Use a direct include of the message_loop header in chrome/browser/, part 7.

chrome/browser/managed_mode/managed_user_registration_service_unittest.cc

 // Copyright 2013 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 <string>
 
 #include "base/bind.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/managed_mode/managed_user_refresh_token_fetcher.h"
 #include "chrome/browser/managed_mode/managed_user_registration_service.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_pref_service_syncable.h"
 #include "content/public/browser/browser_thread.h"
 #include "google_apis/gaia/google_service_auth_error.h"
@@ skipping 360 matching lines @@
   StartInitialSync();
   service()->Register(ManagedUserRegistrationInfo(ASCIIToUTF16("Mike")),
       GetRegistrationCallback());
   EXPECT_EQ(1u, prefs()->GetDictionary(prefs::kManagedUsers)->size());
   service()->StopSyncing(MANAGED_USERS);
   EXPECT_EQ(0u, prefs()->GetDictionary(prefs::kManagedUsers)->size());
   EXPECT_TRUE(received_callback());
   EXPECT_EQ(GoogleServiceAuthError::REQUEST_CANCELED, error().state());
   EXPECT_EQ(std::string(), token());
 }