Prevent unused-variable warnings in the CrOS build with gcc 4.6.

chrome/browser/chromeos/login/image_decoder.cc

 // Copyright (c) 2011 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 "chrome/browser/chromeos/login/image_decoder.h"
 
 #include "base/bind.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/chrome_utility_messages.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 22 matching lines @@
 }
 
 bool ImageDecoder::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ImageDecoder, message)
     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_DecodeImage_Succeeded,
                         OnDecodeImageSucceeded)
     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_DecodeImage_Failed,
                         OnDecodeImageFailed)
     IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP_EX()
+  IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void ImageDecoder::OnDecodeImageSucceeded(const SkBitmap& decoded_image) {
   DCHECK(BrowserThread::CurrentlyOn(target_thread_id_));
   if (delegate_)
     delegate_->OnImageDecoded(this, decoded_image);
 }
 
 void ImageDecoder::OnDecodeImageFailed() {
   DCHECK(BrowserThread::CurrentlyOn(target_thread_id_));
   if (delegate_)
     delegate_->OnDecodeImageFailed(this);
 }
 
 void ImageDecoder::DecodeImageInSandbox(
     const std::vector<unsigned char>& image_data) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   UtilityProcessHost* utility_process_host =
       new UtilityProcessHost(this,
                              target_thread_id_);
   utility_process_host->Send(new ChromeUtilityMsg_DecodeImage(image_data));
 }
 
 }  // namespace chromeos