diff -r 000000000000 -r 6474c204b198 xpcom/io/nsDirectoryServiceUtils.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/io/nsDirectoryServiceUtils.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsDirectoryServiceUtils_h___
+#define nsDirectoryServiceUtils_h___
+
+#include "nsIServiceManager.h"
+#include "nsIProperties.h"
+#include "nsServiceManagerUtils.h"
+#include "nsCOMPtr.h"
+#include "nsXPCOMCID.h"
+#include "nsIFile.h"
+
+inline nsresult
+NS_GetSpecialDirectory(const char* specialDirName, nsIFile* *result)
+{
+    nsresult rv;
+    nsCOMPtr<nsIProperties> serv(do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv));
+    if (NS_FAILED(rv))
+        return rv;
+
+    return serv->Get(specialDirName, NS_GET_IID(nsIFile),
+                     reinterpret_cast<void**>(result));
+}
+
+#endif