Converted Observatory cpu-profile element

runtime/observatory/tests/observatory_ui/nav/top-menu/element_test.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
+
 import 'dart:html';
 import 'package:unittest/unittest.dart';
 import 'package:observatory/src/elements/nav/menu.dart';
 import 'package:observatory/src/elements/nav/top_menu.dart';
 
 main() {
   NavTopMenuElement.tag.ensureRegistration();
 
   final tag = NavMenuElement.tag.name;
 
@@ skipping 34 matching lines @@
       await e.onRendered.first;
       expect((e.shadowRoot.querySelector(tag) as NavMenuElement).last, isTrue);
       e.last = false;
       await e.onRendered.first;
       expect((e.shadowRoot.querySelector(tag) as NavMenuElement).last, isFalse);
       e.remove();
       await e.onRendered.first;
     });
   });
 }