[Bindings] Create and use V8 context snapshots

third_party/WebKit/Source/platform/bindings/V8PerContextData.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 112 matching lines @@
   // Garbage collected classes that use V8PerContextData to hold an instance
   // should subclass Data, and use addData / clearData / getData to manage the
   // instance.
   class PLATFORM_EXPORT Data : public GarbageCollectedMixin {};
 
   void AddData(const char* key, Data*);
   void ClearData(const char* key);
   Data* GetData(const char* key);
 
  private:
+  // V8SnapshotUtil can access on wrapper_boilerplates_ and constructor_map_.
+  friend class V8SnapshotUtil;

[Yuki, 2017/06/20 14:20:11]

Can you remove this?

[peria, 2017/06/21 07:19:16]

Done.

+
   V8PerContextData(v8::Local<v8::Context>);
 
   v8::Local<v8::Object> CreateWrapperFromCacheSlowCase(const WrapperTypeInfo*);
   v8::Local<v8::Function> ConstructorForTypeSlowCase(const WrapperTypeInfo*);
 
   v8::Isolate* isolate_;
 
   // For each possible type of wrapper, we keep a boilerplate object.
   // The boilerplate is used to create additional wrappers of the same type.
   typedef V8GlobalValueMap<const WrapperTypeInfo*, v8::Object, v8::kNotWeak>
@@ skipping 18 matching lines @@
   // This is owned by a static hash map in V8DOMActivityLogger.
   V8DOMActivityLogger* activity_logger_;
 
   using DataMap = PersistentHeapHashMap<const char*, Member<Data>>;
   DataMap data_map_;
 };
 
 }  // namespace blink
 
 #endif  // V8PerContextData_h