Added TodoMVC startup benchmarks.

samples/third_party/todomvc_performance/js_todomvc/components/polymer-selection/polymer-selection.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.
 -->
 <!--
 /**
  * @module Polymer Elements
  */
 -->
 <!--
 /**
  * The polymer-selection element is used to manage selection state. It has no
  * visual appearance and is typically used in conjuneciton with another element.
  * For example, <a href="polymer-selector.html">polymer-selector</a>
  * use a polymer-selection to manage selection.
  *
- * To mark an item as selected, call the select(item) method on
+ * To mark an item as selected, call the select(item) method on 
  * polymer-selection. Notice that the item itself is an argument to this method.
  * The polymer-selection element manages selection state for any given set of
  * items. When an item is selected, the `polymer-select` event is fired.
  * The attribute "multi" indicates if multiple items can be selected at once.
- *
+ * 
  * Example:
  *
  *     <polymer-element name="selection-example">
  *        <template>
  *          <style>
  *            ::-webkit-distributed(> .selected) {
  *              font-weight: bold;
  *              font-style: italic;
  *            }
  *          </style>
@@ skipping 19 matching lines @@
  *       <li>Green</li>
  *       <li>Blue</li>
  *     </selection-example>
  *
  * @class polymer-selection
  */
  /**
  * Fired when an item's selection state is changed. This event is fired both
  * when an item is selected or deselected. The `isSelected` detail property
  * contains the selection state.
- *
+ * 
  * @event polymer-select
  * @param {Object} detail
  *   @param {boolean} detail.isSelected true for selection and false for deselection
  *   @param {Object} detail.item the item element
  */
 -->
+<link rel="import" href="../polymer/polymer.html">
+
 <polymer-element name="polymer-selection" attributes="multi">
   <template>
     <style>
       :host {
         display: none !important;
       }
     </style>
   </template>
   <script>
     Polymer('polymer-selection', {
       /**
        * If true, multiple selections are allowed.
        *
        * @attribute multi
        * @type boolean
        * @default false
        */
       multi: false,
       ready: function() {
         this.clear();
       },
       clear: function() {
         this.selection = [];
       },
       /**
        * Retrieves the selected item(s).
        * @method getSelection
        * @returns Returns the selected item(s). If the multi property is true,
-       * getSelection will return an array, otherwise it will return
+       * getSelection will return an array, otherwise it will return 
        * the selected item or undefined if there is no selection.
       */
       getSelection: function() {
         return this.multi ? this.selection : this.selection[0];
       },
       /**
        * Indicates if a given item is selected.
        * @method isSelected
        * @param {any} item The item whose selection state should be checked.
        * @returns Returns true if `item` is selected.
@@ skipping 33 matching lines @@
        * Toggles the selection state for `item`.
        * @method toggle
        * @param {any} item: The item to toggle.
       */
       toggle: function(item) {
         this.setItemSelected(item, !this.isSelected(item));
       }
     });
   </script>
 </polymer-element>