Decouple IPC::MessageFilter from IPC::Channel

components/tracing/child_trace_message_filter.h

 // Copyright (c) 2012 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 COMPONENTS_TRACING_CHILD_TRACE_MESSAGE_FILTER_H_
 #define COMPONENTS_TRACING_CHILD_TRACE_MESSAGE_FILTER_H_
 
 #include "base/bind.h"
 #include "base/memory/ref_counted_memory.h"
 #include "ipc/message_filter.h"
 
 namespace base {
 class MessageLoopProxy;
 }
 
 namespace tracing {
 
 // This class sends and receives trace messages on child processes.
 class ChildTraceMessageFilter : public IPC::MessageFilter {
  public:
   explicit ChildTraceMessageFilter(base::MessageLoopProxy* ipc_message_loop);
 
   // IPC::MessageFilter implementation.
-  virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE;
+  virtual void OnFilterAdded(IPC::Sender* sender) OVERRIDE;
   virtual void OnFilterRemoved() OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
  protected:
   virtual ~ChildTraceMessageFilter();
 
  private:
   // Message handlers.
   void OnBeginTracing(const std::string& category_filter_str,
                       base::TimeTicks browser_time,
@@ skipping 12 matching lines @@
 
   // Callback from trace subsystem.
   void OnTraceDataCollected(
       const scoped_refptr<base::RefCountedString>& events_str_ptr,
       bool has_more_events);
 
   void OnMonitoringTraceDataCollected(
       const scoped_refptr<base::RefCountedString>& events_str_ptr,
       bool has_more_events);
 
-  IPC::Channel* channel_;
+  IPC::Sender* sender_;
   base::MessageLoopProxy* ipc_message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildTraceMessageFilter);
 };
 
 }  // namespace tracing
 
 #endif  // COMPONENTS_TRACING_CHILD_TRACE_MESSAGE_FILTER_H_