Add initial implementation of date-time-settings MD settings page.

ui/webui/resources/cr_elements/cr_dropdown_menu/cr_dropdown_menu.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * `cr-dropdown-menu` is a Chrome-specific wrapper around paper-dropdown-menu.
  * It includes a paper-dropdown so its content should just be a core-menu and
  * items.
  *
@@ skipping 31 matching lines @@
      */
     label: '<Dropdown Menu Label>',
 
     /**
      * True if the menu is disabled.
      *
      * @attribute disabled
      * @type boolean
      * @default false
      */
-    disabled: {value: false, reflected: true},
+    disabled: {value: false, reflect: true},
   },
 
   /** @override */
   domReady: function() {
     assert(
         this.querySelector('.menu'),
         'cr-dropdown-menu must have a menu child with class="menu".');
   },
 });