Fix about:tracing recording a second trace.

chrome/browser/resources/tracing/timeline.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 Interactive visualizaiton of TimelineModel objects
  * based loosely on gantt charts. Each thread in the TimelineModel is given a
  * set of TimelineTracks, one per subrow in the thread. The Timeline class
  * acts as a controller, creating the individual tracks, while TimelineTracks
  * do actual drawing.
@@ skipping 101 matching lines @@
      */
     dispatchChangeEvent: function() {
       cr.dispatchSimpleEvent(this, 'change');
     },
 
     detach: function() {
       if (this.checkForAttachInterval_) {
         window.clearInterval(this.checkForAttachInterval_);
         this.checkForAttachInterval_ = undefined;
       }
-      this.iframe_.removeListener('resize', this.onResizeBoundToThis_);
+      this.iframe_.removeEventListener('resize', this.onResizeBoundToThis_);
       this.parentEl_.removeChild(this.iframe_);
     },
 
     get scaleX() {
       return this.scaleX_;
     },
     set scaleX(s) {
       var changed = this.scaleX_ != s;
       if (changed) {
         this.scaleX_ = s;
@@ skipping 590 matching lines @@
    * The TimelineModel being viewed by the timeline
    * @type {TimelineModel}
    */
   cr.defineProperty(Timeline, 'model', cr.PropertyKind.JS);
 
   return {
     Timeline: Timeline,
     TimelineViewport: TimelineViewport
   };
 });