chromium/third_party/blink/web_tests/external/wpt/css/css-display/display-flow-root-002.html

<!DOCTYPE HTML>
<meta charset="utf-8">
<title>CSS Display Test: div with display: flow-root and zero width does not intersect outer floats</title>
<link rel="author" title="David Shin" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-display-3/#valdef-display-flow-root">
<link rel="help" href="https://www.w3.org/TR/CSS21/visuren.html#floats">
<link rel="match" href="display-flow-root-002-ref.html">
<style>
  .float {
    background-color: blue;
    width: 250px;
    height: 100px;
  }
  .left { float: left; }
  .right { float: right; }

  #outer { width: 400px; }

  #zerowidth {
    display: flow-root;
    width: 0;
    outline: 1px solid black;
    height: 200px;
  }
</style>
<div id="outer">
  <!-- Two floats are positioned and sized such that there is less than zero empty space "between" them. -->
  <div class="float right"></div>
  <div class="float left"></div>
  <div id="zerowidth"></div>
</div>