DevTools: added support for image url & node in tracing-based timeline

Source/devtools/front_end/timeline/TracingModel.js

 /*
  * Copyright 2014 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.
  */
 
 /**
  * @constructor
  * @extends {WebInspector.TargetAwareObject}
  */
@@ skipping 278 matching lines @@
     this.thread = thread;
 
     /** @type {?string} */
     this.warning = null;
     /** @type {?WebInspector.TracingModel.Event} */
     this.initiator = null;
     /** @type {?Array.<!ConsoleAgent.CallFrame>} */
     this.stackTrace = null;
     /** @type {?Element} */
     this.previewElement = null;
+    /** @type {?string} */
+    this.imageURL = null;
+    /** @type {number} */
+    this.backendNodeId = 0;
+
     /** @type {number} */
     this.selfTime = 0;
 }
 
 WebInspector.TracingModel.Event.prototype = {
     /**
      * @param {number} duration
      */
     _setDuration: function(duration)
     {
@@ skipping 238 matching lines @@
     dataCollected: function(data)
     {
         this._tracingModel._eventsCollected(data);
     },
 
     tracingComplete: function()
     {
         this._tracingModel._tracingComplete();
     }
 }