Revert of Replaced BackgroundAnimator with ShelfBackgroundAnimator.

ash/common/shelf/app_list_button.h

Index: ash/common/shelf/app_list_button.h
diff --git a/ash/common/shelf/app_list_button.h b/ash/common/shelf/app_list_button.h
index af0fdbd9d4192fd552694607b66fa31ae5b5ab5f..0fabb4a62db82825639115978892a029acdb596a 100644
--- a/ash/common/shelf/app_list_button.h
+++ b/ash/common/shelf/app_list_button.h
@@ -26,9 +26,6 @@
   void OnAppListDismissed();
 
   bool draw_background_as_active() { return draw_background_as_active_; }
-
-  // Sets alpha value of the background and schedules a paint.
-  void SetBackgroundAlpha(int alpha);
 
  protected:
   // views::ImageButton overrides:
@@ -64,9 +61,6 @@
   // the application list.
   bool draw_background_as_active_;
 
-  // Alpha value used to paint the background.
-  int background_alpha_;
-
   InkDropButtonListener* listener_;
   ShelfView* shelf_view_;
   WmShelf* wm_shelf_;