORT Message {
   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.
    */
@@ -1713,9 +1724,26 @@ class V8_EXPORT ValueSerializer {
     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);
+
+    /*
      * 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);
@@ -1757,7 +1785,7 @@ class V8_EXPORT ValueSerializer {
 
   /*
    * Marks an ArrayBuffer as havings its contents transferred out of band.
-   * Pass the corresponding JSArrayBuffer in the deserializing context to
+   * Pass the corresponding ArrayBuffer in the deserializing context to
    * ValueDeserializer::TransferArrayBuffer.
    */
   void TransferArrayBuffer(uint32_t transfer_id,
@@ -1766,8 +1794,19 @@ class V8_EXPORT ValueSerializer {
   /*
    * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
    */
-  void TransferSharedArrayBuffer(uint32_t transfer_id,
-                                 Local<SharedArrayBuffer> shared_array_buffer);
+  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.
@@ -1834,9 +1873,10 @@ class V8_EXPORT ValueDeserializer {
 
   /*
    * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
-   * transfer_id exists in the same namespace as unshared ArrayBuffer objects.
+   * The id is not necessarily in the same namespace as unshared ArrayBuffer
+   * objects.
    */
-  void TransferSharedArrayBuffer(uint32_t transfer_id,
+  void TransferSharedArrayBuffer(uint32_t id,
                                  Local<SharedArrayBuffer> shared_array_buffer);
 
   /*
@@ -1908,9 +1948,16 @@ class V8_EXPORT Value : public Data {
    */
   V8_INLINE bool IsNull() const;
 
-   /**
-   * Returns true if this value is true.
+  /**
+   * 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;
 
   /**
@@ -1920,7 +1967,6 @@ class V8_EXPORT Value : public Data {
 
   /**
    * Returns true if this value is a symbol or a string.
-   * This is an experimental feature.
    */
   bool IsName() const;
 
@@ -1932,7 +1978,6 @@ class V8_EXPORT Value : public Data {
 
   /**
    * Returns true if this value is a symbol.
-   * This is an experimental feature.
    */
   bool IsSymbol() const;
 
@@ -2004,7 +2049,6 @@ class V8_EXPORT Value : public Data {
 
   /**
    * Returns true if this value is a Symbol object.
-   * This is an experimental feature.
    */
   bool IsSymbolObject() const;
 
@@ -2025,19 +2069,16 @@ class V8_EXPORT Value : public Data {
 
   /**
    * Returns true if this value is a Generator function.
-   * This is an experimental feature.
    */
   bool IsGeneratorFunction() const;
 
   /**
    * Returns true if this value is a Generator object (iterator).
-   * This is an experimental feature.
    */
   bool IsGeneratorObject() const;
 
   /**
    * Returns true if this value is a Promise.
-   * This is an experimental feature.
    */
   bool IsPromise() const;
 
@@ -2073,85 +2114,66 @@ class V8_EXPORT Value : public Data {
 
   /**
    * Returns true if this value is an ArrayBuffer.
-   * This is an experimental feature.
    */
   bool IsArrayBuffer() const;
 
   /**
    * Returns true if this value is an ArrayBufferView.
-   * This is an experimental feature.
    */
   bool IsArrayBufferView() const;
 
   /**
    * Returns true if this value is one of TypedArrays.
-   * This is an experimental feature.
    */
   bool IsTypedArray() const;
 
   /**
    * Returns true if this value is an Uint8Array.
-   * This is an experimental feature.
    */
   bool IsUint8Array() const;
 
   /**
    * Returns true if this value is an Uint8ClampedArray.
-   * This is an experimental feature.
    */
   bool IsUint8ClampedArray() const;
 
   /**
    * Returns true if this value is an Int8Array.
-   * This is an experimental feature.
    */
   bool IsInt8Array() const;
 
   /**
    * Returns true if this value is an Uint16Array.
-   * This is an experimental feature.
    */
   bool IsUint16Array() const;
 
   /**
    * Returns true if this value is an Int16Array.
-   * This is an experimental feature.
    */
   bool IsInt16Array() const;
 
