[EncodedTransform] Add WPT for owner of the frames (#47889)
Implement a WPT to test the logic ensuring that only frames previously read by the same owner can be written.
Additionally, moved function appendToBuffer to a helper.
Bug: 354881878
Change-Id: I5db43b3e1dac1c0f243c0a7126b6fc2e5091af50
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5827535
Reviewed-by: Guido Urdaneta guidou@chromium.org
Reviewed-by: Palak Agarwal agpalak@chromium.org
Commit-Queue: Lucía Alonso Mozo alonsomozol@google.com
Cr-Commit-Position: refs/heads/main@{#1349215}
Co-authored-by: Lucia alonsomozol@google.com