Update Polymer components.

third_party/polymer/components/paper-menu/paper-menu.html

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 This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
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 <link rel="import" href="../polymer/polymer.html">
-<link rel="import" href="../iron-flex-layout/iron-flex-layout.html">
 <link rel="import" href="../iron-menu-behavior/iron-menu-behavior.html">
 <link rel="import" href="../paper-styles/default-theme.html">
-<link rel="import" href="../paper-styles/color.html">
 <link rel="import" href="paper-menu-shared-styles.html">
 
 <!--
 Material design: [Menus](https://www.google.com/design/spec/components/menus.html)
 
 `<paper-menu>` implements an accessible menu control with Material Design styling. The focused item
 is highlighted, and the selected item has bolded text.
 
     <paper-menu>
       <paper-item>Item 1</paper-item>
@@ skipping 67 matching lines @@
       Polymer({
         is: 'paper-menu',
 
         behaviors: [
           Polymer.IronMenuBehavior
         ]
       });
     })();
   </script>
 </dom-module>