Comment 5 for bug 1308345

i like alberto's idea, callback on occluded surface - and use demo code to vet it.

altho, it is fair to point out, using a side channel is "laggy" in the sense that the client may render a few more frames before actually stopping. altho, one could also argue there may be need (hence why we're moving the responsibility, mir shouldn't know the business of app render states)

@ duflu - on the topic of "I have a plan that I think everyone would find agreeable". Please share the idea with the team or on mir-devel before getting too crazy with the idea spending implementation energy on something that might be a no-go.