Gin: Make it easier to implement Wrappable

gin/function_template.h.pump

 $$ This is a pump file for generating file templates.  Pump is a python
 $$ script that is part of the Google Test suite of utilities.  Description
 $$ can be found here:
 $$
 $$ http://code.google.com/p/googletest/wiki/PumpManual
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 #ifndef GIN_FUNCTION_TEMPLATE_H_
 #define GIN_FUNCTION_TEMPLATE_H_
 
@@ skipping 40 matching lines @@
 
 // CallbackHolder and CallbackHolderBase are used to pass a base::Callback from
 // CreateFunctionTemplate through v8 (via v8::FunctionTemplate) to 
 // DispatchToCallback, where it is invoked.
 //
 // v8::FunctionTemplate only supports passing void* as data so how do we know
 // when to delete the base::Callback? That's where CallbackHolderBase comes in.
 // It inherits from Wrappable, which delete itself when both (a) the refcount
 // via base::RefCounted has dropped to zero, and (b) there are no more
 // JavaScript references in V8.
+//
+// TODO(aa): Do we still need the separate base class?
 class CallbackHolderBase : public Wrappable {
- public:
-  virtual WrapperInfo* GetWrapperInfo() OVERRIDE;
-  static WrapperInfo kWrapperInfo;
  protected:
   virtual ~CallbackHolderBase() {}
 };
 
 template<typename Sig>
 class CallbackHolder : public CallbackHolderBase {
  public:
   CallbackHolder(const base::Callback<Sig>& callback, int flags)
       : callback(callback), flags(flags) {}
   base::Callback<Sig> callback;
@@ skipping 125 matching lines @@
   gin::Handle<HolderT> holder = CreateHandle(
       isolate, new HolderT(callback, callback_flags));
   return v8::FunctionTemplate::New(
       &internal::Dispatcher<Sig>::DispatchToCallback,
       ConvertToV8<internal::CallbackHolderBase*>(isolate, holder.get()));
 }
 
 }  // namespace gin
 
 #endif  // GIN_FUNCTION_TEMPLATE_H_