chromium/third_party/blink/web_tests/compositing/squashing/do-not-squash-non-self-painting-layer.html

<!DOCTYPE html>

<html>
  <head>
    <script>
      if (window.testRunner)
        testRunner.dumpAsText();

      window.onload = function() {
        document.getElementById("item-body").style.display = "block";

        function runTest() {
          var pre = document.createElement('pre');
          if (!window.internals) {
            var description = "This test ensures non-self-painting elements don't"
              + "get squashed.";
            pre.innerHTML = description;
          } else {
            document.body.offsetTop;
            pre.innerHTML = internals.layerTreeAsText(document);
          }
          document.body.appendChild(pre);
        }

        runTest();
      };
    </script>
    <style>
      .container {
        overflow: auto;
      }

      #floated-container {
        float: left;
        height: 100px;
        overflow: auto;
      }

      #composited-container {
        backface-visibility: hidden;
      }

      #empty-block {
        height: 200px;
      }

      #item-body {
        display: none;
        background-color: blue;
        height: 40px;
        width: 40px;
      }
    </style>
  </head>

  <body>

    <div id="composited-container">
      <div id="floated-container">
        <div id="empty-block"></div>
      </div>
    </div>

    <div id="content-container" class="container">
      <div id="item-title">Item 1</div>
      <div id="item-body"></div>
    </div>

  </body>
</html>