chromeos: Remove dead power manager code.

chrome/browser/chromeos/power/output_observer.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 CHROME_BROWSER_CHROMEOS_POWER_OUTPUT_OBSERVER_H_
-#define CHROME_BROWSER_CHROMEOS_POWER_OUTPUT_OBSERVER_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "chromeos/dbus/power_manager_client.h"
-
-namespace chromeos {
-
-// This observer listens for when video outputs have been turned off so that the
-// corresponding CRTCs can be disabled to force the connected output off.
-// TODO(derat): Remove this class after powerd is calling the method
-// exported by DisplayPowerServiceProvider instead.
-class OutputObserver : public PowerManagerClient::Observer {
- public:
-  // This class registers/unregisters itself as an observer in ctor/dtor.
-  OutputObserver();
-  virtual ~OutputObserver();
-
- private:
-  // PowerManagerClient::Observer implementation.
-  virtual void ScreenPowerSet(bool power_on, bool all_displays) OVERRIDE;
-
-  DISALLOW_COPY_AND_ASSIGN(OutputObserver);
-};
-
-}  // namespace chromeos
-
-#endif  // CHROME_BROWSER_CHROMEOS_POWER_OUTPUT_OBSERVER_H_