bindings: Adds virtual ScriptWrappable::wrap method.

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 "config.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 
+#include "bindings/core/v8/DOMDataStore.h"
+#include "bindings/core/v8/V8DOMWrapper.h"
+
 namespace blink {
 
 #if COMPILER(MSVC)
 __declspec(align(4))
 #endif
 struct SameSizeAsScriptWrappableBase { };
 
 COMPILE_ASSERT(sizeof(ScriptWrappableBase) <= sizeof(SameSizeAsScriptWrappableBase), ScriptWrappableBase_should_stay_small);
 
 struct SameSizeAsScriptWrappable : public ScriptWrappableBase {
     virtual ~SameSizeAsScriptWrappable() { }
     uintptr_t m_wrapperOrTypeInfo;
 };
 
 COMPILE_ASSERT(sizeof(ScriptWrappable) <= sizeof(SameSizeAsScriptWrappable), ScriptWrappable_should_stay_small);
 
+v8::Handle<v8::Object> ScriptWrappable::wrap(v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
+{
+    ASSERT(!DOMDataStore::containsWrapperNonTemplate(this, isolate));
+
+    const WrapperTypeInfo* wrapperType = wrapperTypeInfo();
+
+    // Might be a XXXConstructor::wrapperTypeInfo instead of an
+    // XXX::wrapperTypeInfo. These will both have the same object de-ref
+    // functions, though, so use that as the basis of the check.
+    RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(typeInfo()->derefObjectFunction == wrapperType->derefObjectFunction);

[haraken, 2014/08/29 05:24:04]

Do we need to check this? I guess we can drop this check now that the wrap
function is guaranteed to be a wrap function of the correct type (C++ compiler
guarantees it).

[Yuki, 2014/09/01 06:06:39]

Done.

+
+    v8::Handle<v8::Object> wrapper = V8DOMWrapper::createWrapper(creationContext, wrapperType, toInternalPointer(), isolate);
+    if (UNLIKELY(wrapper.IsEmpty()))
+        return wrapper;
+
+    wrapperType->installConditionallyEnabledProperties(wrapper, isolate);
+    wrapperType->refObject(toInternalPointer());
+    V8DOMWrapper::associateObjectWithWrapperNonTemplate(this, wrapperType, wrapper, isolate, WrapperConfiguration::Dependent);

[haraken, 2014/08/29 05:24:04]

It looks wrong to always use WrapperConfiguration::Dependent. Independent DOM
objects need to use WrapperConfiguration::Independent.

If you use WrapperConfiguration::Dependent for independent DOM objects, it won't
break anything but delay timing when the DOM objects are collected by V8 GC (and
thus regress performance).

I think we should add a test case to verify that independent DOM objects are
corrected in an expected GC round. A follow-up CL is fine.

[Yuki, 2014/09/01 06:06:39]

Nice catch!  Thanks for pointing this out.  As you already know, I'm now working
on this issue in a separate CL.

+    return wrapper;
+}
+
 } // namespace blink