chromium/third_party/blink/web_tests/css3/selectors3/xml/css3-modsel-14b.xml

<?xml-stylesheet href="css3-modsel-14b.css" type="text/css"?>
<test>
  <p xmlns="http://www.w3.org/1999/xhtml" class="t1">This line should be green.</p>
  <p xmlns="http://www.w3.org/1999/xhtml" class="t1 t2">This line should be green.</p>
</test>