Split gfxReusableSurfaceWrapper into gfxReusableSurfaceWrapper and
gfxReusableSharedImageSurfaceWrapper, to allow for non gfxSharedImage-based
implementations.
--HG--
rename : gfx/thebes/gfxReusableSurfaceWrapper.cpp => gfx/thebes/gfxReusableSharedImageSurfaceWrapper.cpp