DevTools: switch Timeline frontend into buffered mode and remove the corresponding experiment.

Source/devtools/front_end/sdk/TimelineManager.js

Index: Source/devtools/front_end/sdk/TimelineManager.js
diff --git a/Source/devtools/front_end/sdk/TimelineManager.js b/Source/devtools/front_end/sdk/TimelineManager.js
index e984509b6f27211553add795cf0422fc93582860..4c8e00298648f66dba9f6efae9fb47a0e0bea1d2 100644
--- a/Source/devtools/front_end/sdk/TimelineManager.js
+++ b/Source/devtools/front_end/sdk/TimelineManager.js
@@ -60,13 +60,12 @@ WebInspector.TimelineManager.prototype = {
 
     /**
      * @param {number=} maxCallStackDepth
-     * @param {boolean=} bufferEvents
      * @param {string=} liveEvents
      * @param {boolean=} includeCounters
      * @param {boolean=} includeGPUEvents
      * @param {function(?Protocol.Error)=} callback
      */
-    start: function(maxCallStackDepth, bufferEvents, liveEvents, includeCounters, includeGPUEvents, callback)
+    start: function(maxCallStackDepth, liveEvents, includeCounters, includeGPUEvents, callback)
     {
         this._enablementCount++;
         this.target().profilingLock.acquire();
@@ -76,7 +75,7 @@ WebInspector.TimelineManager.prototype = {
             this.target().profilerAgent().start();
         }
         if (this._enablementCount === 1)
-            this.target().timelineAgent().start(maxCallStackDepth, bufferEvents, liveEvents, includeCounters, includeGPUEvents, callback);
+            this.target().timelineAgent().start(maxCallStackDepth, true, liveEvents, includeCounters, includeGPUEvents, callback);
         else if (callback)
             callback(null);
     },
@@ -102,7 +101,6 @@ WebInspector.TimelineManager.prototype = {
         }
         if (!this._enablementCount)
             this.target().timelineAgent().stop(callbackBarrier.createCallback(timelineCallback));
-            TimelineAgent.stop(callbackBarrier.createCallback(timelineCallback));
 
         callbackBarrier.callWhenDone(allDoneCallback.bind(this));