Animating docked background in sync with shelf

ash/system/tray/tray_background_view.h

Index: ash/system/tray/tray_background_view.h
diff --git a/ash/system/tray/tray_background_view.h b/ash/system/tray/tray_background_view.h
index 0f6e2f7858087b628666bd8798120e876f283203..5adaf4ec0c79fab0f1da4060adf2370c2031bcaa 100644
--- a/ash/system/tray/tray_background_view.h
+++ b/ash/system/tray/tray_background_view.h
@@ -108,9 +108,8 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
 
   // Sets whether the tray paints a background. Default is true, but is set to
   // false if a window overlaps the shelf.
-  void SetPaintsBackground(
-      bool value,
-      internal::BackgroundAnimator::ChangeType change_type);
+  void SetPaintsBackground(bool value,
+                           BackgroundAnimatorChangeType change_type);
 
   // Initializes animations for the bubble.
   void InitializeBubbleAnimations(views::Widget* bubble_widget);