Fix closure compile after Polymer update

third_party/polymer/v1_0/components-chromium/polymer-externs/polymer.externs.js

 /**
  * @fileoverview Closure compiler externs for the Polymer library.
  *
  * @externs
  * @license
  * Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
  * This code may only be used under the BSD style license found at
  * http://polymer.github.io/LICENSE.txt. The complete set of authors may be
  * found at http://polymer.github.io/AUTHORS.txt. The complete set of
  * contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt. Code
@@ skipping 446 matching lines @@
  *     into the element's `customStyle` property. This argument provides a
  *     shortcut for setting `customStyle` and then calling `updateStyles`.
  */
 PolymerElement.prototype.updateStyles = function(properties) {};
 
 /**
  * @type {!Object<string, string|undefined>}
  */
 PolymerElement.prototype.customStyle;
 
+/** @type {Node|undefined} */
+PolymerElement.prototype.shadyRoot;
+
 /**
  * Logs a message to the console.
  *
  * @param {!Array} var_args
  * @protected
  */
 PolymerElement.prototype._log = function(var_args) {};
 
 /**
  * Logs a message to the console with a 'warn' level.
@@ skipping 435 matching lines @@
  * method does not size the element, and it's usually necessary to set
  * the element's height and width so that the background image is visible.
  *
  * @param {Element} element The element to which the icon is applied.
  * @param {string} icon The name of the icon to apply.
  * @param {string=} theme (optional) The name or index of the icon to apply.
  * @param {number=} scale (optional, defaults to 1) Icon scaling factor.
  */
 Polymer.Iconset.prototype.applyIcon = function(
       element, icon, theme, scale) {};