WPT import https://crrev.com/c/1084316 introduced new failures in external/wpt/css/css-ui:

List of new failures:
external/wpt/css/css-ui/outline-018.html new failing tests: https://crrev.com/c/1084316/4/third_party/WebKit/LayoutTests/external/wpt/css/css-ui/outline-018-expected.txt

This import contains upstream changes from 596c572f97a886dc7d8a3239737d42af161d4d9d to ee82278e15570e573d87fb80179ff8231b6db61a:
Merge pull request #11315 from web-platform-tests/importscripts-fix: https://github.com/web-platform-tests/wpt/commit/ee82278e15570e573d87fb80179ff8231b6db61a
Correct importScripts() behavior test: https://github.com/web-platform-tests/wpt/commit/15951e21d241b665aa626dd53ab60a99617ab264
PaymentHandler: Fix a crash when creating event object with empty data: https://github.com/web-platform-tests/wpt/commit/1dc612f2ed6a6bec861a90ad9bfa9a4336165dcd
Revert "Cleanup plugin element frames when the layout tree is detached": https://github.com/web-platform-tests/wpt/commit/69a48d90cac792566f14d734d2bae4feda462829
HTML: Don't confuse test runner by including testharness.js in a popup: https://github.com/web-platform-tests/wpt/commit/dcc00e1d0f88a98e30b75cc31d44be6cdfea0ae1
Make dynamic-import tests fail early instead of time out: https://github.com/web-platform-tests/wpt/commit/04cea7f3ce951cf78542e9dfd8621b35ff4c284e
Update outline-017.html & 018 to reduce flakiness in Edge: https://github.com/web-platform-tests/wpt/commit/bbb74f35348e0cd99c5d7b33052122a9c8d01dfa [affecting this directory]
Sync Mozilla tests as of https://hg.mozilla.org/mozilla-central/rev/9900cebb1f9000bd05731ba67736b7c51f7eb812 . (#11283): https://github.com/web-platform-tests/wpt/commit/748214c9a473c1f2c98455a43353a1832722ce55 [affecting this directory]
fixup! [mediacapture] Simply test and use standard API: https://github.com/web-platform-tests/wpt/commit/135d656fb17b99a9bf0e91667b8036b80f2c4d65
[mediacapture] Simply test and use standard API: https://github.com/web-platform-tests/wpt/commit/d2a2ea62ec000ff6d5c1572ba62a089eeb69e0c4
[css-layout-api] Adds passing of LayoutConstraints#fixedBlockSize.: https://github.com/web-platform-tests/wpt/commit/ff4d0553835102b2f68c7bf8dafb205bd3cacb89 [affecting this directory]
Move add_dependency_idls after add_idls (#11305): https://github.com/web-platform-tests/wpt/commit/197cdad0521ac04c0057b45ec92ddb3bca68ae19