Revert of All changes to ui/webui/ from bookmarks CL that block other CLs

ui/webui/resources/js/cr/event_target.js

 // Copyright (c) 2010 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 This contains an implementation of the EventTarget interface
  * as defined by DOM Level 2 Events.
  */
 
-/**
- * @typedef {EventListener|function(!Event):(boolean|undefined)}
- */
-var EventListenerType;
-
 cr.define('cr', function() {
 
   /**
    * Creates a new EventTarget. This class implements the DOM level 2
    * EventTarget interface and can be used wherever those are used.
    * @constructor
    * @implements {EventTarget}
    */
   function EventTarget() {
   }
 
   EventTarget.prototype = {
 
     /**
      * Adds an event listener to the target.
      * @param {string} type The name of the event.
-     * @param {EventListenerType} handler The handler for the event. This is
-     *     called when the event is dispatched.
+     * @param {!Function|{handleEvent:Function}} handler The handler for the
+     *     event. This is called when the event is dispatched.
      */
     addEventListener: function(type, handler) {
       if (!this.listeners_)
         this.listeners_ = Object.create(null);
       if (!(type in this.listeners_)) {
         this.listeners_[type] = [handler];
       } else {
         var handlers = this.listeners_[type];
         if (handlers.indexOf(handler) < 0)
           handlers.push(handler);
       }
     },
 
     /**
      * Removes an event listener from the target.
      * @param {string} type The name of the event.
-     * @param {EventListenerType} handler The handler for the event.
+     * @param {!Function|{handleEvent:Function}} handler The handler for the
+     *     event.
      */
     removeEventListener: function(type, handler) {
       if (!this.listeners_)
         return;
       if (type in this.listeners_) {
         var handlers = this.listeners_[type];
         var index = handlers.indexOf(handler);
         if (index >= 0) {
           // Clean up if this was the last listener.
           if (handlers.length == 1)
@@ skipping 37 matching lines @@
 
       return !prevented && !event.defaultPrevented;
     }
   };
 
   // Export
   return {
     EventTarget: EventTarget
   };
 });