Gin: Make it easier to implement Wrappable

mojo/apps/js/bindings/waiting_callback.cc

Index: mojo/apps/js/bindings/waiting_callback.cc
diff --git a/mojo/apps/js/bindings/waiting_callback.cc b/mojo/apps/js/bindings/waiting_callback.cc
index a1d230c174b0e0c0b03b36b66457c154fa7ec5fe..9a8eead6c361aa32e52d9f76d22be06cf55bbc24 100644
--- a/mojo/apps/js/bindings/waiting_callback.cc
+++ b/mojo/apps/js/bindings/waiting_callback.cc
@@ -35,19 +35,16 @@ gin::Handle<WaitingCallback> WaitingCallback::Create(
   return gin::CreateHandle(isolate, new WaitingCallback(isolate, callback));
 }
 
-gin::WrapperInfo WaitingCallback::kWrapperInfo = { gin::kEmbedderNativeGin };
-
-gin::WrapperInfo* WaitingCallback::GetWrapperInfo() {
-  return &kWrapperInfo;
-}
-
 void WaitingCallback::EnsureRegistered(v8::Isolate* isolate) {
   gin::PerIsolateData* data = gin::PerIsolateData::From(isolate);
-  if (!data->GetObjectTemplate(&kWrapperInfo).IsEmpty())
+  if (!data->GetObjectTemplate(
+          &gin::WrappableTraits<WaitingCallback>::kWrapperInfo).IsEmpty()) {
     return;
+  }
   v8::Handle<v8::ObjectTemplate> templ = v8::ObjectTemplate::New(isolate);
   templ->SetInternalFieldCount(gin::kNumberOfInternalFields);
-  data->SetObjectTemplate(&kWrapperInfo, templ);
+  data->SetObjectTemplate(&gin::WrappableTraits<WaitingCallback>::kWrapperInfo,
+                          templ);
 }
 
 void WaitingCallback::OnHandleReady(MojoResult result) {