tests/wpt/web-platform-tests/css/css-contain/contain-size-select-001.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Containment Test: Size containment on select</title>
<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
<link rel="help" href="https://drafts.csswg.org/css-contain-1/#containment-size">
<link rel="match" href="reference/contain-size-select-001-ref.html">
<meta name=assert content="<select> elements with 'contain: size' should be treated as having no contents.">
<style>
select {
  color: white;
  background: white;
  contain: size;
}
</style>
<p>Test passes if it has the same output than the reference.</p>
<select>
  <option>AVeryLongOption</option>
  <option>Another Option</option>
</select>