Consumers expect the frame to be valid if Result::SUCCESS is delivered. If the frame is nullptr, we should deliver ERROR_TEMPORARY instead. Bug: webrtc:14265 Change-Id: If94a3ead38d7657d7b90bbe046256be697312216 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/269223 Commit-Queue: Mark Foltz <mfoltz@chromium.org> Reviewed-by: Mark Foltz <mfoltz@chromium.org> Cr-Commit-Position: refs/heads/main@{#37590}