diff -r 000000000000 -r 6474c204b198 xpcom/base/nsVersionComparatorImpl.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/base/nsVersionComparatorImpl.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+/* 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/. */
+
+#include "mozilla/Attributes.h"
+
+#include "nsIVersionComparator.h"
+
+class nsVersionComparatorImpl MOZ_FINAL : public nsIVersionComparator
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIVERSIONCOMPARATOR
+};
+
+#define NS_VERSIONCOMPARATOR_CONTRACTID "@mozilla.org/xpcom/version-comparator;1"
+
+// c6e47036-ca94-4be3-963a-9abd8705f7a8
+#define NS_VERSIONCOMPARATOR_CID \
+{ 0xc6e47036, 0xca94, 0x4be3, \
+  { 0x96, 0x3a, 0x9a, 0xbd, 0x87, 0x05, 0xf7, 0xa8 } }