   /**
    * Returns true if this value is an Uint32Array.
-   * This is an experimental feature.
    */
   bool IsUint32Array() const;
 
   /**
    * Returns true if this value is an Int32Array.
-   * This is an experimental feature.
    */
   bool IsInt32Array() const;
 
   /**
    * Returns true if this value is a Float32Array.
-   * This is an experimental feature.
    */
   bool IsFloat32Array() const;
 
   /**
    * Returns true if this value is a Float64Array.
-   * This is an experimental feature.
    */
   bool IsFloat64Array() const;
 
   /**
-   * Returns true if this value is a SIMD Float32x4.
-   * This is an experimental feature.
-   */
-  bool IsFloat32x4() const;
-
-  /**
    * Returns true if this value is a DataView.
-   * This is an experimental feature.
    */
   bool IsDataView() const;
 
@@ -2244,11 +2266,12 @@ class V8_EXPORT Value : public Data {
 
   template <class T> V8_INLINE static Value* Cast(T* value);
 
-  Local<String> TypeOf(v8::Isolate*);
+  Local<String> TypeOf(Isolate*);
 
  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;
@@ -2291,9 +2314,10 @@ class V8_EXPORT Name : public Primitive {
    */
   int GetIdentityHash();
 
-  V8_INLINE static Name* Cast(v8::Value* obj);
+  V8_INLINE static Name* Cast(Value* obj);
+
  private:
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
@@ -2310,7 +2334,7 @@ class V8_EXPORT String : public Name {
   enum Encoding {
     UNKNOWN_ENCODING = 0x1,
     TWO_BYTE_ENCODING = 0x0,
-    ONE_BYTE_ENCODING = 0x4
+    ONE_BYTE_ENCODING = 0x8
   };
   /**
    * Returns the number of characters in this string.
@@ -2391,7 +2415,7 @@ class V8_EXPORT String : public Name {
   /**
    * A zero length string.
    */
-  V8_INLINE static v8::Local<v8::String> Empty(Isolate* isolate);
+  V8_INLINE static Local<String> Empty(Isolate* isolate);
 
   /**
    * Returns true if the string is external
@@ -2425,7 +2449,8 @@ class V8_EXPORT String : public Name {
     void operator=(const ExternalStringResourceBase&) = delete;
 
    private:
-    friend class v8::internal::Heap;
+    friend class internal::Heap;
+    friend class v8::String;
   };
 
   /**
@@ -2669,8 +2694,6 @@ class V8_EXPORT String : public Name {
 
 /**
  * A JavaScript symbol (ECMA-262 edition 6)
- *
- * This is an experimental feature. Use at your own risk.
  */
 class V8_EXPORT Symbol : public Name {
  public:
@@ -2695,14 +2718,15 @@ class V8_EXPORT Symbol : public Name {
   // Well-known symbols
   static Local<Symbol> GetIterator(Isolate* isolate);
   static Local<Symbol> GetUnscopables(Isolate* isolate);
+  static Local<Symbol> GetToPrimitive(Isolate* isolate);
   static Local<Symbol> GetToStringTag(Isolate* isolate);
   static Local<Symbol> GetIsConcatSpreadable(Isolate* isolate);
 
-  V8_INLINE static Symbol* Cast(v8::Value* obj);
+  V8_INLINE static Symbol* Cast(Value* obj);
 
  private:
   Symbol();
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
@@ -3695,7 +3719,7 @@ class V8_EXPORT Function : public Object {
   /**
    * Tells whether this function is builtin.
    */
-  bool IsBuiltin() const;
+  V8_DEPRECATED("this should no longer be used.", bool IsBuiltin() const);
 
   /**
    * Returns scriptId.
@@ -3720,10 +3744,15 @@ class V8_EXPORT Function : public Object {
 
 /**
  * An instance of the built-in Promise constructor (ES6 draft).
- * This API is experimental. Only works with --harmony flag.
  */
 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:
     /**
@@ -3780,6 +3809,17 @@ class V8_EXPORT Promise : public Object {
    */
   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);
 
  private:
@@ -3926,7 +3966,6 @@ enum class ArrayBufferCreationMode { kInternalized, kExternalized };
 
