For the coexistence of SurfaceView and TextureView, I didn't ever have a try, it is supposed to be fine. But obviously, it will introduce complex for the embedding API, I am not sure if it will cause some graphics issue. More important, I don't see such an usage scenario to need such a coexistence, if the Crosswalk user request it in future, we can easily turn it on. So as the first stage, I recommend to keep the API simple.