Animating docked background in sync with shelf

ash/shelf/shelf_widget.h

Index: ash/shelf/shelf_widget.h
diff --git a/ash/shelf/shelf_widget.h b/ash/shelf/shelf_widget.h
index c7adb742555845ad3da53dc620b615ac45a6d6d5..83d4a8d70135a1bc30c8c8ecd7f2eb9d09ed5f8c 100644
--- a/ash/shelf/shelf_widget.h
+++ b/ash/shelf/shelf_widget.h
@@ -43,12 +43,11 @@ class ASH_EXPORT ShelfWidget : public views::Widget,
   ShelfAlignment GetAlignment() const;
 
   // Sets the shelf's background type.
-  void SetPaintsBackground(
-      ShelfBackgroundType background_type,
-      internal::BackgroundAnimator::ChangeType change_type);
+  void SetPaintsBackground(ShelfBackgroundType background_type,
+                           BackgroundAnimatorChangeType change_type);
   ShelfBackgroundType GetBackgroundType() const;
 
-  // Causes shelf items to be slightly dimmed (eg when a window is maximized).
+  // Causes shelf items to be slightly dimmed (e.g. when a window is maximized).
   void SetDimsShelf(bool dimming);
   bool GetDimsShelf() const;