Gin: Add support for binding JS methods to C++ instance methods.

gin/wrappable.h

 // Copyright 2013 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.
 
 #ifndef GIN_WRAPPABLE_H_
 #define GIN_WRAPPABLE_H_
 
 #include "base/memory/ref_counted.h"
 #include "gin/converter.h"
 #include "gin/public/wrapper_info.h"
@@ skipping 64 matching lines @@
   static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val,
                      Wrappable** out);
 };
 
 template<typename T>
 struct WrappableConverter {
   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate, T* val) {
     return Converter<Wrappable*>::ToV8(isolate, val);
   }
   static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val, T** out) {
-    Wrappable* wrappable = 0;

[Aaron Boodman, 2013/12/04 07:05:29]

We use NULL, not zero in Chrome code

[abarth-chromium, 2013/12/04 16:27:55]

Yep!

+    Wrappable* wrappable = NULL;
     if (!Converter<Wrappable*>::FromV8(isolate, val, &wrappable)
         || wrappable->GetWrapperInfo() != &T::kWrapperInfo)
       return false;
     // Currently we require that you unwrap to the exact runtime type of the
     // wrapped object.
     // TODO(abarth): Support unwrapping to a base class.
     *out = static_cast<T*>(wrappable);
     return true;
   }
 };
 
 }  // namespace gin
 
 #endif  // GIN_WRAPPABLE_H_