Port of github.com/polymer/polymer.

pkg/polymer/example/component/news/web/news-component.html

 <polymer-element name="x-news" extends="ul">
   <template>
     <style scoped>
       div.breaking {
           color: Red;
           font-size: 20px;
           border: 1px dashed Purple;
       }
       div.other {
           padding: 2px 0 0 0;
@@ skipping 13 matching lines @@
       </ul>
     </div>
   </template>
   <script type="application/dart">
     import 'package:polymer/polymer.dart';
 
     class XNews extends PolymerElement {}
 
     @initMethod
     _init() {
-      registerPolymerElement('x-news', () => new XNews());
+      Polymer.register('x-news', XNews);
     }
   </script>
 </polymer-element>