diff -r 000000000000 -r 6474c204b198 gfx/2d/DataSourceSurfaceWrapper.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/2d/DataSourceSurfaceWrapper.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 20; 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/. */
+
+#ifndef MOZILLA_GFX_DATASOURCESURFACEWRAPPER_H_
+#define MOZILLA_GFX_DATASOURCESURFACEWRAPPER_H_
+
+#include "2D.h"
+
+namespace mozilla {
+namespace gfx {
+
+// Wraps a DataSourceSurface and forwards all methods except for GetType(),
+// from which it always returns SurfaceType::DATA.
+class DataSourceSurfaceWrapper : public DataSourceSurface
+{
+public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DataSourceSurfaceWrapper)
+  DataSourceSurfaceWrapper(DataSourceSurface *aSurface)
+   : mSurface(aSurface)
+  {}
+
+  virtual SurfaceType GetType() const MOZ_OVERRIDE { return SurfaceType::DATA; }
+
+  virtual uint8_t *GetData() MOZ_OVERRIDE { return mSurface->GetData(); }
+  virtual int32_t Stride() MOZ_OVERRIDE { return mSurface->Stride(); }
+  virtual IntSize GetSize() const MOZ_OVERRIDE { return mSurface->GetSize(); }
+  virtual SurfaceFormat GetFormat() const MOZ_OVERRIDE { return mSurface->GetFormat(); }
+  virtual bool IsValid() const MOZ_OVERRIDE { return mSurface->IsValid(); }
+
+private:
+  RefPtr<DataSourceSurface> mSurface;
+};
+
+}
+}
+
+#endif /* MOZILLA_GFX_DATASOURCESURFACEWRAPPER_H_ */