 /**
  * An instance of the built-in ArrayBuffer constructor (ES6 draft 15.13.5).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT ArrayBuffer : public Object {
  public:
@@ -3982,8 +4021,6 @@ class V8_EXPORT ArrayBuffer : public Object {
    *
    * The Data pointer of ArrayBuffer::Contents is always allocated with
    * Allocator::Allocate that is set via Isolate::CreateParams.
-   *
-   * This API is experimental and may change significantly.
    */
   class V8_EXPORT Contents { // NOLINT
    public:
@@ -4084,8 +4121,6 @@ class V8_EXPORT ArrayBuffer : public Object {
 /**
  * A base class for an instance of one of "views" over ArrayBuffer,
  * including TypedArrays and DataView (ES6 draft 15.13).
- *
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT ArrayBufferView : public Object {
  public:
@@ -4133,7 +4168,6 @@ class V8_EXPORT ArrayBufferView : public Object {
 /**
  * A base class for an instance of TypedArray series of constructors
  * (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT TypedArray : public ArrayBufferView {
  public:
@@ -4153,7 +4187,6 @@ class V8_EXPORT TypedArray : public ArrayBufferView {
 
 /**
  * An instance of Uint8Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Uint8Array : public TypedArray {
  public:
@@ -4171,7 +4204,6 @@ class V8_EXPORT Uint8Array : public TypedArray {
 
 /**
  * An instance of Uint8ClampedArray constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Uint8ClampedArray : public TypedArray {
  public:
@@ -4189,7 +4221,6 @@ class V8_EXPORT Uint8ClampedArray : public TypedArray {
 
 /**
  * An instance of Int8Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Int8Array : public TypedArray {
  public:
@@ -4207,7 +4238,6 @@ class V8_EXPORT Int8Array : public TypedArray {
 
 /**
  * An instance of Uint16Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Uint16Array : public TypedArray {
  public:
@@ -4225,7 +4255,6 @@ class V8_EXPORT Uint16Array : public TypedArray {
 
 /**
  * An instance of Int16Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Int16Array : public TypedArray {
  public:
@@ -4243,7 +4272,6 @@ class V8_EXPORT Int16Array : public TypedArray {
 
 /**
  * An instance of Uint32Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Uint32Array : public TypedArray {
  public:
@@ -4261,7 +4289,6 @@ class V8_EXPORT Uint32Array : public TypedArray {
 
 /**
  * An instance of Int32Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Int32Array : public TypedArray {
  public:
@@ -4279,7 +4306,6 @@ class V8_EXPORT Int32Array : public TypedArray {
 
 /**
  * An instance of Float32Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Float32Array : public TypedArray {
  public:
@@ -4297,7 +4323,6 @@ class V8_EXPORT Float32Array : public TypedArray {
 
 /**
  * An instance of Float64Array constructor (ES6 draft 15.13.6).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT Float64Array : public TypedArray {
  public:
@@ -4315,7 +4340,6 @@ class V8_EXPORT Float64Array : public TypedArray {
 
 /**
  * An instance of DataView constructor (ES6 draft 15.13.7).
- * This API is experimental and may change significantly.
  */
 class V8_EXPORT DataView : public ArrayBufferView {
  public:
@@ -4446,7 +4470,7 @@ class V8_EXPORT Date : public Object {
    */
   double ValueOf() const;
 
-  V8_INLINE static Date* Cast(v8::Value* obj);
+  V8_INLINE static Date* Cast(Value* obj);
 
   /**
    * Notification that the embedder has changed the time zone,
@@ -4463,7 +4487,7 @@ class V8_EXPORT Date : public Object {
   static void DateTimeConfigurationChangeNotification(Isolate* isolate);
 
  private:
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
@@ -4476,10 +4500,10 @@ class V8_EXPORT NumberObject : public Object {
 
   double ValueOf() const;
 
-  V8_INLINE static NumberObject* Cast(v8::Value* obj);
+  V8_INLINE static NumberObject* Cast(Value* obj);
 
  private:
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
@@ -4493,10 +4517,10 @@ class V8_EXPORT BooleanObject : public Object {
 
   bool ValueOf() const;
 
