Use a direct include of the message_loop header in chrome/test/, chrome/tools/, chrome/utility/.

chrome/utility/importer/firefox_importer_unittest_utils_mac.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/utility/importer/firefox_importer_unittest_utils.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/test/test_timeouts.h"
 #include "chrome/common/importer/firefox_importer_utils.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_descriptors.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_multiprocess_test.h"
 #include "ipc/ipc_switches.h"
 #include "testing/multiprocess_func_list.h"
 
@@ skipping 248 matching lines @@
 
   IPC::Channel channel(kTestChannelID, IPC::Channel::MODE_CLIENT, &listener);
   CHECK(channel.Connect());
   listener.SetSender(&channel);
 
   // run message loop
   base::MessageLoop::current()->Run();
 
   return 0;
 }