Compile print_preview, part 2: reduce down to 260 errors

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.
  */
 
 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}

[Dan Beam, 2014/09/23 00:46:34]

this is a confusing statement.  i assume this means that it implements
EventTarget provided by the browser, not itself?

[Vitaly Pavlenko, 2014/09/23 01:05:17]

Yes, all our constructors are visible to Closure compiler only by their
full-qualified names. Sometimes I need to add a constructor to the list of
exported entities just to use it inside JSDoc in the same file where it's
declared. So here it's definitely EventTarget coming from compiler externs.

    */
   function EventTarget() {
   }
 
   EventTarget.prototype = {
 
     /**
      * Adds an event listener to the target.
      * @param {string} type The name of the event.
      * @param {!Function|{handleEvent:Function}} handler The handler for the
@@ skipping 66 matching lines @@
 
       return !prevented && !event.defaultPrevented;
     }
   };
 
   // Export
   return {
     EventTarget: EventTarget
   };
 });