anchor.diff:      // TODO(ussuri): Check the sender?
       if (event.message['type'] == 'export_code_response') {
         _codeExported.complete("${event.message['code']}");
  -      // Null the completer so new [getCode] requests can work properly. 
  +      // Null the completer so new [getCode] requests can work properly.
         _codeExported = null;
       }
     }
   
     /**
  -   * Registers a listener for responses sent by [_designerProxy]. 
  +   * Registers a listener for responses sent by [_designerProxy].
      */
     void _registerDesignerProxyListener() {
       chrome.runtime.onMessage.listen(_designerProxyListener);
  
positive.code:   /// script injected into it.
    Completer _webviewReady;
    /// Fires when the asynchronous code export requested from the proxy has
    /// completed. 
    Completer<String> _codeExported;
  
    CdePolymerDesigner.created() : super.created();
  
negative.code:   }
  
    /**
     * Tweaks the Polymer Designer UI and inject a proxy script.
     */
    void _onWebviewContentLoad(_) {
      _tweakDesignerUI();
  