Add ChildMessageFilter, a base class for renderer/worker cross-thread MessageFilter

content/child/quota_message_filter.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_QUOTA_MESSAGE_FILTER_H_
 #define CONTENT_CHILD_QUOTA_MESSAGE_FILTER_H_
 
 #include <map>
 
 #include "base/synchronization/lock.h"
-#include "ipc/ipc_channel_proxy.h"
-
-namespace base {
-class MessageLoopProxy;
-}
+#include "content/child/cross_thread_message_filter.h"
 
 namespace content {
 
 class ThreadSafeSender;
 
-class QuotaMessageFilter : public IPC::ChannelProxy::MessageFilter {
+class QuotaMessageFilter : public CrossThreadMessageFilter {
  public:
   explicit QuotaMessageFilter(ThreadSafeSender* thread_safe_sender);
 
-  // IPC::Listener implementation.
-  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
-
   // Generates a new request_id, registers { request_id, thread_id } map to
   // the message filter and returns the request_id.
   // This method can be called on any thread.
   int GenerateRequestID(int thread_id);
 
   // Clears all requests from the thread_id.
   void ClearThreadRequests(int thread_id);
 
  protected:
   virtual ~QuotaMessageFilter();
 
  private:
+  // CrossThreadMessageFilter implementation:
+  virtual bool OverrideThreadIDForMessage(const IPC::Message& msg,
+                                          int* thread_id) OVERRIDE;
+  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
+
   typedef std::map<int, int> RequestIdToThreadId;
 
-  void DispatchMessage(const IPC::Message& msg);
-
-  scoped_refptr<base::MessageLoopProxy> main_thread_loop_proxy_;
   scoped_refptr<ThreadSafeSender> thread_safe_sender_;
 
   base::Lock request_id_map_lock_;
   RequestIdToThreadId request_id_map_;
   int next_request_id_;
 
   DISALLOW_COPY_AND_ASSIGN(QuotaMessageFilter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_QUOTA_MESSAGE_FILTER_H_