mash: Migrate ShelfButton* to wm common types

ash/common/shelf/wm_shelf.h

Index: ash/common/shelf/wm_shelf.h
diff --git a/ash/common/shelf/wm_shelf.h b/ash/common/shelf/wm_shelf.h
index 763f417ab190e608088f4f4b5c5181255d5d535b..0fbee4bc0b76c8150ee1b5008957e9191bfc0d89 100644
--- a/ash/common/shelf/wm_shelf.h
+++ b/ash/common/shelf/wm_shelf.h
@@ -20,6 +20,7 @@ class MouseEvent;
 namespace ash {
 
 class ShelfLockingManager;
+class ShelfView;
 class WmShelfObserver;
 class WmWindow;
 
@@ -93,6 +94,7 @@ class ASH_EXPORT WmShelf {
   virtual void SetKeyboardBoundsForTesting(const gfx::Rect& bounds) = 0;
 
   virtual ShelfLockingManager* GetShelfLockingManagerForTesting() = 0;
+  virtual ShelfView* GetShelfViewForTesting() = 0;

[James Cook, 2016/07/27 19:43:00]

I did this because I wanted to move the unit test with the code it tests, and I
didn't want to introduce a WmShelfTestApi since (a) WmShelfAura doesn't have
access to ShelfView and (b) I'm not yet sure how unit tests will work after the
mus flip.

[msw, 2016/07/27 20:12:34]

Acknowledged.

 
  protected:
   virtual ~WmShelf() {}