buffer.Append("directory unavailable");
buffer.AppendLiteral("directory unavailable");
NS_IMETHODIMP nsDiskCacheDeviceInfo::GetUsageReport(char ** usageReport){    NS_ENSURE_ARG_POINTER(usageReport);    nsCString buffer;        buffer.Append("\n<tr>\n<td><b>Cache Directory:</b></td>\n<td><tt> ");    nsCOMPtr<nsILocalFile> cacheDir;    nsAutoString           path;    mDevice->getCacheDirectory(getter_AddRefs(cacheDir));     nsresult rv = cacheDir->GetPath(path);    if (NS_SUCCEEDED(rv)) {        AppendUTF16toUTF8(path, buffer);    } else {        buffer.Append("directory unavailable");    }    buffer.Append("</tt></td>\n</tr>\n");    // buffer.Append("<tr><td><b>Files:</b></td><td><tt> XXX</tt></td></tr>");    *usageReport = ToNewCString(buffer);    if (!*usageReport) return NS_ERROR_OUT_OF_MEMORY;    return NS_OK;}