mash: Remove shelf app menu item objects.

ash/common/test/test_shelf_item_delegate.cc

Index: ash/common/test/test_shelf_item_delegate.cc
diff --git a/ash/common/test/test_shelf_item_delegate.cc b/ash/common/test/test_shelf_item_delegate.cc
index 2d0faebe6600bf646577dd90691d5e40229dc7dc..e97d865879c8e08a5adf313fc69809b1963276d8 100644
--- a/ash/common/test/test_shelf_item_delegate.cc
+++ b/ash/common/test/test_shelf_item_delegate.cc
@@ -34,6 +34,12 @@ ShelfAppMenuItemList TestShelfItemDelegate::GetAppMenuItems(int event_flags) {
   return ShelfAppMenuItemList();
 }
 
+void TestShelfItemDelegate::ExecuteCommand(uint32_t command_id,
+                                           int32_t event_flags) {
+  // This delegate does not support showing an application menu.
+  NOTIMPLEMENTED();
+}
+
 void TestShelfItemDelegate::Close() {}
 
 }  // namespace test