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

content/child/quota_message_filter.h

Index: content/child/quota_message_filter.h
diff --git a/content/child/quota_message_filter.h b/content/child/quota_message_filter.h
index eba63137dfe451b038281ae31f87d8008a9c7e95..eabff1bf8ca727a74c5d682714fe60436018f1ae 100644
--- a/content/child/quota_message_filter.h
+++ b/content/child/quota_message_filter.h
@@ -8,7 +8,7 @@
 #include <map>
 
 #include "base/synchronization/lock.h"
-#include "ipc/ipc_channel_proxy.h"
+#include "content/child/child_message_filter.h"
 
 namespace base {
 class MessageLoopProxy;
@@ -18,13 +18,10 @@ namespace content {
 
 class ThreadSafeSender;
 
-class QuotaMessageFilter : public IPC::ChannelProxy::MessageFilter {
+class QuotaMessageFilter : public ChildMessageFilter {
  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.
@@ -37,9 +34,12 @@ class QuotaMessageFilter : public IPC::ChannelProxy::MessageFilter {
   virtual ~QuotaMessageFilter();
 
  private:
-  typedef std::map<int, int> RequestIdToThreadId;
+  // ChildMessageFilter implementation:
+  virtual base::TaskRunner* OverrideTaskRunnerForMessage(
+      const IPC::Message& msg) OVERRIDE;
+  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
-  void DispatchMessage(const IPC::Message& msg);
+  typedef std::map<int, int> RequestIdToThreadId;
 
   scoped_refptr<base::MessageLoopProxy> main_thread_loop_proxy_;
   scoped_refptr<ThreadSafeSender> thread_safe_sender_;