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

ash/common/shelf/shelf_item_delegate.h

Index: ash/common/shelf/shelf_item_delegate.h
diff --git a/ash/common/shelf/shelf_item_delegate.h b/ash/common/shelf/shelf_item_delegate.h
index 8cd6c1172b2ecfe13882edfc9280de7366f6ddc9..ab13a83fe1c7093a00a949a230d89c54b5d1642d 100644
--- a/ash/common/shelf/shelf_item_delegate.h
+++ b/ash/common/shelf/shelf_item_delegate.h
@@ -63,9 +63,6 @@ class ASH_EXPORT ShelfItemDelegate {
   // |event_flags| specifies the flags of the event which triggered this menu.
   virtual ShelfMenuModel* CreateApplicationMenu(int event_flags) = 0;
 
-  // Whether the launcher item is draggable.
-  virtual bool IsDraggable() = 0;
-
   // Closes all windows associated with this item.
   virtual void Close() = 0;
 };