anchor.diff:    PlaygroundMobile() {
       _createUi();
       _initModules().then((_) => _initPlayground());
  +    _dartDoc = editor.document;
  +    _htmlDoc = editor.createDocument(content: '', mode: 'html');
  +    _cssDoc = editor.createDocument(content: '', mode: 'css');
     }
   
     void showHome(RouteEnterEvent event) {
  
positive.code:     // TODO: Add a real code completer here.
      //editorFactory.registerCompleter('dart', new DartCompleter());
  
      // Set up the gist loader.
      // TODO: Move to using the defaultFilters().
      deps[GistLoader] = new GistLoader();
  
      document.onKeyUp.listen((e) {
        if (editor.completionActive ||
            DocHandler.cursorKeys.contains(e.keyCode)) {
          docHandler.generateDocWithText(_docPanel);
        }
      });
  
      // Listen for changes that would effect the documentation panel.
      editor.onMouseDown.listen((e) {
  
negative.code:   DocHandler docHandler;
    String _gistId;
  
    bool get _isCompletionActive => editor.completionActive;
    
    Future createNewGist() {
      return null;
    }
  