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

chrome/browser/errorpage_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/bind.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/net/url_request_mock_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
@@ skipping 85 matching lines @@
         NULL,
         num_navigations);
     if (direction == HISTORY_NAVIGATE_BACK) {
       chrome::GoBack(browser(), CURRENT_TAB);
     } else if (direction == HISTORY_NAVIGATE_FORWARD) {
       chrome::GoForward(browser(), CURRENT_TAB);
     } else {
       FAIL();
     }
     test_navigation_observer.WaitForObservation(
-        base::Bind(&ui_test_utils::RunMessageLoop),
+        base::Bind(&content::RunMessageLoop),
         base::Bind(&MessageLoop::Quit,
                    base::Unretained(MessageLoopForUI::current())));
 
     EXPECT_EQ(title_watcher.WaitAndGetTitle(), ASCIIToUTF16(expected_title));
   }
 };
 
 // See crbug.com/109669
 #if defined(USE_AURA)
 #define MAYBE_DNSError_Basic DISABLED_DNSError_Basic
@@ skipping 116 matching lines @@
 }
 
 // Checks that the Link Doctor is not loaded when we receive an actual 404 page.
 IN_PROC_BROWSER_TEST_F(ErrorPageTest, Page404) {
   NavigateToURLAndWaitForTitle(
       URLRequestMockHTTPJob::GetMockUrl(
           FilePath(FILE_PATH_LITERAL("page404.html"))),
       "SUCCESS",
       1);
 }