[ES6 modules] Introduce Modulator "module map settings object"

third_party/WebKit/Source/bindings/core/v8/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 30 matching lines @@
 #include "wtf/Allocator.h"
 #include "wtf/HashMap.h"
 #include "wtf/Vector.h"
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/AtomicStringHash.h"
 #include <memory>
 #include <v8.h>
 
 namespace blink {
 
+class Modulator;
 class V8DOMActivityLogger;
 class V8PerContextData;
 
 enum V8ContextEmbedderDataField {
   v8ContextPerContextDataIndex =
       static_cast<int>(gin::kPerContextDataStartIndex + gin::kEmbedderBlink),
 };
 
 class CORE_EXPORT V8PerContextData final {
   USING_FAST_MALLOC(V8PerContextData);
@@ skipping 25 matching lines @@
 
   v8::Local<v8::Object> prototypeForType(const WrapperTypeInfo*);
 
   void addCustomElementBinding(std::unique_ptr<V0CustomElementBinding>);
 
   V8DOMActivityLogger* activityLogger() const { return m_activityLogger; }
   void setActivityLogger(V8DOMActivityLogger* activityLogger) {
     m_activityLogger = activityLogger;
   }
 
+  Modulator* modulator() const { return m_modulator.get(); }
+  void setModulator(Modulator*);

[haraken, 2017/01/18 06:55:56]

Instead of eagerly setting a modulator, can we instantiate the modulator lazily?
i.e., instantiate the modulator on the first access to modulator().

[kouhei (in TOK), 2017/01/18 07:07:10]

Yes. This is what we are going to do.

+  void clearModulator();
+
  private:
   V8PerContextData(v8::Local<v8::Context>);
 
   v8::Local<v8::Object> createWrapperFromCacheSlowCase(const WrapperTypeInfo*);
   v8::Local<v8::Function> constructorForTypeSlowCase(const WrapperTypeInfo*);
 
   v8::Isolate* m_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>
       WrapperBoilerplateMap;
   WrapperBoilerplateMap m_wrapperBoilerplates;
 
   typedef V8GlobalValueMap<const WrapperTypeInfo*, v8::Function, v8::kNotWeak>
       ConstructorMap;
   ConstructorMap m_constructorMap;
 
   std::unique_ptr<gin::ContextHolder> m_contextHolder;
 
   ScopedPersistent<v8::Context> m_context;
   ScopedPersistent<v8::Value> m_errorPrototype;
 
   typedef Vector<std::unique_ptr<V0CustomElementBinding>>
       V0CustomElementBindingList;
   V0CustomElementBindingList m_customElementBindings;
 
   // This is owned by a static hash map in V8DOMActivityLogger.
   V8DOMActivityLogger* m_activityLogger;
+
+  Persistent<Modulator> m_modulator;
 };
 
 }  // namespace blink
 
 #endif  // V8PerContextData_h