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

gin/per_isolate_data.cc

 // 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.
 
 #include "base/logging.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "gin/per_isolate_data.h"
 #include "gin/public/gin_embedders.h"
 
 using v8::ArrayBuffer;
 using v8::Eternal;
 using v8::Isolate;
 using v8::Local;
 using v8::Object;
 using v8::FunctionTemplate;
 using v8::ObjectTemplate;
 
 namespace gin {
 
 PerIsolateData::PerIsolateData(Isolate* isolate,
                                ArrayBuffer::Allocator* allocator)
-    : isolate_(isolate), allocator_(allocator) {
+    : isolate_(isolate),
+      allocator_(allocator),
+      message_loop_proxy_(base::MessageLoopProxy::current()) {
   isolate_->SetData(kEmbedderNativeGin, this);
 }
 
 PerIsolateData::~PerIsolateData() {
   isolate_->SetData(kEmbedderNativeGin, NULL);
 }
 
 PerIsolateData* PerIsolateData::From(Isolate* isolate) {
   return static_cast<PerIsolateData*>(isolate->GetData(kEmbedderNativeGin));
 }
@@ skipping 68 matching lines @@
 NamedPropertyInterceptor* PerIsolateData::GetNamedPropertyInterceptor(
     WrappableBase* base) {
   NamedPropertyInterceptorMap::iterator it = named_interceptors_.find(base);
   if (it != named_interceptors_.end())
     return it->second;
   else
     return NULL;
 }
 
 }  // namespace gin