LayoutTests/fast/media/use-system-appearance-user-stylesheet-parsing.html

<script src="../../resources/js-test-pre.js"></script>
<div id=test></div>
<script>
testRunner.addUserStyleSheet("@media (prefers-dark-interface) { #test { color: green } }", true);
testRunner.addUserStyleSheet("@media not screen and (prefers-dark-interface) { #test { color: green } }", true);

shouldBeEqualToString("getComputedStyle(test).color", "rgb(0, 0, 0)");
internals.setUseSystemAppearance(true);
shouldBeEqualToString("getComputedStyle(test).color", "rgb(0, 128, 0)");
internals.setUseSystemAppearance(false);
shouldBeEqualToString("getComputedStyle(test).color", "rgb(0, 0, 0)");
</script>
<script src="../../resources/js-test-post.js"></script>