Use a direct include of the message_loop header in content/, part 3.

content/public/test/download_test_observer.cc

 // 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.
 
 #include "content/public/test/download_test_observer.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/stl_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_url_parameters.h"
 #include "content/public/test/test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
 
 DownloadUpdatedObserver::DownloadUpdatedObserver(
@@ skipping 420 matching lines @@
     base::MessageLoopForUI::current()->Quit();
 }
 
 const DownloadUrlParameters::OnStartedCallback
     DownloadTestItemCreationObserver::callback() {
   return base::Bind(
       &DownloadTestItemCreationObserver::DownloadItemCreationCallback, this);
 }
 
 }  // namespace content