Delete polymer from the Dart repo

pkg/polymer/example/component/news/test/news_index_test.dart

-// Copyright (c) 2013, 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:polymer/polymer.dart';
-import 'package:unittest/unittest.dart';
-import 'package:unittest/html_config.dart';
-
-/// This test runs the news example and checks the state of the initial page.
-main() {
-  initPolymer();
-  useHtmlConfiguration();
-
-  extractLinks(nodes) => nodes.where((n) => n is Element)
-      .map((n) => n.query('a').href.split('/').last).toList();
-
-  test('initial state', () {
-    final listComp = querySelector('ul');
-    final items = listComp.querySelectorAll('li');
-    expect(items.length, 6);
-    expect(extractLinks(items), ['1', '2', '3', '4', '4', '5']);
-    expect(listComp is Polymer, true, reason: 'x-news should be created');
-
-    final contents = listComp.shadowRoot.querySelectorAll('content');
-    expect(contents.length, 2, reason: 'news has 2 content tags');
-    expect(extractLinks(contents[0].getDistributedNodes()),
-        ['3', '5'], reason: 'breaking stories first');
-    expect(extractLinks(contents[1].getDistributedNodes()),
-        ['1', '2', '4', '4'], reason: 'other stories after breaking stories');
-  });
-}