Minor clean up in DBusClient, DBusThreadManager, and FakeDBusThreadManager code.

chromeos/dbus/fake_dbus_thread_manager.h

 // 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.
 
 #ifndef CHROMEOS_DBUS_FAKE_DBUS_THREAD_MANAGER_H_
 #define CHROMEOS_DBUS_FAKE_DBUS_THREAD_MANAGER_H_
 
-#include <string>
-
 #include "base/logging.h"
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 
 namespace dbus {
 class Bus;
 class ObjectPath;
 }  // namespace dbus
 
@@ skipping 146 matching lines @@
   scoped_ptr<UpdateEngineClient> update_engine_client_;
 
   scoped_ptr<PowerPolicyController> power_policy_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeDBusThreadManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_FAKE_DBUS_THREAD_MANAGER_H_