layout-width-change.html | Explore in Territory

<!DOCTYPE>
<html>
<head>
  <title>Layout width change</title>

  <style type="text/css" media="screen">
  .container {
    position: absolute;
    width: 400px;
    height: 1500px;
  }

  .panel {
    position: absolute;
    top: 0px;
    left: 0px;
    width: 1000px;
    height: 200px;
    background-color: #bbb;
  }

  .composited {
    will-change: transform;
  }
  </style>
  <script src="../resources/run-after-layout-and-paint.js"></script>
  <script type="text/javascript" charset="utf-8">
    function doTest()
    {
      var container = document.getElementById("container");
      var panel = document.getElementById("panel");

      runAfterLayoutAndPaint(function() {
         panel.className += " composited"
         container.style.height = "300";
      }, true);
    }

    window.addEventListener('load', doTest, false);
    </script>
</head>
<body>

  <p>There should be no white gap at the right hand side of the box.</p>
  <div id="container" class="container">
    <div id="panel" class="panel">
    </div>
  </div>

</body>
</html>

chromium/third_party/blink/web_tests/compositing/layout-width-change.html