DevTools: Route timeline context menu save/load actions through module extensions.

third_party/WebKit/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 427 matching lines @@
         this._fileSelectorElement = WebInspector.createFileSelectorElement(this._loadFromFile.bind(this));
         this.element.appendChild(this._fileSelectorElement);
     },
 
     /**
      * @param {!Event} event
      */
     _contextMenu: function(event)
     {
         var contextMenu = new WebInspector.ContextMenu(event);
-        var disabled = this._state !== WebInspector.TimelinePanel.State.Idle;
-        contextMenu.appendItem(WebInspector.UIString.capitalize("Save Timeline ^data\u2026"), this._saveToFile.bind(this), disabled);
-        contextMenu.appendItem(WebInspector.UIString.capitalize("Load Timeline ^data\u2026"), this._selectFileToLoad.bind(this), disabled);
+        contextMenu.appendItemsAtLocation("timelineMenu");
         contextMenu.show();
     },
 
     /**
      * @return {boolean}
      */
     _saveToFile: function()
     {
         if (this._state !== WebInspector.TimelinePanel.State.Idle)
             return true;
+        if (this._model.isEmpty())
+            return true;
 
         var now = new Date();
         var fileName = "TimelineRawData-" + now.toISO8601Compact() + ".json";
         var stream = new WebInspector.FileOutputStream();
 
         /**
          * @param {boolean} accepted
          * @this {WebInspector.TimelinePanel}
          */
         function callback(accepted)
@@ skipping 1566 matching lines @@
      * @override
      * @param {!WebInspector.Target} target
      */
     targetRemoved: function(target)
     {
         this._targets.remove(target, true);
     },
 
     __proto__: WebInspector.Object.prototype
 }