Remove ShelfItemDelegate::IsDraggable; check for app list button.

ash/common/test/test_shelf_item_delegate.h

Index: ash/common/test/test_shelf_item_delegate.h
diff --git a/ash/common/test/test_shelf_item_delegate.h b/ash/common/test/test_shelf_item_delegate.h
index 8eb756486bec10622c87f354ce4bf4d586a07a04..dac15e1995b62b5587efd52d9dc92daaea0d29b4 100644
--- a/ash/common/test/test_shelf_item_delegate.h
+++ b/ash/common/test/test_shelf_item_delegate.h
@@ -21,22 +21,17 @@ class TestShelfItemDelegate : public ShelfItemDelegate {
   explicit TestShelfItemDelegate(WmWindow* window);
   ~TestShelfItemDelegate() override;
 
-  void set_is_draggable(bool is_draggable) { is_draggable_ = is_draggable; }
-
   // ShelfItemDelegate:
   ShelfItemDelegate::PerformedAction ItemSelected(
       const ui::Event& event) override;
   base::string16 GetTitle() override;
   ShelfMenuModel* CreateApplicationMenu(int event_flags) override;
-  bool IsDraggable() override;
   bool CanPin() const override;
   void Close() override;
 
  private:
   WmWindow* window_;
 
-  bool is_draggable_;
-
   DISALLOW_COPY_AND_ASSIGN(TestShelfItemDelegate);
 };