display-contents-slot-attach-whitespace.html

<!doctype html>
<title>Attaching shadow slot with assigned whitespace separated inline elements</title>
<link rel="help" href="https://drafts.csswg.org/css-display-3/#valdef-display-contents">
<link rel="help" href="https://drafts.csswg.org/css-text-3/#white-space-rules">
<link rel="match" href="../reference/pass_if_two_words.html">
<p>There should be a space between "two" and "words" below.</p>
<div id="host"><span>two</span> <span>words</span></div>
<script>
  host.offsetTop;
  host.attachShadow({mode:"open"}).innerHTML = "<slot></slot>";
</script>

chromium/third_party/blink/web_tests/external/wpt/css/css-display/display-contents-slot-attach-whitespace.html