Decouple IPC::MessageFilter from IPC::Channel

ipc/message_filter.h

 // Copyright 2014 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 IPC_MESSAGE_FILTER_H_
 #define IPC_MESSAGE_FILTER_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "ipc/ipc_export.h"
 
 namespace IPC {
 
-class Channel;
+class Sender;
 class Message;
 
 // A class that receives messages on the thread where the IPC channel is
 // running.  It can choose to prevent the default action for an IPC message.
 class IPC_EXPORT MessageFilter
     : public base::RefCountedThreadSafe<MessageFilter> {
  public:
   MessageFilter();
 
   // Called on the background thread to provide the filter with access to the
   // channel.  Called when the IPC channel is initialized or when AddFilter
   // is called if the channel is already initialized.
-  virtual void OnFilterAdded(Channel* channel);
+  virtual void OnFilterAdded(Sender* sender);
 
   // Called on the background thread when the filter has been removed from
   // the ChannelProxy and when the Channel is closing.  After a filter is
   // removed, it will not be called again.
   virtual void OnFilterRemoved();
 
   // Called to inform the filter that the IPC channel is connected and we
   // have received the internal Hello message from the peer.
   virtual void OnChannelConnected(int32 peer_pid);
 
@@ skipping 19 matching lines @@
  protected:
   virtual ~MessageFilter();
 
  private:
   friend class base::RefCountedThreadSafe<MessageFilter>;
 };
 
 }  // namespace IPC
 
 #endif  // IPC_MESSAGE_FILTER_H_