Add missing IWYU message_loop.h includes.

components/autofill/core/browser/personal_data_manager_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 "components/autofill/core/browser/personal_data_manager.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <list>
 #include <map>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/guid.h"
 #include "base/i18n/time_formatting.h"
 #include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/test/histogram_tester.h"
 #include "base/test/simple_test_clock.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "components/autofill/core/browser/autofill_experiments.h"
 #include "components/autofill/core/browser/autofill_metrics.h"
@@ skipping 6382 matching lines @@
   // to the converted address.
   EXPECT_EQ(profiles[0]->guid(),
             personal_data_->GetCreditCards()[0]->billing_address_id());
   // Make sure that the billing address id of the new server card still refers
   // to the converted address.
   EXPECT_EQ(profiles[0]->guid(),
             personal_data_->GetCreditCards()[1]->billing_address_id());
 }
 
 }  // namespace autofill