Remove message_loop_helpers.h and update the includes to point to the new location.

chrome/browser/chromeos/login/screen_locker.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 CHROME_BROWSER_CHROMEOS_LOGIN_SCREEN_LOCKER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREEN_LOCKER_H_
 #pragma once
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop_helpers.h"
+#include "base/sequenced_task_runner_helpers.h"
 #include "base/time.h"
 #include "chrome/browser/chromeos/login/help_app_launcher.h"
 #include "chrome/browser/chromeos/login/login_status_consumer.h"
 #include "chrome/browser/chromeos/login/screen_locker_delegate.h"
 #include "ui/base/accelerators/accelerator.h"
 
 namespace chromeos {
 
 class Authenticator;
 class LoginFailure;
@@ skipping 120 matching lines @@
   // Delegate to forward all login status events to.
   // Tests can use this to receive login status events.
   LoginStatusConsumer* login_status_consumer_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenLocker);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREEN_LOCKER_H_