Adds support for ArrayBufferContents with external buffer.

third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl

 {% extends 'interface_base.cpp.tmpl' %}
 
 {% set has_prepare_prototype_and_interface_object =
     unscopables or has_conditional_attributes_on_prototype or
     methods | conditionally_exposed(is_partial) %}
 {% set prepare_prototype_and_interface_object_func =
     '%s::preparePrototypeAndInterfaceObject' % v8_class
     if has_prepare_prototype_and_interface_object
     else 'nullptr' %}
 
@@ skipping 763 matching lines @@
   if (v8buffer->IsExternal()) {
     const WrapperTypeInfo* wrapperTypeInfo = toWrapperTypeInfo(object);
     CHECK(wrapperTypeInfo);
     CHECK_EQ(wrapperTypeInfo->ginEmbedder, gin::kEmbedderBlink);
     return toScriptWrappable(object)->toImpl<{{cpp_class}}>();
   }
 
   // Transfer the ownership of the allocated memory to an {{interface_name}} without
   // copying.
   v8::{{interface_name}}::Contents v8Contents = v8buffer->Externalize();
-  WTF::ArrayBufferContents contents(v8Contents.Data(), v8Contents.ByteLength(), WTF::ArrayBufferContents::{% if interface_name == 'ArrayBuffer' %}Not{% endif %}Shared);
+  WTF::ArrayBufferContents::DataHandle data(v8Contents.Data(), WTF::ArrayBufferContents::freeMemory);
+  WTF::ArrayBufferContents contents(std::move(data), v8Contents.ByteLength(), WTF::ArrayBufferContents::{% if interface_name == 'ArrayBuffer' %}Not{% endif %}Shared);
   {{cpp_class}}* buffer = {{cpp_class}}::create(contents);
   v8::Local<v8::Object> associatedWrapper = buffer->associateWithWrapper(v8::Isolate::GetCurrent(), buffer->wrapperTypeInfo(), object);
   DCHECK(associatedWrapper == object);
 
   return buffer;
 }
 
 {% elif interface_name == 'ArrayBufferView' %}
 {{cpp_class}}* V8ArrayBufferView::toImpl(v8::Local<v8::Object> object) {
   DCHECK(object->IsArrayBufferView());
@@ skipping 97 matching lines @@
 }
 
 {% for method in methods if method.overloads and method.overloads.has_partial_overloads %}
 void {{v8_class}}::register{{method.name | blink_capitalize}}MethodForPartialInterface(void (*method)(const v8::FunctionCallbackInfo<v8::Value>&)) {
   {{cpp_class}}V8Internal::{{method.name}}MethodForPartialInterface = method;
 }
 
 {% endfor %}
 {% endif %}
 {% endblock %}