Fix some JS style nits.

ui/webui/resources/cr_elements/cr_events/cr_events.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-events` provides helpers for handling events in Chrome Polymer elements.
  *
  * Example:
  *
  *    <cr-events id="events"></cr-events>
  *
  * Usage:
  *
  *    this.$.events.forward(this.$.element, ['change']);
  *
  * @element cr-events
  */
 Polymer({
   /**
    * Sets up an element to forward events across the shadow boundary, for events
    * which normally stop at the root node (see http://goo.gl/WGMO9x).
    * @param {!HTMLElement} element The element to forward events from.
-   * @param {!Array.<string>} events The events to forward.
+   * @param {!Array<string>} events The events to forward.
    */
   forward: function(element, events) {
     for (var i = 0; i < events.length; i++)
       element.addEventListener(events[i], this.forwardEvent_);
   },
 
   /**
    * Forwards events that don't automatically cross the shadow boundary
    * if the event should bubble.
    * @param {!Event} e The event to forward.
    * @param {*} detail Data passed when initializing the event.
    * @param {Node=} opt_sender Node that declared the handler.
    * @private
    */
   forwardEvent_: function(e, detail, opt_sender) {
     if (!e.bubbles)
       return;
 
     var node = e.path[e.path.length - 1];
     if (node instanceof ShadowRoot) {
       // Forward the event to the shadow host.
       e.stopPropagation();
       node.host.fire(e.type, detail, node.host, true, e.cancelable);
     }
   },
 });