Sync web-platform-tests PR 37911 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/37911
Details from upstream follow.

Fredrik Söderquist <fs@opera.com> wrote:

Fix substitution in wpt/css/css-values/urls/resolve-relative-to-base.html

This test appears to want to use a \<base> element to specify a base URL
for the document. It does so using the substitution syntax ({{...}}).
However it does not tell the server to perform substitution. The test
could pass as-is though depending on what document.baseURI returns given
an invalid href. In Blink however document.baseURI returns 'about:blank'
in this case[1], and thus the resolution of the reference URL in the
test fails. This test shouldn't rely on this though.

Rename the test to add the .sub. part of the filename that triggers
substitution.

[1] The WPT for that is html/semantics/document-metadata/the-base-element/base_href_invalid.html

Bug: 1219803
Change-Id: I80cfe9a253aa5db8e80ffa8af99737fa6872e369

Reviewed-on: https://chromium-review.googlesource.com/4161440
WPT-Export-Revision: 5ce91ef851a194a8973ebcc81eb8d85b298b8808

CI Results

Ran 9 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: 2

Links

Gecko CI (Treeherder)
GitHub PR Head
GitHub PR Base

https://hg.mozilla.org/mozilla-central/rev/14e80bdc571a