chromium/third_party/blink/web_tests/external/wpt/html/links/stylesheet/quirk-origin-check.html

<!-- quirks -->
<title>Origin check for stylesheet with non-CSS MIME type quirk</title>
<link rel="stylesheet" href="data:text/plain,.test { background: red }">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<p class=test>There should be no red.</p>
<script>
setup({ single_test: true });
onload = () => {
  assert_equals(getComputedStyle(document.querySelector('.test')).backgroundColor, 'rgba(0, 0, 0, 0)');
  done();
};
</script>