Fix some JS style nits.

ui/webui/resources/js/event_tracker.js

 // Copyright (c) 2011 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 EventTracker is a simple class that manages the addition and
  * removal of DOM event listeners. In particular, it keeps track of all
  * listeners that have been added and makes it easy to remove some or all of
  * them without requiring all the information again. This is particularly handy
  * when the listener is a generated function such as a lambda or the result of
@@ skipping 13 matching lines @@
 
 /**
  * Create an EventTracker to track a set of events.
  * EventTracker instances are typically tied 1:1 with other objects or
  * DOM elements whose listeners should be removed when the object is disposed
  * or the corresponding elements are removed from the DOM.
  * @constructor
  */
 function EventTracker() {
   /**
-   * @type {Array.<EventTrackerEntry>}
+   * @type {Array<EventTrackerEntry>}
    * @private
    */
   this.listeners_ = [];
 }
 
 EventTracker.prototype = {
   /**
    * Add an event listener - replacement for EventTarget.addEventListener.
    * @param {!EventTarget} target The DOM target to add a listener to.
    * @param {string} eventType The type of event to subscribe to.
@@ skipping 38 matching lines @@
 
 /**
  * Remove a single event listener given it's tracking entry. It's up to the
  * caller to ensure the entry is removed from listeners_.
  * @param {EventTrackerEntry} h The entry describing the listener to remove.
  * @private
  */
 EventTracker.removeEventListener_ = function(h) {
   h.target.removeEventListener(h.eventType, h.listener, h.capture);
 };