[polymer] interop with polymer-element and polymer.js

samples/third_party/todomvc/web/lib-elements/polymer_selector.html

-<!--
-Copyright 2013 The Polymer Authors. All rights reserved.
-Use of this source code is governed by a BSD-style
-license that can be found in the LICENSE file.
--->
-<!--
-/**
- * polymer-selector is used to display a list of elements that can be selected.
- * The attribute "selected" indicates which element is being selected.
- * Tapping on the element to change selection would fire "polymer-activate"
- * event.
- *
- * Example:
- *
- *     <polymer-selector selected="0" on-polymer-activate="{{activateAction}}">
- *       <div>Item 1</div>
- *       <div>Item 2</div>
- *       <div>Item 3</div>
- *     </polymer-selector>
- *
- * polymer-selector is not styled.  So one needs to use "selected" CSS class
- * to style the selected element.
- *
- *     <style>
- *       .item.polymer-selected {
- *         background: #eee;
- *       }
- *     </style>
- *     ...
- *     <polymer-selector>
- *       <div class="item">Item 1</div>
- *       <div class="item">Item 2</div>
- *       <div class="item">Item 3</div>
- *     </polymer-selector>
- */
--->
-<link rel="import" href="polymer_selection.html">
-
-<polymer-element name="polymer-selector" on-tap="{{activateHandler}}"
-    touch-action="none">
-  <template>
-    <polymer-selection id="selection" multi="{{multi}}"
-        on-polymer-select="{{selectionSelect}}"></polymer-selection>
-    <content id="items" select="*"></content>
-  </template>
-  <script type="application/dart" src="polymer_selector.dart"></script>
-</polymer-element>