We already communicated SPA_META_VideoDamage before, but we never used these metadata. This change checks whether SPA_META_VideoDamage metadata are available and construct a damage rect combined from all sent damage regions. Bug: webrtc:13429 Change-Id: I326109b4bacf51855904e53345c671640d670323 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/278820 Reviewed-by: Alexander Cooper <alcooper@chromium.org> Commit-Queue: Jan Grulich <grulja@gmail.com> Cr-Commit-Position: refs/heads/main@{#38449}