Import wpt@8c6d6497707871cf1c073bae65ae06102b569167

Using wpt-import in Chromium 2bd9927bb715c597e00c0674ce69880c93747eb3.
With Chromium commits locally applied on WPT:
d5cd6b98a6 "SharedWorker: Assign unique names to SharedWorkers to avoid unintentional matching"
acf3302037 "Add testing for the scrolling attribute"
1aeefa8811 "[UA client hints] Align implementation with PR#46, #48 & #70"


Note to sheriffs: 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/+/master/docs/testing/web_platform_tests.md

Directory owners for changes in this CL:
foolip@chromium.org, lpz@chromium.org, robertma@chromium.org:
  external/wpt/tools
foolip@chromium.org, robertma@chromium.org, smcgruer@chromium.org:
  external/wpt/infrastructure

NOAUTOREVERT=true
TBR=smcgruer

No-Export: true
Change-Id: I25ff300c5b0d4950eb1b2b20d3c9ab286a25e6e7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2089410
Reviewed-by: WPT Autoroller <wpt-autoroller@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: WPT Autoroller <wpt-autoroller@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#747919}