Add missing IWYU message_loop.h includes.

chrome/browser/autofill/autofill_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 <stddef.h>
 
 #include <memory>
 #include <string>
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/memory/ref_counted.h"
+#include "base/message_loop/message_loop.h"
 #include "base/rand_util.h"
 #include "base/run_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/autofill/personal_data_manager_factory.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 783 matching lines @@
 IN_PROC_BROWSER_TEST_F(AutofillTest,
                        DISABLED_MergeAggregatedDuplicatedProfiles) {
   int num_of_profiles =
       AggregateProfilesIntoAutofillPrefs("dataset_duplicated_profiles.txt");
 
   ASSERT_GT(num_of_profiles,
             static_cast<int>(personal_data_manager()->GetProfiles().size()));
 }
 
 }  // namespace autofill