Sync web-platform-tests PR 25442 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/25442
Details from upstream follow.

b'Joey Arhar <jarhar@chromium.org>' wrote:

Fix defaultValue-clobbering.html

I originally wrote this test in chromium using chromium's separate wpt
test runner, but it turns out that the test was timing out on wpt's
actual test runner, likely due to using a reftest and testdriver at the
same time.
This patch tests the same behavior in a different way and doesn't use
reftesting so the test doesn't time out anymore.

CI Results

Ran 12 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 1 tests and 2 subtests

Status Summary

Firefox

OK : 1
PASS: 2

Chrome

OK : 1
PASS: 2

Safari

OK : 1
PASS: 1
FAIL: 1

Links

Gecko CI (Treeherder)
GitHub PR Head
GitHub PR Base