Add missing IWYU message_loop.h includes.

content/gpu/gpu_child_thread.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 "content/gpu/gpu_child_thread.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
 #include "base/threading/thread_checker.h"
 #include "build/build_config.h"
 #include "content/child/child_process.h"
 #include "content/common/field_trial_recorder.mojom.h"
 #include "content/gpu/gpu_service_factory.h"
 #include "content/public/common/connection_filter.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/service_manager_connection.h"
 #include "content/public/common/service_names.mojom.h"
@@ skipping 275 matching lines @@
 void GpuChildThread::BindServiceFactoryRequest(
     const service_manager::BindSourceInfo& source_info,
     service_manager::mojom::ServiceFactoryRequest request) {
   DVLOG(1) << "GPU: Binding service_manager::mojom::ServiceFactoryRequest";
   DCHECK(service_factory_);
   service_factory_bindings_.AddBinding(service_factory_.get(),
                                        std::move(request));
 }
 
 }  // namespace content