Port of github.com/polymer/polymer.

samples/third_party/todomvc/web/editable_label.html

 <!--
 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.
 -->
-<polymer-element name="editable-label" attributes="value">
+<polymer-element name="editable-label">
   <template>
     <template if="{{!editing}}">
-      <label class='edit-label' on-double-click="edit">{{value}}</label>
+      <label class='edit-label' on-doubleclick="edit">{{value}}</label>
     </template>
     <template if="{{editing}}">
       <form on-submit="update">
         <input id="edit" class="edit editing"
-               on-blur="update" on-key-up="maybeCancel">
+               on-blur="update" on-keyup="maybeCancel">
       </form>
     </template>
   </template>
   <script type="application/dart" src="editable_label.dart"></script>
 </polymer-element>