DevTools: Allow disabling timeline live update as an experiment.

Source/devtools/front_end/TimelinePanel.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel 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.
@@ skipping 301 matching lines @@
         panelStatusBarElement.appendChild(this.clearButton.element);
 
         this._filterBar = this._createFilterBar();
         panelStatusBarElement.appendChild(this._filterBar.filterButton().element);
 
         this.garbageCollectButton = new WebInspector.StatusBarButton(WebInspector.UIString("Collect Garbage"), "garbage-collect-status-bar-item");
         this.garbageCollectButton.addEventListener("click", this._garbageCollectButtonClicked, this);
         this._statusBarButtons.push(this.garbageCollectButton);
         panelStatusBarElement.appendChild(this.garbageCollectButton.element);
 
-        panelStatusBarElement.appendChild(WebInspector.SettingsUI.createSettingCheckbox(WebInspector.UIString("Capture stacks"), WebInspector.settings.timelineCaptureStacks, true, undefined,
-                                               WebInspector.UIString("Capture JavaScript stack on every timeline event")));
+        if (WebInspector.experimentsSettings.timelineNoLiveUpdate.isEnabled()) {
+            panelStatusBarElement.appendChild(WebInspector.SettingsUI.createSettingCheckbox(WebInspector.UIString("Live update"),
+                                              WebInspector.settings.timelineLiveUpdate, true, undefined,
+                                              WebInspector.UIString("Show timeline records while recording")));
+        }
+
+        panelStatusBarElement.appendChild(WebInspector.SettingsUI.createSettingCheckbox(WebInspector.UIString("Capture stacks"),
+                                          WebInspector.settings.timelineCaptureStacks, true, undefined,
+                                          WebInspector.UIString("Capture JavaScript stack on every timeline event")));
 
         this._miscStatusBarItems = panelStatusBarElement.createChild("div", "status-bar-item");
 
         this._filtersContainer = this.element.createChild("div", "timeline-filters-header hidden");
         this._filtersContainer.appendChild(this._filterBar.filtersElement());
         this._filterBar.addEventListener(WebInspector.FilterBar.Events.FiltersToggled, this._onFiltersToggled, this);
     },
 
     /**
      * @return {!WebInspector.FilterBar}
@@ skipping 768 matching lines @@
      * @param {!WebInspector.TimelineModel.Record} record
      * @return {boolean}
      */
     accept: function(record)
     {
         return !this._hiddenRecords[record.type];
     },
 
     __proto__: WebInspector.TimelineModel.Filter.prototype
 }