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

chrome/browser/extensions/app_notification_browsertest.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/command_line.h"
 #include "chrome/browser/extensions/app_notify_channel_setup.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 45 matching lines @@
   AppNotifyChannelSetup::SetInterceptorForTests(&interceptor);
 
   const extensions::Extension* app =
       LoadExtension(test_data_dir_.AppendASCII("app_notifications"));
   ASSERT_TRUE(app != NULL);
 
   application_launch::OpenApplication(application_launch::LaunchParams(
           browser()->profile(), app, extension_misc::LAUNCH_TAB,
           NEW_FOREGROUND_TAB));
   if (!interceptor.was_called())
-    ui_test_utils::RunMessageLoop();
+    content::RunMessageLoop();
   EXPECT_TRUE(interceptor.was_called());
 
   ExtensionService* service = browser()->profile()->GetExtensionService();
   extensions::ExtensionPrefs* prefs = service->extension_prefs();
   std::string saved_id = prefs->GetAppNotificationClientId(app->id());
   EXPECT_EQ(kExpectedClientId, saved_id);
 }