Summary: Notify the driver about the parts of the screen that will be repainted. In some cases this can be benefitial. This is especially useful on lima and panfrost devices (e.g. pinephone, pinebook, pinebook pro).
Test Plan: Tested on a pinebook pro with a late mesa version. Basically I implemented it, then it didn't work and I fixed it. Maybe next step we want to look into our damage algorithm.