Unify and change logout/sleep/lock shortcuts

ash/accelerators/accelerator_controller.h

Index: ash/accelerators/accelerator_controller.h
diff --git a/ash/accelerators/accelerator_controller.h b/ash/accelerators/accelerator_controller.h
index 53ed723d1e0ac991c0e9eb459979b107e6212e38..e2e9af0b55717491bdfd8412a84e371d719c3ead 100644
--- a/ash/accelerators/accelerator_controller.h
+++ b/ash/accelerators/accelerator_controller.h
@@ -23,6 +23,7 @@ namespace ash {
 
 struct AcceleratorData;
 class BrightnessControlDelegate;
+class ExitWarningHandler;
 class ImeControlDelegate;
 class KeyboardBrightnessControlDelegate;
 class ScreenshotDelegate;
@@ -134,6 +135,7 @@ class ASH_EXPORT AcceleratorController : public ui::AcceleratorTarget {
   // TODO(derat): BrightnessControlDelegate is also used by the system tray;
   // move it outside of this class.
   scoped_ptr<BrightnessControlDelegate> brightness_control_delegate_;
+  scoped_ptr<ExitWarningHandler> exit_warning_handler_;
   scoped_ptr<ImeControlDelegate> ime_control_delegate_;
   scoped_ptr<KeyboardBrightnessControlDelegate>
       keyboard_brightness_control_delegate_;