DevTools: Allow disabling timeline live update as an experiment.

Source/devtools/front_end/TimelineManager.js

Index: Source/devtools/front_end/TimelineManager.js
diff --git a/Source/devtools/front_end/TimelineManager.js b/Source/devtools/front_end/TimelineManager.js
index 879dc4f77b92105ab37e2c3619366c052f19b086..c8cd89336ad0bb5bcbb09160f4199868a7f268ea 100644
--- a/Source/devtools/front_end/TimelineManager.js
+++ b/Source/devtools/front_end/TimelineManager.js
@@ -57,15 +57,16 @@ WebInspector.TimelineManager.prototype = {
 
     /**
      * @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);
     },