Removed polymer & mirror from Observatory

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;
-
-  group('instantiation', () {
-    test('default', () {
-      final e = new NavTopMenuElement();
-      expect(e, isNotNull, reason: 'element correctly created');
-    });
-    test('not last', () {
-      final e = new NavTopMenuElement(last: false);
-      expect(e, isNotNull, reason: 'element correctly created');
-      expect(e.last, isFalse, reason: 'element correctly created');
-    });
-    test('last', () {
-      final e = new NavTopMenuElement(last: true);
-      expect(e, isNotNull, reason: 'element correctly created');
-      expect(e.last, isTrue, reason: 'element correctly created');
-    });
-  });
-  group('elements', () {
-    test('created', () async {
-      final e = new NavTopMenuElement();
-      document.body.append(e);
-      await e.onRendered.first;
-      expect(e.shadowRoot.children.length, isNonZero, reason: 'has elements');
-      expect(e.shadowRoot.querySelector('content'), isNotNull,
-                                                 reason: 'has content elements');
-      e.remove();
-      await e.onRendered.first;
-      expect(e.shadowRoot.children.length, isZero, reason: 'is empty');
-    });
-    test('react to last change', () async {
-      final e = new NavTopMenuElement(last: false);
-      document.body.append(e);
-      await e.onRendered.first;
-      expect((e.shadowRoot.querySelector(tag) as NavMenuElement).last, isFalse);
-      e.last = true;
-      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;
-    });
-  });
-}