DevTools: move JS sampling Timeline out of experimental

Source/devtools/front_end/timeline/TracingTimelineModel.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
  * @param {!WebInspector.TracingManager} tracingManager
  * @param {!WebInspector.TracingModel} tracingModel
  * @param {!WebInspector.TimelineModel.Filter} recordFilter
  * @extends {WebInspector.TimelineModel}
@@ skipping 104 matching lines @@
     this.name = name;
     /** @type {!Array.<!WebInspector.TracingModel.Event>} */
     this.events = [];
     /** @type {!Array.<!Array.<!WebInspector.TracingModel.Event>>} */
     this.asyncEvents = [];
 }
 
 WebInspector.TracingTimelineModel.prototype = {
     /**
      * @param {boolean} captureCauses
+     * @param {boolean} enableJSSampling
      * @param {boolean} captureMemory
      * @param {boolean} capturePictures
      */
-    startRecording: function(captureCauses, captureMemory, capturePictures)
+    startRecording: function(captureCauses, enableJSSampling, captureMemory, capturePictures)
     {
         function disabledByDefault(category)
         {
             return "disabled-by-default-" + category;
         }
         var categoriesArray = [
             "-*",
             disabledByDefault("devtools.timeline"),
             disabledByDefault("devtools.timeline.frame"),
             WebInspector.TracingModel.ConsoleEventCategory
         ];
-        if (captureCauses) {
+        if (captureCauses || enableJSSampling)
             categoriesArray.push(disabledByDefault("devtools.timeline.stack"));
-            if (Runtime.experiments.isEnabled("timelineJSCPUProfile")) {
-                this._jsProfilerStarted = true;
-                this._currentTarget = WebInspector.context.flavor(WebInspector.Target);
-                this._configureCpuProfilerSamplingInterval();
-                this._currentTarget.profilerAgent().start();
-            }
+        if (enableJSSampling) {
+            this._jsProfilerStarted = true;
+            this._currentTarget = WebInspector.context.flavor(WebInspector.Target);
+            this._configureCpuProfilerSamplingInterval();
+            this._currentTarget.profilerAgent().start();
         }
+
         if (capturePictures) {
             categoriesArray = categoriesArray.concat([
                 disabledByDefault("devtools.timeline.layers"),
                 disabledByDefault("devtools.timeline.picture"),
                 disabledByDefault("blink.graphics_context_annotations")]);
         }
         var categories = categoriesArray.join(",");
         this._startRecordingWithCategories(categories);
     },
 
@@ skipping 937 matching lines @@
      * @param {!WebInspector.ChunkedReader} reader
      */
     onChunkTransferred: function(reader) { },
 
     /**
      * @param {!WebInspector.ChunkedReader} reader
      * @param {!Event} event
      */
     onError: function(reader, event) { },
 }