DevTools: fix author shadow dom inspection mode, speacial-case ua. Fix crash from the bug.

Source/devtools/front_end/InspectElementModeController.js

 /*
  * Copyright (C) 2013 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:
  *
  * 1. Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *
@@ skipping 51 matching lines @@
 
         /**
          * @param {?Protocol.Error} error
          * @this {WebInspector.InspectElementModeController}
          */
         function callback(error)
         {
             if (!error)
                 this.toggleSearchButton.toggled = enabled;
         }
-        WebInspector.domAgent.setInspectModeEnabled(enabled, WebInspector.settings.showShadowDOM.get(), callback.bind(this));
+        WebInspector.domAgent.setInspectModeEnabled(enabled, WebInspector.settings.showUAShadowDOM.get(), callback.bind(this));
     },
 
     /**
      * @param {!KeyboardEvent} event
      * @return {boolean}
      */
     handleShortcut: function(event)
     {
         if (WebInspector.KeyboardShortcut.makeKeyFromEvent(event) !== this._shortcut.key)
             return false;
         this.toggleSearch();
         event.consume(true);
         return true;
     }
 }
 
 /** @type {!WebInspector.InspectElementModeController} */
 WebInspector.inspectElementModeController;