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

content/browser/worker_host/test/worker_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/file_path.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/stringprintf.h"
 #include "base/string_util.h"
@@ skipping 296 matching lines @@
         BrowserThread::UI, FROM_HERE, MessageLoop::QuitClosure());
   }
 
   bool WaitForWorkerProcessCount(int count) {
     int cur_process_count;
     for (int i = 0; i < 100; ++i) {
       BrowserThread::PostTask(
           BrowserThread::IO, FROM_HERE,
           base::Bind(&CountWorkerProcesses, &cur_process_count));
 
-      base::RunLoop run_loop;
-      content::RunThisRunLoop(&run_loop);
+      content::RunMessageLoop();
       if (cur_process_count == count)
         return true;
 
       // Sometimes the worker processes can take a while to shut down on the
       // bots, so use a longer timeout period to avoid spurious failures.
       base::PlatformThread::Sleep(TestTimeouts::action_max_timeout() / 100);
     }
 
     EXPECT_EQ(cur_process_count, count);
     return false;
@@ skipping 167 matching lines @@
 
   // First window has hit its limit. Now launch second window which creates
   // the same worker that was queued in the first window, to ensure it gets
   // connected to the first window too.
   query = StringPrintf("?id=%d", max_workers_per_tab);
   url = GetTestURL("single_shared_worker.html", query);
   content::NavigateToURL(CreateBrowser(), url);
 
   ASSERT_TRUE(WaitForWorkerProcessCount(max_workers_per_tab + 1));
 }