bindings: Fixes perf regression by crrev.com/646523004.

Source/bindings/templates/interface.h

 // 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.
 
 // This file has been auto-generated by {{code_generator}}. DO NOT MODIFY!
 
 #ifndef {{v8_class}}_h
 #define {{v8_class}}_h
 
 {% filter conditional(conditional_string) %}
@@ skipping 170 matching lines @@
     static v8::Handle<v8::Object> createWrapper({{pass_cpp_type}}, v8::Handle<v8::Object> creationContext, v8::Isolate*);
     {% endif %}
     {% if has_partial_interface %}
 
 private:
     static InstallTemplateFunction install{{v8_class}}TemplateFunction;
     {% endif %}
 };
 
 {% if has_custom_to_v8 %}
 v8::Handle<v8::Value> toV8({{cpp_class}}*, v8::Handle<v8::Object> creationContext, v8::Isolate*);

[haraken, 2014/11/01 22:45:50]

Can we rename this to toV8Custom (for consistency with wrapCustom)? A follow-up
CL is fine.

[Yuki, 2014/11/04 05:48:17]

Unlike wrap/wrapCustom, toV8 is used as a public API, so it would be better to
keep the same name.  Or we can add a new toV8Custom as the following.

toV8(...) {
  return toV8Custom(...);
}

toV8Custom(...) {
  // implementation
}

 
+{% if interface_name != 'EventTarget' %}
+{# EventTarget has custom toV8 just because Window has custom toV8. So it is not
+   really necessary for EventTarget and its subclasses except for Window to call
+   custom toV8 function in v8SetReturnValue. Especially Node and its subclasses
+   are performance sensitive, so they should call optimized versions of
+   v8SetReturnValue defined in bindings/core/v8/V8Binding.h. #}
 template<typename CallbackInfo>
 inline void v8SetReturnValue(const CallbackInfo& callbackInfo, {{cpp_class}}* impl)
 {
     v8SetReturnValue(callbackInfo, toV8(impl, callbackInfo.Holder(), callbackInfo.GetIsolate()));
 }
 
 template<typename CallbackInfo>
 inline void v8SetReturnValueForMainWorld(const CallbackInfo& callbackInfo, {{cpp_class}}* impl)
 {
      v8SetReturnValue(callbackInfo, toV8(impl, callbackInfo.Holder(), callbackInfo.GetIsolate()));
 }
 
 template<typename CallbackInfo>
 inline void v8SetReturnValueFast(const CallbackInfo& callbackInfo, {{cpp_class}}* impl, const ScriptWrappable*)
 {
      v8SetReturnValue(callbackInfo, toV8(impl, callbackInfo.Holder(), callbackInfo.GetIsolate()));
 }
 
+{% endif %}{# interface_name != 'EventTarget' #}
 {% elif not is_script_wrappable %}
 v8::Handle<v8::Object> wrap({{cpp_class}}* impl, v8::Handle<v8::Object> creationContext, v8::Isolate*);
 
 inline v8::Handle<v8::Value> toV8({{cpp_class}}* impl, v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     if (UNLIKELY(!impl))
         return v8::Null(isolate);
     v8::Handle<v8::Value> wrapper = DOMDataStore::getWrapperNonTemplate(impl, isolate);
     if (!wrapper.IsEmpty())
         return wrapper;
@@ skipping 43 matching lines @@
 
 {% endif %}{# has_custom_to_v8 #}
 {% if has_event_constructor %}
 bool initialize{{cpp_class}}({{cpp_class}}Init&, const Dictionary&, ExceptionState&, const v8::FunctionCallbackInfo<v8::Value>& info, const String& = "");
 
 {% endif %}
 } // namespace blink
 {% endfilter %}
 
 #endif // {{v8_class}}_h