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

ash/shelf/shelf_layout_manager.h

Index: ash/shelf/shelf_layout_manager.h
diff --git a/ash/shelf/shelf_layout_manager.h b/ash/shelf/shelf_layout_manager.h
index 1e7eea62b2db6c35820d942070b0d136ba49c8b9..127fff861adcb0c1762a018283b6176f5e2bffc4 100644
--- a/ash/shelf/shelf_layout_manager.h
+++ b/ash/shelf/shelf_layout_manager.h
@@ -162,6 +162,9 @@ class ASH_EXPORT ShelfLayoutManager
       aura::Window* gained_active,
       aura::Window* lost_active) override;
 
+  // Overridden from keyboard::KeyboardControllerObserver:
+  void OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) override;
+
   // Overridden from ash::LockStateObserver:
   void OnLockStateEvent(LockStateObserver::EventType event) override;
 
@@ -301,9 +304,6 @@ class ASH_EXPORT ShelfLayoutManager
 
   int GetWorkAreaInsets(const State& state, int size) const;
 
-  // Overridden from keyboard::KeyboardControllerObserver:
-  void OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) override;
-
   // Overridden from DockedWindowLayoutManagerObserver:
   void OnDockBoundsChanging(
       const gfx::Rect& dock_bounds,