Attempt four at landing the "histogram.h removed from message_loop.h" patch.

ipc/ipc_channel_proxy.cc

 // 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.
 
 #include "base/message_loop.h"
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
 #include "base/thread.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "ipc/ipc_logging.h"
 #include "ipc/ipc_message_utils.h"
 
 namespace IPC {
 
 //------------------------------------------------------------------------------
 
 // This task ensures the message is deleted if the task is deleted without
@@ skipping 289 matching lines @@
 int ChannelProxy::GetClientFileDescriptor() const {
   Channel *channel = context_.get()->channel_;
   DCHECK(channel); // Channel must have been created first.
   return channel->GetClientFileDescriptor();
 }
 #endif
 
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC