Revert 162140 - ash : Decouple power button controller and session state controller.

ash/shell.h

Index: ash/shell.h
===================================================================
--- ash/shell.h	(revision 162199)
+++ ash/shell.h	(working copy)
@@ -68,7 +68,6 @@
 class NestedDispatcherController;
 class PowerButtonController;
 class ScreenAsh;
-class SessionStateController;
 class ShellDelegate;
 class ShellObserver;
 class SystemTrayDelegate;
@@ -274,9 +273,6 @@
   PowerButtonController* power_button_controller() {
     return power_button_controller_.get();
   }
-  SessionStateController* session_state_controller() {
-    return session_state_controller_.get();
-  }
   UserActivityDetector* user_activity_detector() {
     return user_activity_detector_.get();
   }
@@ -448,7 +444,6 @@
   scoped_ptr<internal::VisibilityController> visibility_controller_;
   scoped_ptr<DesktopBackgroundController> desktop_background_controller_;
   scoped_ptr<PowerButtonController> power_button_controller_;
-  scoped_ptr<SessionStateController> session_state_controller_;
   scoped_ptr<UserActivityDetector> user_activity_detector_;
   scoped_ptr<VideoDetector> video_detector_;
   scoped_ptr<WindowCycleController> window_cycle_controller_;