return CallQueryInterface(it, aResult);
NS_ADDREF(*aResult);  return NS_OK;
NS_NewDocumentViewer(nsIDocumentViewer** aResult){  NS_PRECONDITION(aResult, "null OUT ptr");  if (!aResult) {    return NS_ERROR_NULL_POINTER;  }  DocumentViewerImpl* it = new DocumentViewerImpl();  if (nsnull == it) {    *aResult = nsnull;    return NS_ERROR_OUT_OF_MEMORY;  }  return CallQueryInterface(it, aResult);}