diff -r 000000000000 -r 6474c204b198 gfx/gl/SharedSurface.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/gl/SharedSurface.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,29 @@
+/* -*- Mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40; -*- */
+/* 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 "SharedSurface.h"
+#include "SharedSurfaceGL.h"
+
+using namespace mozilla::gl;
+
+namespace mozilla {
+namespace gfx {
+
+// |src| must begin and end locked, though it
+// can be temporarily unlocked if needed.
+void
+SharedSurface::Copy(SharedSurface* src, SharedSurface* dest, SurfaceFactory* factory)
+{
+    MOZ_ASSERT( src->APIType() == APITypeT::OpenGL);
+    MOZ_ASSERT(dest->APIType() == APITypeT::OpenGL);
+
+    SharedSurface_GL* srcGL = (SharedSurface_GL*)src;
+    SharedSurface_GL* destGL = (SharedSurface_GL*)dest;
+
+    SharedSurface_GL::ProdCopy(srcGL, destGL, (SurfaceFactory_GL*)factory);
+}
+
+} /* namespace gfx */
+} /* namespace mozilla */