[gin] Add a v8::Platform implementation to allow for v8 posting tasks

gin/per_isolate_data.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_PER_ISOLATE_DATA_H_
 #define GIN_PER_ISOLATE_DATA_H_
 
 #include <map>
 
 #include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
 #include "gin/gin_export.h"
 #include "gin/public/wrapper_info.h"
 #include "v8/include/v8.h"
 
+namespace base {
+class MessageLoopProxy;
+}
+
 namespace gin {
 
 class IndexedPropertyInterceptor;
 class NamedPropertyInterceptor;
 class WrappableBase;
 
 // There is one instance of PerIsolateData per v8::Isolate managed by Gin. This
 // class stores all the Gin-related data that varies per isolate.
 class GIN_EXPORT PerIsolateData {
  public:
@@ skipping 28 matching lines @@
                                        IndexedPropertyInterceptor* interceptor);
   void ClearNamedPropertyInterceptor(WrappableBase* base,
                                      NamedPropertyInterceptor* interceptor);
 
   IndexedPropertyInterceptor* GetIndexedPropertyInterceptor(
       WrappableBase* base);
   NamedPropertyInterceptor* GetNamedPropertyInterceptor(WrappableBase* base);
 
   v8::Isolate* isolate() { return isolate_; }
   v8::ArrayBuffer::Allocator* allocator() { return allocator_; }
+  base::MessageLoopProxy* message_loop_proxy() {
+    return message_loop_proxy_.get();
+  }
 
  private:
   typedef std::map<
       WrapperInfo*, v8::Eternal<v8::ObjectTemplate> > ObjectTemplateMap;
   typedef std::map<
       WrapperInfo*, v8::Eternal<v8::FunctionTemplate> > FunctionTemplateMap;
   typedef std::map<WrappableBase*, IndexedPropertyInterceptor*>
       IndexedPropertyInterceptorMap;
   typedef std::map<WrappableBase*, NamedPropertyInterceptor*>
       NamedPropertyInterceptorMap;
 
   // PerIsolateData doesn't actually own |isolate_|. Instead, the isolate is
   // owned by the IsolateHolder, which also owns the PerIsolateData.
   v8::Isolate* isolate_;
   v8::ArrayBuffer::Allocator* allocator_;
   ObjectTemplateMap object_templates_;
   FunctionTemplateMap function_templates_;
   IndexedPropertyInterceptorMap indexed_interceptors_;
   NamedPropertyInterceptorMap named_interceptors_;
+  scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
 
   DISALLOW_COPY_AND_ASSIGN(PerIsolateData);
 };
 
 }  // namespace gin
 
 #endif  // GIN_PER_ISOLATE_DATA_H_