Revert r21117 as it caused reliability failures....

chrome/common/ipc_channel_proxy.h

 // Copyright (c) 2006-2008 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 CHROME_COMMON_IPC_CHANNEL_PROXY_H__
 #define CHROME_COMMON_IPC_CHANNEL_PROXY_H__
 
 #include <vector>
 
 #include "base/ref_counted.h"
@@ skipping 99 matching lines @@
   virtual bool Send(Message* message);
 
   // Used to intercept messages as they are received on the background thread.
   //
   // Ordinarily, messages sent to the ChannelProxy are routed to the matching
   // listener on the worker thread.  This API allows code to intercept messages
   // before they are sent to the worker thread.
   void AddFilter(MessageFilter* filter);
   void RemoveFilter(MessageFilter* filter);
 
-  // Called to clear the pointer to the IPC message loop when it's going away.
-  void ClearIPCMessageLoop();
-
 #if defined(OS_POSIX)
   // Calls through to the underlying channel's methods.
   // TODO(playmobil): For now this is only implemented in the case of
   // create_pipe_now = true, we need to figure this out for the latter case.
   int GetClientFileDescriptor() const;
 #endif  // defined(OS_POSIX)
 
  protected:
   class Context;
   // A subclass uses this constructor if it needs to add more information
   // to the internal state.  If create_pipe_now is true, the pipe is created
   // immediately.  Otherwise it's created on the IO thread.
   ChannelProxy(const std::string& channel_id, Channel::Mode mode,
                MessageLoop* ipc_thread_loop, Context* context,
                bool create_pipe_now);
 
   // Used internally to hold state that is referenced on the IPC thread.
   class Context : public base::RefCountedThreadSafe<Context>,
                   public Channel::Listener {
    public:
     Context(Channel::Listener* listener, MessageFilter* filter,
             MessageLoop* ipc_thread);
     virtual ~Context() { }
-    void ClearIPCMessageLoop() { ipc_message_loop_ = NULL; }
     MessageLoop* ipc_message_loop() const { return ipc_message_loop_; }
     const std::string& channel_id() const { return channel_id_; }
 
     // Dispatches a message on the listener thread.
     void OnDispatchMessage(const Message& message);
 
    protected:
     // IPC::Channel::Listener methods:
     virtual void OnMessageReceived(const Message& message);
     virtual void OnChannelConnected(int32 peer_pid);
@@ skipping 47 matching lines @@
 
   // By maintaining this indirection (ref-counted) to our internal state, we
   // can safely be destroyed while the background thread continues to do stuff
   // that involves this data.
   scoped_refptr<Context> context_;
 };
 
 }  // namespace IPC
 
 #endif  // CHROME_COMMON_IPC_CHANNEL_PROXY_H__