The diff capturer wrapper doesn't work if the frame doesn't have any rectangle and a static image is observed while chromoting. This change adds a rectangle to the frame object, as done by other capturers, and this in turn ensures that the wrapper that calulcates diffs from one frame to the next can do its job. Bug: chromium:1291247 Change-Id: I5bf1981f34b3a88ad4d82a081fed1ce210f71ed0 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/251205 Reviewed-by: Alexander Cooper <alcooper@chromium.org> Commit-Queue: Salman Malik <salmanmalik@google.com> Cr-Commit-Position: refs/heads/main@{#36263}