docv->SetUAStyleSheet(nsContentDLF::GetUAStyleSheet());
docv->SetUAStyleSheet(NS_STATIC_CAST(nsIStyleSheet*, gUAStyleSheet));
nsContentDLF::CreateInstanceForDocument(nsISupports* aContainer,                                       nsIDocument* aDocument,                                       const char *aCommand,                                       nsIContentViewer** aDocViewerResult){  nsresult rv = NS_ERROR_FAILURE;    do {    nsCOMPtr<nsIDocumentViewer> docv;    // Create the document viewer    rv = NS_NewDocumentViewer(getter_AddRefs(docv));    if (NS_FAILED(rv))      break;    docv->SetUAStyleSheet(nsContentDLF::GetUAStyleSheet());    // Bind the document to the Content Viewer    rv = docv->BindToDocument(aDocument, aCommand);    *aDocViewerResult = docv;    NS_IF_ADDREF(*aDocViewerResult);  } while (PR_FALSE);  return rv;}