Import wpt@5d15ed08d41e791b2bcf65b8c7c7a263853d382c

https://github.com/web-platform-tests/wpt/compare/d1b4f7aab...5d15ed08d

Using wpt-import in Chromium dc8454f5.
With Chromium commits locally applied on WPT:
  256090d9 "Reland "Cross-origin support for [...]

Note to gardeners: This CL imports external tests and adds expectations
for those tests; if this CL is large and causes a few new failures,
please fix the failures by adding new lines to TestExpectations rather
than reverting. See:
https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md

Directory owners for changes in this CL:
futhark@chromium.org, andruud@chromium.org:
  external/wpt/css/css-cascade

NOAUTOREVERT=true
R=rubber-stamper@appspot.gserviceaccount.com

No-Export: true
Validate-Test-Flakiness: skip
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Change-Id: I4df99df8f5a6b073e4342496ec46a486dcae82a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5435973
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: WPT Autoroller <wpt-autoroller@chops-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1283987}