Move ui_test_utils::RunMessageLoop to test_utils so that it can be reused by content_browsertests.

chrome/browser/task_manager/task_manager_browsertest_util.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 "base/message_loop.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/task_manager/task_manager.h"
 #include "chrome/browser/task_manager/task_manager_browsertest_util.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 48 matching lines @@
   model->AddObserver(&observer);
 
   // Checks that the condition has not been satisfied yet.
   // This check has to be placed after the installation of the observer,
   // because resources may change before that.
   if (model->ResourceCount() == target_count) {
     model->RemoveObserver(&observer);
     return;
   }
 
-  ui_test_utils::RunMessageLoop();
+  content::RunMessageLoop();
   model->RemoveObserver(&observer);
 }
 
 // static
 void TaskManagerBrowserTestUtil::ShowTaskManagerAndWaitForReady(
     Browser* browser) {
 #if defined(USE_AURA)
   content::WindowedNotificationObserver observer(
       chrome::NOTIFICATION_TASK_MANAGER_WINDOW_READY,
       content::Source<TaskManagerModel>(TaskManager::GetInstance()->model()));
   browser->window()->ShowTaskManager();
   observer.Wait();
 #else
   browser->window()->ShowTaskManager();
 #endif  // defined(USE_AURA)
 }