Practically remove boot.js, adds the initialization from the Dart side of

samples/third_party/todomvc/web/router_options.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.
 
 library todomvc.web.router_options;
 
 import 'dart:html';
 import 'package:polymer/polymer.dart';
 
 /**
  * Given a set of child links to this page, this will add the "selected" CSS
  * class to the link that matches window.location.hash.
  *
  * For example, if the current window.location.hash is "#/completed" and we
  * have a tag like `<a href="#/completed">` it will get the class
  * `class="selected"`, and other links will have that CSS class removed.
  */
 @CustomTag('router-options')
-class RouterOptions extends PolymerElement {
-
-  factory RouterOptions() => new Element.tag('router-options');

[Jennifer Messerly, 2013/10/17 02:04:35]

even though it's unused, should we keep this to show how to make programmatic
creation work?

[Siggi Cherem (dart-lang), 2013/10/17 02:37:40]

Done. Now it becomes:
factory RouterOptions() => new Element.tag('ul', 'router-options');

-
-  RouterOptions.created() : super.created();
+class RouterOptions extends UListElement with Polymer, ObservableMixin {
+  RouterOptions.created() : super.created() {
+    polymerCreated();
+  }
 
   bool get applyAuthorStyles => true;
   var _sub;
 
   void enteredView() {
     super.enteredView();
 
     var anchors = this.queryAll('a');
 
     _updateHash(records) {
@@ skipping 10 matching lines @@
 
     _updateHash(null);
     _sub = windowLocation.changes.listen(_updateHash);
   }
 
   void leftView() {
     _sub.cancel();
     super.leftView();
   }
 }