mash: Convert all of //ash/system to use WmShelf

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 ac63988e3dfb38e4ab0bf009d27e88180282f313..d1011d06a5d8488a0bf54459a4757d14f61693da 100644
--- a/ash/common/shelf/wm_shelf.h
+++ b/ash/common/shelf/wm_shelf.h
@@ -25,6 +25,11 @@ class WmWindow;
 // Used for accessing global state.
 class ASH_EXPORT WmShelf {
  public:
+  // Returns the shelf for the primary display. Useful in tests that only use
+  // a single display. In production code use WmRootWindowController::GetShelf()
+  // with the appropriate display's root window controller.
+  static WmShelf* ForPrimaryDisplay();

[msw, 2016/06/25 00:18:29]

q: would you like to make this ForTesting?
(based on your comment and wondering about non-test uses...)

[James Cook, 2016/06/25 01:20:58]

As discussed offline, eliminated this in favor of AshTestBase::GetPrimaryShelf()
in tests and explicit lookups in non-test code.

+
   // Returns the window showing the shelf.
   virtual WmWindow* GetWindow() = 0;
 
@@ -71,6 +76,9 @@ class ASH_EXPORT WmShelf {
   virtual void AddObserver(WmShelfObserver* observer) = 0;
   virtual void RemoveObserver(WmShelfObserver* observer) = 0;
 
+  // Simulates a virtual keyboard bounds update.
+  virtual void SetKeyboardBoundsForTesting(const gfx::Rect& bounds) = 0;
+
  protected:
   virtual ~WmShelf() {}
 };