Implement timing mechanism to track what view matrices are used for each client frame #12
Description
Right now the compositor basically blindly sends view matrices to the clients each frame and then draws whatever buffer is most recently available for that client, with no knowledge of how out of date the view matrix is for that frame or how much the client's apparent transform has changed in that time.
This issue exists to track implementing a timing mechanism for view matrices and frames. So each view matrix from the compositor will come with a timestamp, and when the client notifies the compositor that it has drawn a new frame it also notifies it of the timestamp for the view matrices it drew that frame with. Then the compositor can keep track of relative motion of the client and could do things like a per-client time warp, or just drop client content if its too out of whack. In general it would just be good information to have for improving and optimizing the depth compositing process.