WPT import https://crrev.com/c/1252858 introduced new failures in external/wpt/css/css-backgrounds:

List of new failures:
external/wpt/css/css-backgrounds/border-image-width-008.html [ Failure ]

This import contains upstream changes from 5d5c7170e3d6cd58a4a09780d371eaaffcdc248b to 138337bf938623dbda7c90cbcab3e49aa8a52c0d:
Merge pull request #13268 from web-platform-tests/sync_4819df38136e987f67beb805f523636e84876092: https://github.com/web-platform-tests/wpt/commit/138337bf938623dbda7c90cbcab3e49aa8a52c0d
Merge pull request #13267 from web-platform-tests/sync_63df09482d5de0087f766774f9b58815540704b6: https://github.com/web-platform-tests/wpt/commit/ead79336e78ca821061c2d58b09a57f911536dba
Layout: stylistic changes: https://github.com/web-platform-tests/wpt/commit/4819df38136e987f67beb805f523636e84876092 [affecting this directory]
Improve border images: https://github.com/web-platform-tests/wpt/commit/63df09482d5de0087f766774f9b58815540704b6 [affecting this directory]
[css-flexbox] Move a min-size: auto testcase to WPT: https://github.com/web-platform-tests/wpt/commit/54385744d834d6a9663c565d9bf2e979282a8a68 [affecting this directory]
Ensure that we establish an overflow clip on paint containment.: https://github.com/web-platform-tests/wpt/commit/b949365f277286071a0368f69091f6303164f99f [affecting this directory]
RTCQuicTransport: start() implementation: https://github.com/web-platform-tests/wpt/commit/1931a2758eef0ba57f7f3f6608baf0082a4e1bb3
[IntersectionObserver] Report coordinates as CSS pixels.: https://github.com/web-platform-tests/wpt/commit/0d51e91a0b57a591adf3341d2ab6823d6588ede7