Implement Worker-MainThread bridge for FileWriter in Chrome

content/child/fileapi/webfilewriter_impl.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 CONTENT_CHILD_FILEAPI_WEBFILEWRITER_IMPL_H_
 #define CONTENT_CHILD_FILEAPI_WEBFILEWRITER_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "webkit/renderer/fileapi/webfilewriter_base.h"
 
 namespace content {
 
 // An implementation of WebFileWriter for use in chrome renderers and workers.
 class WebFileWriterImpl : public fileapi::WebFileWriterBase,
                           public base::SupportsWeakPtr<WebFileWriterImpl> {
  public:
-  WebFileWriterImpl(const GURL& path, WebKit::WebFileWriterClient* client);
+  WebFileWriterImpl(const GURL& path,
+                    WebKit::WebFileWriterClient* client,
+                    base::MessageLoopProxy* main_thread_loop);
   virtual ~WebFileWriterImpl();
 
  protected:
   // WebFileWriterBase overrides
   virtual void DoTruncate(const GURL& path, int64 offset) OVERRIDE;
   virtual void DoWrite(const GURL& path, const GURL& blob_url,
                        int64 offset) OVERRIDE;
   virtual void DoCancel() OVERRIDE;
 
  private:
-  class CallbackDispatcher;
-  int request_id_;
+  class WriterBridge;
+
+  void RunOnMainThread(const base::Closure& closure);
+
+  scoped_refptr<base::MessageLoopProxy> main_thread_loop_;
+  scoped_refptr<WriterBridge> bridge_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_FILEAPI_WEBFILEWRITER_IMPL_H_