DevTools: Allow disabling timeline live update as an experiment.

Source/devtools/front_end/TimelineManager.js

 /*
  * Copyright (C) 2011 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 39 matching lines @@
     /**
      * @return {boolean}
      */
     isStarted: function()
     {
         return this._dispatcher.isStarted();
     },
 
     /**
      * @param {number=} maxCallStackDepth
+     * @param {boolean=} bufferEvents
      * @param {boolean=} includeCounters
      * @param {boolean=} includeGPUEvents
      * @param {function(?Protocol.Error)=} callback
      */
-    start: function(maxCallStackDepth, includeCounters, includeGPUEvents, callback)
+    start: function(maxCallStackDepth, bufferEvents, includeCounters, includeGPUEvents, callback)
     {
         this._enablementCount++;
         if (this._enablementCount === 1)
-            TimelineAgent.start(maxCallStackDepth, /* bufferEvents */false, includeCounters, includeGPUEvents, callback);
+            TimelineAgent.start(maxCallStackDepth, bufferEvents, includeCounters, includeGPUEvents, callback);
         else if (callback)
             callback(null);
     },
 
     /**
      * @param {function(?Protocol.Error)=} callback
      */
     stop: function(callback)
     {
         this._enablementCount--;
@@ skipping 57 matching lines @@
     {
         this._started = false;
         this._manager.dispatchEventToListeners(WebInspector.TimelineManager.EventTypes.TimelineStopped, consoleTimeline);
     }
 }
 
 /**
  * @type {!WebInspector.TimelineManager}
  */
 WebInspector.timelineManager;