Cleanup: Remove unneeded forward declarations from chrome/browser/chromeos.

chrome/browser/chromeos/dbus/sensors_client.h

 // Copyright (c) 2011 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 CHROME_BROWSER_CHROMEOS_DBUS_SENSORS_CLIENT_H_
 #define CHROME_BROWSER_CHROMEOS_DBUS_SENSORS_CLIENT_H_
 
 #include "base/basictypes.h"
 
 namespace dbus {
 class Bus;
-class ObjectProxy;
-class Signal;
 }  // namespace
 
 namespace chromeos {
 
 // Creates and manages a dbus signal receiver for device orientation changes,
 // and eventually receives data for other motion-related sensors.
 class SensorsClient {
  public:
   virtual ~SensorsClient();
 
   // Creates the instance.
   static SensorsClient* Create(dbus::Bus* bus);
 
  protected:
   // Create() should be used instead.
   SensorsClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SensorsClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_DBUS_SENSORS_CLIENT_H_