css-anchor-position: Fix inset-area behavior in the sideways-lr wirting-mode
This CL fixes WritingDirectionMode::IsFlippedY(), and improves test
coverage.
Bug: 40501131
Change-Id: I1ef0181037eab3e8bd0ffbdbfac8b40b64b23116
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5736708
Commit-Queue: Koji Ishii kojii@chromium.org
Auto-Submit: Kent Tamura tkent@chromium.org
Reviewed-by: Koji Ishii kojii@chromium.org
Cr-Commit-Position: refs/heads/main@{#1332416}