DevTools: Show GPU utilization bar on timeline

Source/devtools/front_end/TracingAgent.js

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 22 matching lines @@
  */
 WebInspector.TracingAgent = function()
 {
     this._active = false;
     InspectorBackend.registerTracingDispatcher(new WebInspector.TracingDispatcher(this));
 }
 
 WebInspector.TracingAgent.prototype = {
     /**
      * @param {string} categoryPatterns
+     * @param {string} options
      * @param {function(?string)=} callback
      */
-    start: function(categoryPatterns, callback)
+    start: function(categoryPatterns, options, callback)
     {
-        TracingAgent.start(categoryPatterns, callback);
+        TracingAgent.start(categoryPatterns, options, callback);
         this._active = true;
         this._events = [];
     },
 
     /**
      * @param {function()} callback
      */
     stop: function(callback)
     {
         if (!this._active) {
             callback();
             return;
         }
         this._pendingStopCallback = callback;
         TracingAgent.end();
     },
 
+    /**
+     * @return {!Array.<{cat: string, args: Object, ph: string, ts: number}>}
+     */
     events: function()
     {
         return this._events;
     },
 
     _eventsCollected: function(events)
     {
         Array.prototype.push.apply(this._events, events);
     },
 
@@ skipping 21 matching lines @@
     dataCollected: function(data)
     {
         this._tracingAgent._eventsCollected(data);
     },
 
     tracingComplete: function()
     {
         this._tracingAgent._tracingComplete();
     }
 }
+
+/**
+ * @type {WebInspector.TracingAgent}
+ */
+WebInspector.tracingAgent;