chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/display/display_preferences.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_DISPLAY_DISPLAY_PREFERENCES_H_
 #define CHROME_BROWSER_CHROMEOS_DISPLAY_DISPLAY_PREFERENCES_H_
 
 #include <stdint.h>
 
 #include "third_party/cros_system_api/dbus/service_constants.h"
 #include "ui/display/manager/display_layout.h"
 
 class PrefRegistrySimple;
 
-namespace gfx {
-class Insets;
-}
-
 namespace chromeos {
 
 // Registers the prefs associated with display settings and stored
 // into Local State.
 void RegisterDisplayLocalStatePrefs(PrefRegistrySimple* registry);
 
 // Stores the current displays prefereces (both primary display id and
 // dispay layout).
 void StoreDisplayPrefs();
 
 // If there is an internal display, stores |rotation_lock| along with the
 // current rotation of the internal display. Otherwise no data is stored.
 void StoreDisplayRotationPrefs(bool rotation_lock);
 
 // Load display preferences from Local Store. |first_run_after_boot| is used
 // determine if a certain preference should be applied at boot time or
 // restart.
 void LoadDisplayPreferences(bool first_run_after_boot);
 
 // Stores the display layout for given display pairs for tests.
 void StoreDisplayLayoutPrefForTest(const display::DisplayIdList& list,
                                    const display::DisplayLayout& layout);
 
 // Stores the given |power_state| for tests.
 void StoreDisplayPowerStateForTest(DisplayPowerState power_state);
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_DISPLAY_DISPLAY_PREFERENCES_H_