diff -r 000000000000 -r 6474c204b198 content/canvas/src/WebGLContextNotSupported.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/canvas/src/WebGLContextNotSupported.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,10 @@
+/* -*- 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 "nsIDOMWebGLRenderingContext.h"
+
+#define DUMMY(func,rtype)  nsresult func (rtype ** aResult) { return NS_ERROR_FAILURE; }
+
+DUMMY(NS_NewCanvasRenderingContextWebGL, nsIDOMWebGLRenderingContext)