Refactoring display configuration state to allow generic state objects

ui/display/chromeos/native_display_observer.h

 // Copyright 2014 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_DISPLAY_NATIVE_DISPLAY_OBSERVER_H_
-#define CHROMEOS_DISPLAY_NATIVE_DISPLAY_OBSERVER_H_
+#ifndef UI_DISPLAY_CHROMEOS_NATIVE_DISPLAY_OBSERVER_H_
+#define UI_DISPLAY_CHROMEOS_NATIVE_DISPLAY_OBSERVER_H_
 
-namespace chromeos {
+#include "ui/display/display_export.h"
+
+namespace ui {
 
 // Observer class used by NativeDisplayDelegate to announce when the display
 // configuration changes.
-class NativeDisplayObserver {
+class DISPLAY_EXPORT NativeDisplayObserver {
  public:
   virtual ~NativeDisplayObserver() {}
 
   virtual void OnConfigurationChanged() = 0;
 };
 
-}  // namespace chromeos
+}  // namespace ui
 
-#endif  // CHROMEOS_DISPLAY_NATIVE_DISPLAY_OBSERVER_H_
+#endif  // UI_DISPLAY_CHROMEOS_NATIVE_DISPLAY_OBSERVER_H_