-  V8_INLINE static BooleanObject* Cast(v8::Value* obj);
+  V8_INLINE static BooleanObject* Cast(Value* obj);
 
  private:
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
@@ -4509,17 +4533,15 @@ class V8_EXPORT StringObject : public Object {
 
   Local<String> ValueOf() const;
 
-  V8_INLINE static StringObject* Cast(v8::Value* obj);
+  V8_INLINE static StringObject* Cast(Value* obj);
 
  private:
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
 /**
  * A Symbol object (ECMA-262 edition 6).
- *
- * This is an experimental feature. Use at your own risk.
  */
 class V8_EXPORT SymbolObject : public Object {
  public:
@@ -4527,10 +4549,10 @@ class V8_EXPORT SymbolObject : public Object {
 
   Local<Symbol> ValueOf() const;
 
-  V8_INLINE static SymbolObject* Cast(v8::Value* obj);
+  V8_INLINE static SymbolObject* Cast(Value* obj);
 
  private:
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
@@ -4580,10 +4602,10 @@ class V8_EXPORT RegExp : public Object {
    */
   Flags GetFlags() const;
 
-  V8_INLINE static RegExp* Cast(v8::Value* obj);
+  V8_INLINE static RegExp* Cast(Value* obj);
 
  private:
-  static void CheckCast(v8::Value* obj);
+  static void CheckCast(Value* obj);
 };
 
 
@@ -4600,8 +4622,11 @@ class V8_EXPORT External : public Value {
   static void CheckCast(v8::Value* obj);
 };
 
-
-#define V8_INTRINSICS_LIST(F) F(ArrayProto_values, array_values_iterator)
+#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)
 
 enum Intrinsic {
 #define V8_DECL_INTRINSIC(name, iname) k##name,
@@ -5144,7 +5169,11 @@ class V8_EXPORT FunctionTemplate : public Template {
   /** Get the InstanceTemplate. */
   Local<ObjectTemplate> InstanceTemplate();
 
-  /** Causes the function template to inherit from a parent function template.*/
+  /**
+   * 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);
 
   /**
@@ -5154,6 +5183,14 @@ class V8_EXPORT FunctionTemplate : public 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.
@@ -5611,9 +5648,9 @@ class V8_EXPORT Extension {  // NOLINT
             const char** deps = 0,
             int source_length = -1);
   virtual ~Extension() { }
-  virtual v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
-      v8::Isolate* isolate, v8::Local<v8::String> name) {
-    return v8::Local<v8::FunctionTemplate>();
+  virtual Local<FunctionTemplate> GetNativeFunctionTemplate(
+      Isolate* isolate, Local<String> name) {
+    return Local<FunctionTemplate>();
   }
 
   const char* name() const { return name_; }
@@ -5718,7 +5755,7 @@ 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> error);
+typedef void (*MessageCallback)(Local<Message> message, Local<Value> data);
 
 // --- Tracing ---
 
@@ -5787,6 +5824,27 @@ typedef void (*BeforeCallEnteredCallback)(Isolate*);
 typedef void (*CallCompletedCallback)(Isolate*);
 typedef void (*DeprecatedCallCompletedCallback)();
 
+/**
+ * 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,
@@ -5889,6 +5947,21 @@ typedef void (*FailedAccessCheckCallback)(Local<Object> target,
  */
 typedef bool (*AllowCodeGenerationFromStringsCallback)(Local<Context> context);
 
+// --- WASM compilation callbacks ---
+
+/**
+ * Callback to check if a buffer source may be compiled to WASM, given
+ * the compilation is attempted as a promise or not.
+ */
+
+typedef bool (*AllowWasmCompileCallback)(Isolate* isolate, Local<Value> source,
+                                         bool as_promise);
+
+typedef bool (*AllowWasmInstantiateCallback)(Isolate* isolate,
+                                             Local<Value> module_or_bytes,
+                                             MaybeLocal<Value> ffi,
+                                             bool as_promise);
+
 // --- Garbage Collection Callbacks ---
 
