DevTools: do not lazy load provided view if it was explicitly added.

third_party/WebKit/Source/devtools/front_end/ui/TabbedPane.js

 /*
  * Copyright (C) 2010 Google 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1359 matching lines @@
             this._appendTab(/** @type {!Runtime.Extension} */(this._extensions.get(id)));
         this._tabbedPane.selectTab(id);
     },
 
     /**
      * @param {!WebInspector.Event} event
      */
     _tabSelected: function(event)
     {
         var tabId = /** @type {string} */ (event.data.tabId);
+        if (!this._extensions.has(tabId))
+            return;
+
         this._viewForId(tabId);
 
         var descriptor = this._extensions.get(tabId).descriptor();
         if (descriptor["persistence"] === "closeable") {
             var tabs = this._closeableTabSetting.get();
             if (!tabs[tabId]) {
                 tabs[tabId] = true;
                 this._closeableTabSetting.set(tabs);
             }
         }
@@ skipping 33 matching lines @@
         function cacheView(object)
         {
             var view = /** @type {!WebInspector.Widget} */ (object);
             if (this._viewCallback && view)
                 this._viewCallback(id, view);
             this._tabbedPane.changeTabView(id, view);
             return view;
         }
     }
 }