Add missing IWYU message_loop.h includes.

services/device/battery/battery_status_manager_linux.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 "services/device/battery/battery_status_manager_linux.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <limits>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
 #include "dbus/object_path.h"
 #include "dbus/object_proxy.h"
 #include "dbus/property.h"
@@ skipping 584 matching lines @@
   return manager;
 }
 
 // static
 std::unique_ptr<BatteryStatusManager> BatteryStatusManager::Create(
     const BatteryStatusService::BatteryUpdateCallback& callback) {
   return base::MakeUnique<BatteryStatusManagerLinux>(callback);
 }
 
 }  // namespace device