Import wpt@6b9fbc6b8670159db226e6edee0712caa1378029

Using wpt-import in Chromium 1e7b8b561cd50dfa27f80f4dab7a2ad4418a417a.
With Chromium commits locally applied on WPT:
e28269b698 "[LayoutNG/PE] Clear visual overflow for LayoutText before setting."
aff3c8feca "Add tests for crbug.com/363609 and crbug.com/954591"
c4dc34414b "[WPT] Reland Upload a test for sending mouse events with key pressed"
a383507b32 "[UserTimingL3] Enable L3 in web tests; setup virtual tests for L2"


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

NOAUTOREVERT=true
TBR=kyleju

No-Export: true
Change-Id: I318787c68896e69f442f5cb09f9f074a5212f65c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1591472
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@{#655562}