update

Author: chunhtai

packages/devtools_app/lib/src/screens/accessibility/accessibility_controller.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file or at https://developers.google.com/open-source/licenses/bsd.
 
-import 'dart:async';
-
 import 'package:devtools_app_shared/utils.dart';
 import 'package:flutter/foundation.dart';