Allow storing display preferences per device.

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_
+
+class PrefService;
+namespace gfx {
+class Display;
+}
+
+namespace chromeos {
+
+// Registers the prefs associated with display settings.
+void RegisterDisplayPrefs(PrefService* pref_service);
+
+// Sets or updates the display layout data to the specified |display| and
+// |pref_service|.
+void SetDisplayLayoutPref(PrefService* pref_service,
+                          const gfx::Display& display,
+                          int layout,
+                          int offset);
+
+// Checks the current display settings values and notifies them to the system.
+void NotifyDisplayPrefChanged(PrefService* pref_service);
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_DISPLAY_DISPLAY_PREFERENCES_H_