Add Masonry Track Sizing Tests
Pull request: https://github.com/WebKit/WebKit/pull/8057
<rdar://problem/103787171>
Committed 258409@main (7a79101a21e1): <https://commits.webkit.org/258409@main> Reviewed commits have been landed. Closing PR #8057 and removing active labels.
Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/39766