diff -r 000000000000 -r 6474c204b198 dom/interfaces/events/nsIDOMNSEvent.idl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/interfaces/events/nsIDOMNSEvent.idl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "domstubs.idl"
+
+%{C++
+#ifdef ERROR
+#undef ERROR
+#endif
+%}
+
+[scriptable, uuid(2580b4a2-6d85-4ca6-9be2-98f3406ad296)]
+interface nsIDOMNSEvent : nsISupports
+{
+  const long ALT_MASK     = 0x00000001;
+  const long CONTROL_MASK = 0x00000002;
+  const long SHIFT_MASK   = 0x00000004;
+  const long META_MASK    = 0x00000008;
+};