*aDoingPrintPreview = mIsDoingPrintPreview;
DocumentViewerImpl::GetDoingPrintPreview(PRBool *aDoingPrintPreview){  NS_ENSURE_ARG_POINTER(aDoingPrintPreview);  *aDoingPrintPreview = mIsDoingPrintPreview;  if (!*aDoingPrintPreview) {    nsCOMPtr<nsIWebBrowserPrint> wbp;    GetParentWebBrowserPrint(mContainer, getter_AddRefs(wbp));    if (wbp) {      return wbp->GetDoingPrintPreview(aDoingPrintPreview);    }  }  return NS_OK;}