ash: Convert ShelfDelegate to use WmShelf* instead of Shelf*

ash/test/test_shelf_delegate.h

Index: ash/test/test_shelf_delegate.h
diff --git a/ash/test/test_shelf_delegate.h b/ash/test/test_shelf_delegate.h
index 0e51e96a1170af98a7984e051de8f2c9a350cbcc..7a5fc127a747668c1f2901d250942e677847c9b7 100644
--- a/ash/test/test_shelf_delegate.h
+++ b/ash/test/test_shelf_delegate.h
@@ -50,12 +50,12 @@ class TestShelfDelegate : public ShelfDelegate, public aura::WindowObserver {
   void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
 
   // ShelfDelegate implementation.
-  void OnShelfCreated(Shelf* shelf) override;
-  void OnShelfDestroyed(Shelf* shelf) override;
-  void OnShelfAlignmentChanged(Shelf* shelf) override;
-  void OnShelfAutoHideBehaviorChanged(Shelf* shelf) override;
-  void OnShelfAutoHideStateChanged(Shelf* shelf) override;
-  void OnShelfVisibilityStateChanged(Shelf* shelf) override;
+  void OnShelfCreated(WmShelf* shelf) override;
+  void OnShelfDestroyed(WmShelf* shelf) override;
+  void OnShelfAlignmentChanged(WmShelf* shelf) override;
+  void OnShelfAutoHideBehaviorChanged(WmShelf* shelf) override;
+  void OnShelfAutoHideStateChanged(WmShelf* shelf) override;
+  void OnShelfVisibilityStateChanged(WmShelf* shelf) override;
   ShelfID GetShelfIDForAppID(const std::string& app_id) override;
   bool HasShelfIDToAppIDMapping(ShelfID id) const override;
   const std::string& GetAppIDForShelfID(ShelfID id) override;