 /**
@@ -6249,17 +6322,33 @@ class V8_EXPORT EmbedderHeapTracer {
 };
 
 /**
- * Callback to the embedder used in SnapshotCreator to handle internal fields.
+ * Callback and supporting data used in SnapshotCreator to implement embedder
+ * logic to serialize internal fields.
  */
-typedef StartupData (*SerializeInternalFieldsCallback)(Local<Object> holder,
-                                                       int index);
+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;
+};
 
 /**
- * Callback to the embedder used to deserialize internal fields.
+ * Callback and supporting data used to implement embedder logic to deserialize
+ * internal fields.
  */
-typedef void (*DeserializeInternalFieldsCallback)(Local<Object> holder,
-                                                  int index,
-                                                  StartupData payload);
+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;
+};
 
 /**
  * Isolate represents an isolated instance of the V8 engine.  V8 isolates have
@@ -6284,7 +6373,7 @@ class V8_EXPORT Isolate {
           add_histogram_sample_callback(nullptr),
           array_buffer_allocator(nullptr),
           external_references(nullptr),
-          deserialize_internal_fields_callback(nullptr) {}
+          allow_atomics_wait(true) {}
 
     /**
      * The optional entry_hook allows the host application to provide the
@@ -6342,10 +6431,10 @@ class V8_EXPORT Isolate {
     intptr_t* external_references;
 
     /**
-     * Specifies an optional callback to deserialize internal fields. It
-     * should match the SerializeInternalFieldCallback used to serialize.
+     * Whether calling Atomics.wait (a function that may block) is allowed in
+     * this isolate.
      */
-    DeserializeInternalFieldsCallback deserialize_internal_fields_callback;
+    bool allow_atomics_wait;
   };
 
 
@@ -6481,12 +6570,25 @@ class V8_EXPORT Isolate {
     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);
 
@@ -6707,6 +6809,14 @@ class V8_EXPORT Isolate {
   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
@@ -6725,8 +6835,10 @@ class V8_EXPORT Isolate {
    * garbage collection types it is sufficient to provide object groups
    * for partially dependent handles only.
    */
-  template<typename T> void SetObjectGroupId(const Persistent<T>& object,
-                                             UniqueId id);
+  template <typename T>
+  V8_DEPRECATED("Use EmbedderHeapTracer",
+                void SetObjectGroupId(const Persistent<T>& object,
+                                      UniqueId id));
 
   /**
    * Allows the host application to declare implicit references from an object
@@ -6735,8 +6847,10 @@ class V8_EXPORT Isolate {
    * are removed. It is intended to be used in the before-garbage-collection
    * callback function.
    */
-  template<typename T> void SetReferenceFromGroup(UniqueId id,
-                                                  const Persistent<T>& child);
+  template <typename T>
+  V8_DEPRECATED("Use EmbedderHeapTracer",
+                void SetReferenceFromGroup(UniqueId id,
+                                           const Persistent<T>& child));
 
   /**
    * Allows the host application to declare implicit references from an object
@@ -6744,8 +6858,10 @@ class V8_EXPORT Isolate {
    * too. After each garbage collection, all implicit references are removed. It
    * is intended to be used in the before-garbage-collection callback function.
    */
-  template<typename T, typename S>
-  void SetReference(const Persistent<T>& parent, const Persistent<S>& child);
+  template <typename T, typename S>
+  V8_DEPRECATED("Use EmbedderHeapTracer",
+                void SetReference(const Persistent<T>& parent,
+                                  const Persistent<S>& child));
 
   typedef void (*GCCallback)(Isolate* isolate, GCType type,
                              GCCallbackFlags flags);
@@ -6888,6 +7004,12 @@ class V8_EXPORT Isolate {
           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.
    */
@@ -7021,6 +7143,23 @@ class V8_EXPORT Isolate {
   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.
    *
@@ -7085,13 +7224,23 @@ class V8_EXPORT Isolate {
       AllowCodeGenerationFromStringsCallback callback);
 
