diff -r 000000000000 -r 6474c204b198 gfx/thebes/gfxBaseSharedMemorySurface.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/thebes/gfxBaseSharedMemorySurface.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+// vim:set ts=4 sts=4 sw=4 et cin:
+/* -*- Mode: C++; tab-width: 20; 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/. */
+
+#include "gfxBaseSharedMemorySurface.h"
+#include "cairo.h"
+
+const cairo_user_data_key_t SHM_KEY = {0};
+