Introduce infrastructure for tracing ScriptWrappables.

third_party/WebKit/Source/bindings/core/v8/ScriptWrappable.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "bindings/core/v8/ScriptWrappable.h"
 
 #include "bindings/core/v8/DOMDataStore.h"
+#include "bindings/core/v8/ScriptWrappableHeapTracer.h"
 #include "bindings/core/v8/V8DOMWrapper.h"
 
 namespace blink {
 
 struct SameSizeAsScriptWrappable {
     virtual ~SameSizeAsScriptWrappable() { }
     v8::Persistent<v8::Object> m_wrapper;
 };
 
 static_assert(sizeof(ScriptWrappable) <= sizeof(SameSizeAsScriptWrappable), "ScriptWrappable should stay small");
@@ skipping 10 matching lines @@
 
     wrapperTypeInfo->installConditionallyEnabledProperties(wrapper, isolate);
     return associateWithWrapper(isolate, wrapperTypeInfo, wrapper);
 }
 
 v8::Local<v8::Object> ScriptWrappable::associateWithWrapper(v8::Isolate* isolate, const WrapperTypeInfo* wrapperTypeInfo, v8::Local<v8::Object> wrapper)
 {
     return V8DOMWrapper::associateObjectWithWrapper(isolate, this, wrapperTypeInfo, wrapper);
 }
 
+void ScriptWrappable::markWrapper(v8::Isolate* isolate) const

[haraken, 2016/04/18 04:35:41]

This method looks redundant. The caller sites of this method should just call
ScriptWrappableHeapTracer::markWrapper.

(Below I'm suggesting renaming it to
ScriptWrappableHeapTracer::markWrappersInAllWorlds.)

[Marcel Hlopko, 2016/04/18 11:45:35]

I agree, in this form the method is useless. I changed it so it actually marks
its wrapper, if contains one. See the comment above for longer discussion.

+{
+    ScriptWrappableHeapTracer::markWrapper(this, isolate);
+}
+
 } // namespace blink