Add missing IWYU message_loop.h includes.

components/browser_sync/profile_sync_service_typed_url_unittest.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 <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/browser_sync/abstract_profile_sync_service_test.h"
 #include "components/browser_sync/test_profile_sync_service.h"
 #include "components/history/core/browser/history_backend.h"
 #include "components/history/core/browser/history_backend_client.h"
@@ skipping 1006 matching lines @@
   SendNotificationURLsModified(changed_urls);
 
   history::URLRows new_sync_entries;
   GetTypedUrlsFromSyncDB(&new_sync_entries);
 
   // The change should be ignored.
   ASSERT_EQ(0U, new_sync_entries.size());
 }
 
 }  // namespace browser_sync