no-backing-foreground-layer.html | Explore in Territory

<!DOCTYPE html>

<html>
<head>
  <style>
    .container {
      position: relative;
      overflow: hidden;
      height: 190px;
      width: 200px;
      border: 1px solid black;
      z-index: 0;
    }

    .box {
      height: 100px;
      width: 100px;
      margin: -10px;
      background-color: blue;
    }

    .behind {
      position: absolute;
      top: 0;
      z-index: -1;
    }

    .composited {
      position: absolute;
      top: 50px;
      will-change: transform;
      background-color: green;
    }
  </style>
  <script>
    if (window.testRunner)
      testRunner.dumpAsText();
  </script>
</head>
<body>
  <p>This test should not ASSERT in debug builds.</p>
  <div class="container">
    <div class="behind box"></div>
    <div class="composited box"></div>
  </div>
</body>
</html>

chromium/third_party/blink/web_tests/compositing/backing/no-backing-foreground-layer.html