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

chrome/browser/extensions/extension_function_test_utils.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 "chrome/browser/extensions/extension_function_test_utils.h"
 
 #include <string>
 
 #include "base/file_path.h"
 #include "base/json/json_reader.h"
@@ skipping 206 matching lines @@
   function->set_dispatcher(dispatcher.AsWeakPtr());
 
   function->set_profile(browser->profile());
   function->set_include_incognito(flags & INCLUDE_INCOGNITO);
   function->Run();
 
   // If the RunImpl of |function| didn't already call SendResponse, run the
   // message loop until they do.
   if (!response_delegate.HasResponse()) {
     response_delegate.set_should_post_quit(true);
-    ui_test_utils::RunMessageLoop();
+    content::RunMessageLoop();
   }
 
   EXPECT_TRUE(response_delegate.HasResponse());
   return response_delegate.GetResponse();
 }
 
 } // namespace extension_function_test_utils