DevTools: Merge main thread strips on timeline overview into a single one.

Source/devtools/front_end/timeline/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 364 matching lines @@
             durationOptions.push(durationOption);
         }
         this._filters._durationFilterUI = new WebInspector.ComboBoxFilterUI(durationOptions);
         this._filters._durationFilterUI.addEventListener(WebInspector.FilterUI.Events.FilterChanged, this._durationFilterChanged, this);
         this._filterBar.addFilter(this._filters._durationFilterUI);
 
         this._filters._categoryFiltersUI = {};
         var categories = WebInspector.TimelineUIUtils.categories();
         for (var categoryName in categories) {
             var category = categories[categoryName];
-            if (category.overviewStripGroupIndex < 0)
+            if (!category.visible)
                 continue;
             var filter = new WebInspector.CheckboxFilterUI(category.name, category.title);
             this._filters._categoryFiltersUI[category.name] = filter;
             filter.addEventListener(WebInspector.FilterUI.Events.FilterChanged, this._categoriesFilterChanged.bind(this, categoryName), this);
             this._filterBar.addFilter(filter);
         }
         return this._filterBar;
     },
 
     _textFilterChanged: function(event)
@@ skipping 1208 matching lines @@
 WebInspector.TimelinePanelFactory.prototype = {
     /**
      * @override
      * @return {!WebInspector.Panel}
      */
     createPanel: function()
     {
         return WebInspector.TimelinePanel.instance();
     }
 }