webcodecs: Fix plane size for VideoFrames that transfer ArrayBuffers
Before this change we would lose the last row of I420 frames with an odd
number of rows.
Bug: 379066963
Change-Id: I19c1459984645eda718e7e84fd3ccb773fea1f45
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6026685
Reviewed-by: Dale Curtis dalecurtis@chromium.org
Commit-Queue: Eugene Zemtsov eugene@chromium.org
Cr-Commit-Position: refs/heads/main@{#1383923}