Replaced BackgroundAnimator with ShelfBackgroundAnimator.

ash/shelf/shelf.h

Index: ash/shelf/shelf.h
diff --git a/ash/shelf/shelf.h b/ash/shelf/shelf.h
index 4d85bb0fd9a53505a8b36b2a5a0862abdf1e6455..584543956e68c320cac9760035f5d0b19b9f7d92 100644
--- a/ash/shelf/shelf.h
+++ b/ash/shelf/shelf.h
@@ -37,6 +37,7 @@ class View;
 namespace ash {
 class AppListButton;
 class FocusCycler;
+class ShelfBackgroundAnimator;
 class ShelfDelegate;
 class ShelfIconObserver;
 class ShelfModel;
@@ -55,8 +56,9 @@ class ASH_EXPORT Shelf {
 
   Shelf(ShelfModel* model,
         WmShelf* wm_shelf,
-        ShelfWidget* widget);
-  virtual ~Shelf();
+        ShelfWidget* widget,
+        ShelfBackgroundAnimator* background_animator);
+  ~Shelf();
 
   // Return the shelf for the primary display. NULL if no user is logged in yet.
   // Useful for tests. For production code use ForWindow() because the user may