Add missing IWYU message_loop.h includes.

content/browser/service_worker/service_worker_job_unittest.cc

 // Copyright 2014 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 <stdint.h>
 #include <tuple>
 
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/message_loop/message_loop.h"
 #include "base/optional.h"
 #include "base/run_loop.h"
 #include "base/test/test_simple_task_runner.h"
 #include "base/time/time.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/service_worker/embedded_worker_registry.h"
 #include "content/browser/service_worker/embedded_worker_status.h"
 #include "content/browser/service_worker/embedded_worker_test_helper.h"
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
@@ skipping 1779 matching lines @@
   // should not be promoted to ACTIVATED because failure occur
   // during shutdown.
   runner->RunUntilIdle();
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(new_version.get(), registration->active_version());
   EXPECT_EQ(ServiceWorkerVersion::ACTIVATING, new_version->status());
   registration->RemoveListener(update_helper);
 }
 
 }  // namespace content