Revert 276939 "Decouple IPC::MessageFilter from IPC::Channel"

content/child/child_histogram_message_filter.h

Index: content/child/child_histogram_message_filter.h
===================================================================
--- content/child/child_histogram_message_filter.h	(revision 278168)
+++ content/child/child_histogram_message_filter.h	(working copy)
@@ -24,7 +24,7 @@
   ChildHistogramMessageFilter();
 
   // IPC::MessageFilter implementation.
-  virtual void OnFilterAdded(IPC::Sender* sender) OVERRIDE;
+  virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE;
   virtual void OnFilterRemoved() OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
@@ -42,7 +42,7 @@
   // Send only a delta to what we have already sent.
   void UploadAllHistograms(int sequence_number);
 
-  IPC::Sender* sender_;
+  IPC::Channel* channel_;
 
   scoped_refptr<base::MessageLoopProxy> io_message_loop_;