   /**
+   * Set the callback to invoke to check if wasm compilation from
+   * the specified object is allowed. By default, wasm compilation
+   * is allowed.
+   *
+   * Similar for instantiate.
+   */
+  void SetAllowWasmCompileCallback(AllowWasmCompileCallback callback);
+  void SetAllowWasmInstantiateCallback(AllowWasmInstantiateCallback 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.
+   * 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.
@@ -7103,6 +7252,21 @@ class V8_EXPORT Isolate {
                           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);
@@ -7598,10 +7762,23 @@ class V8_EXPORT SnapshotCreator {
   Isolate* GetIsolate();
 
   /**
-   * Add a context to be included in the snapshot blob.
+   * 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);
+  size_t AddContext(Local<Context> context,
+                    SerializeInternalFieldsCallback callback =
+                        SerializeInternalFieldsCallback());
 
   /**
    * Add a template to be included in the snapshot blob.
@@ -7614,12 +7791,10 @@ class V8_EXPORT SnapshotCreator {
    * This must not be called from within a handle scope.
    * \param function_code_handling whether to include compiled function code
    *        in the snapshot.
-   * \param callback to serialize embedder-set internal fields.
    * \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,
-                         SerializeInternalFieldsCallback callback = nullptr);
+  StartupData CreateBlob(FunctionCodeHandling function_code_handling);
 
   // Disallow copying and assigning.
   SnapshotCreator(const SnapshotCreator&) = delete;
@@ -7825,21 +8000,21 @@ class V8_EXPORT TryCatch {
    * UseAfterReturn is enabled, then the address returned will be the address
    * of the C++ try catch handler itself.
    */
-  static void* JSStackComparableAddress(v8::TryCatch* handler) {
+  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) = delete;
-  void operator delete(void*, size_t) = delete;
+  void* operator new(size_t size);
+  void operator delete(void*, size_t);
 
  private:
   void ResetInternal();
 
-  v8::internal::Isolate* isolate_;
-  v8::TryCatch* next_;
+  internal::Isolate* isolate_;
+  TryCatch* next_;
   void* exception_;
   void* message_obj_;
   void* js_stack_comparable_address_;
@@ -7849,7 +8024,7 @@ class V8_EXPORT TryCatch {
   bool rethrow_ : 1;
   bool has_terminated_ : 1;
 
-  friend class v8::internal::Isolate;
+  friend class internal::Isolate;
 };
 
 
@@ -7922,10 +8097,30 @@ class V8_EXPORT Context {
       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 internal_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 internal_fields_deserializer =
+          DeserializeInternalFieldsCallback(),
       ExtensionConfiguration* extensions = nullptr,
-      MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
       MaybeLocal<Value> global_object = MaybeLocal<Value>());
 
   /**
@@ -7976,7 +8171,7 @@ class V8_EXPORT Context {
   void Exit();
 
   /** Returns an isolate associated with a current context. */
-  v8::Isolate* GetIsolate();
+  Isolate* GetIsolate();
 
   /**
    * The field at kDebugIdIndex is reserved for V8 debugger implementation.
@@ -8308,10 +8503,10 @@ class Internals {
   static const int kFixedArrayHeaderSize = 2 * kApiPointerSize;
   static const int kContextHeaderSize = 2 * kApiPointerSize;
   static const int kContextEmbedderDataIndex = 5;
-  static const int kFullStringRepresentationMask = 0x07;
-  static const int kStringEncodingMask = 0x4;
+  static const int kFullStringRepresentationMask = 0x0f;
+  static const int kStringEncodingMask = 0x8;
   static const int kExternalTwoByteRepresentationTag = 0x02;
-  static const int kExternalOneByteRepresentationTag = 0x06;
+  static const int kExternalOneByteRepresentationTag = 0x0a;
 
   static const int kIsolateEmbedderDataOffset = 0 * kApiPointerSize;
   static const int kExternalMemoryOffset = 4 * kApiPointerSize;
@@ -8336,11 +8531,11 @@ class Internals {
   static const int kNodeIsIndependentShift = 3;
   static const int kNodeIsActiveShift = 4;
 
