Decouple IPC::MessageFilter from IPC::Channel

content/public/browser/browser_message_filter.h

Index: content/public/browser/browser_message_filter.h
diff --git a/content/public/browser/browser_message_filter.h b/content/public/browser/browser_message_filter.h
index f1334b941c0c7779692a527799eaa5b97df4c3f8..81f06a90343aaab3123e03ee7a0e4d35541fb92f 100644
--- a/content/public/browser/browser_message_filter.h
+++ b/content/public/browser/browser_message_filter.h
@@ -39,7 +39,7 @@ class CONTENT_EXPORT BrowserMessageFilter
 
   // These match the corresponding IPC::MessageFilter methods and are always
   // called on the IO thread.
-  virtual void OnFilterAdded(IPC::Channel* channel) {}
+  virtual void OnFilterAdded(IPC::Sender* sender) {}
   virtual void OnFilterRemoved() {}
   virtual void OnChannelClosing() {}
   virtual void OnChannelConnected(int32 peer_pid) {}
@@ -123,7 +123,7 @@ class CONTENT_EXPORT BrowserMessageFilter
   // child class does in its OnDestruct method.
   Internal* internal_;
 
-  IPC::Channel* channel_;
+  IPC::Sender* sender_;
   base::ProcessId peer_pid_;
 
   std::vector<uint32> message_classes_to_filter_;