Remove --ash-disable-overview-mode

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 4b0df83c76a4a2ab087d71d75b56a9012174296c..c67f2da56278d86b76a88f4fd51a6b05fbcd3866 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -370,9 +370,6 @@ class ASH_EXPORT Shell
   VideoDetector* video_detector() {
     return video_detector_.get();
   }
-  WindowCycleController* window_cycle_controller() {
-    return window_cycle_controller_.get();
-  }
   WindowSelectorController* window_selector_controller() {
     return window_selector_controller_.get();
   }
@@ -657,7 +654,6 @@ class ASH_EXPORT Shell
   scoped_ptr<MruWindowTracker> mru_window_tracker_;
   scoped_ptr<UserActivityDetector> user_activity_detector_;
   scoped_ptr<VideoDetector> video_detector_;
-  scoped_ptr<WindowCycleController> window_cycle_controller_;
   scoped_ptr<WindowSelectorController> window_selector_controller_;
   scoped_ptr<internal::FocusCycler> focus_cycler_;
   scoped_ptr<DisplayController> display_controller_;