-  static const int kJSObjectType = 0xbc;
-  static const int kJSApiObjectType = 0xbb;
+  static const int kJSApiObjectType = 0xb9;
+  static const int kJSObjectType = 0xba;
   static const int kFirstNonstringType = 0x80;
-  static const int kOddballType = 0x83;
-  static const int kForeignType = 0x87;
+  static const int kOddballType = 0x82;
+  static const int kForeignType = 0x86;
 
   static const int kUndefinedOddballKind = 5;
   static const int kNullOddballKind = 3;
@@ -8856,17 +9051,17 @@ ScriptOrigin::ScriptOrigin(Local<Value> resource_name,
                            Local<Integer> resource_column_offset,
                            Local<Boolean> resource_is_shared_cross_origin,
                            Local<Integer> script_id,
-                           Local<Boolean> resource_is_embedder_debug_script,
                            Local<Value> source_map_url,
-                           Local<Boolean> resource_is_opaque)
+                           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_embedder_debug_script.IsEmpty() &&
-                   resource_is_embedder_debug_script->IsTrue(),
-               !resource_is_shared_cross_origin.IsEmpty() &&
+      options_(!resource_is_shared_cross_origin.IsEmpty() &&
                    resource_is_shared_cross_origin->IsTrue(),
-               !resource_is_opaque.IsEmpty() && resource_is_opaque->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) {}
 
@@ -8915,14 +9110,16 @@ const ScriptCompiler::CachedData* ScriptCompiler::Source::GetCachedData()
   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, v8::Local<Data> value) {
-  Set(v8::String::NewFromUtf8(isolate, name, NewStringType::kNormal)
+void Template::Set(Isolate* isolate, const char* name, Local<Data> value) {
+  Set(String::NewFromUtf8(isolate, name, NewStringType::kInternalized)
           .ToLocalChecked(),
       value);
 }
@@ -9056,6 +9253,23 @@ bool Value::QuickIsNull() const {
   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
@@ -9531,7 +9745,7 @@ template<typename T>
 void Isolate::SetObjectGroupId(const Persistent<T>& object,
                                UniqueId id) {
   TYPE_CHECK(Value, T);
-  SetObjectGroupId(reinterpret_cast<v8::internal::Object**>(object.val_), id);
+  SetObjectGroupId(reinterpret_cast<internal::Object**>(object.val_), id);
 }
 
 
@@ -9539,8 +9753,7 @@ template<typename T>
 void Isolate::SetReferenceFromGroup(UniqueId id,
                                     const Persistent<T>& object) {
   TYPE_CHECK(Value, T);
-  SetReferenceFromGroup(id,
-                        reinterpret_cast<v8::internal::Object**>(object.val_));
+  SetReferenceFromGroup(id, reinterpret_cast<internal::Object**>(object.val_));
 }
 
 
@@ -9549,8 +9762,8 @@ void Isolate::SetReference(const Persistent<T>& parent,
                            const Persistent<S>& child) {
   TYPE_CHECK(Object, T);
   TYPE_CHECK(Value, S);
-  SetReference(reinterpret_cast<v8::internal::Object**>(parent.val_),
-               reinterpret_cast<v8::internal::Object**>(child.val_));
+  SetReference(reinterpret_cast<internal::Object**>(parent.val_),
+               reinterpret_cast<internal::Object**>(child.val_));
 }
 
 
@@ -9627,14 +9840,14 @@ void V8::SetFatalErrorHandler(FatalErrorCallback callback) {
 void V8::RemoveGCPrologueCallback(GCCallback callback) {
   Isolate* isolate = Isolate::GetCurrent();
   isolate->RemoveGCPrologueCallback(
-      reinterpret_cast<v8::Isolate::GCCallback>(callback));
+      reinterpret_cast<Isolate::GCCallback>(callback));
 }
 
 
 void V8::RemoveGCEpilogueCallback(GCCallback callback) {
   Isolate* isolate = Isolate::GetCurrent();
   isolate->RemoveGCEpilogueCallback(
-      reinterpret_cast<v8::Isolate::GCCallback>(callback));
+      reinterpret_cast<Isolate::GCCallback>(callback));
 }
 
 void V8::TerminateExecution(Isolate* isolate) { isolate->TerminateExecution(); }