[gin] Introduce Wrappable::GetObjectTemplate

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 75378063de872e58d4da5085cd102ad7046abc5c..164cbb82ca9867e40a3a658f4e1dffb58e8b58cc 100644
--- a/mojo/apps/js/bindings/waiting_callback.cc
+++ b/mojo/apps/js/bindings/waiting_callback.cc
@@ -4,8 +4,8 @@
 
 #include "mojo/apps/js/bindings/waiting_callback.h"
 
+#include "gin/object_template_builder.h"
 #include "gin/per_context_data.h"
-#include "gin/per_isolate_data.h"
 
 namespace mojo {
 namespace js {
@@ -37,14 +37,9 @@ gin::Handle<WaitingCallback> WaitingCallback::Create(
   return gin::CreateHandle(isolate, new WaitingCallback(isolate, callback));
 }
 
-void WaitingCallback::EnsureRegistered(v8::Isolate* isolate) {
-  gin::PerIsolateData* data = gin::PerIsolateData::From(isolate);
-  if (!data->GetObjectTemplate(&WaitingCallback::kWrapperInfo).IsEmpty()) {
-    return;
-  }
-  v8::Handle<v8::ObjectTemplate> templ = v8::ObjectTemplate::New(isolate);
-  templ->SetInternalFieldCount(gin::kNumberOfInternalFields);
-  data->SetObjectTemplate(&WaitingCallback::kWrapperInfo, templ);
+v8::Local<v8::ObjectTemplate> WaitingCallback::GetObjectTemplate(
+    v8::Isolate* isolate) {
+  return gin::ObjectTemplateBuilder(isolate).Build();
 }
 
 void WaitingCallback::OnHandleReady(MojoResult result) {