chromium/third_party/blink/web_tests/external/wpt/css/css-contain/contain-size-fieldset-001.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Containment Test: Size containment on fieldset</title>
<link rel="author" title="Manuel Rego Casasnovas" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-contain-1/#containment-size">
<link rel="match" href="reference/contain-size-fieldset-001-ref.html">
<meta name=assert content="Size containment does apply to fieldsets, thus their size is the same than if they don't have contents.">
<style>
fieldset {
  contain: size;
  display: inline-block;
  color: transparent;
  border: none;
  padding: 0;
}
</style>

<p>This test passes if it has the same output as the reference. You see the word "before", a small space, and then the word "after".</p>
before<fieldset><legend>legend</legend></fieldset>after