Cleanup ash shelf accessor functions.

ash/shelf/overflow_bubble_view.h

Index: ash/shelf/overflow_bubble_view.h
diff --git a/ash/shelf/overflow_bubble_view.h b/ash/shelf/overflow_bubble_view.h
index 5feeeed84af51ccdc487d02fb028c82197b53ffb..fd31157147e15e90e4a1a4852c154b4b9c627e3b 100644
--- a/ash/shelf/overflow_bubble_view.h
+++ b/ash/shelf/overflow_bubble_view.h
@@ -11,7 +11,6 @@
 #include "ui/views/bubble/bubble_delegate.h"
 
 namespace ash {
-class ShelfLayoutManager;
 class ShelfView;
 
 namespace test {
@@ -43,8 +42,6 @@ class ASH_EXPORT OverflowBubbleView : public views::BubbleDelegateView {
   void ScrollByXOffset(int x_offset);
   void ScrollByYOffset(int y_offset);
 
-  ShelfLayoutManager* GetShelfLayoutManager() const;
-
   // views::View overrides:
   gfx::Size GetPreferredSize() const override;
   void Layout() override;