chromium/content/test/data/gpu/pixel_render_passes.html

<!DOCTYPE HTML>
<html>
<head>
<meta name="viewport" content="initial-scale=1">
<title>Basic RenderPasses Test: masks/clipping/rounded corners</title>
<style type="text/css">
img {
  transform: translateZ(0) rotate(0.15turn);
  border-radius: 30px;
  filter: blur(1px);
}
</style>
<script>

var g_swapsBeforeAck = 50;

function waitForFinish()
{
  if (g_swapsBeforeAck == 0) {
    domAutomationController.send("SUCCESS");
  } else {
    g_swapsBeforeAck--;
    window.requestAnimationFrame(waitForFinish);
  }
}

function main()
{
  waitForFinish()
}

</script>
</head>

<body onload="main()" style="display:inline-flex; background: grey; margin-top: 15px; margin-left: 30px;">
  <img src='single_face.jpg'>
  <iframe width="140" height="140" frameBorder="0" scrolling="no"
          style="border-radius: 25px; margin-left: 30px;"
          title="Iframe Example1"
          src="render_passes/helper_render_passes_rounded_corners_iframe.html">
  </iframe>
  <iframe width="140" height="140" frameBorder="0" scrolling="no"
          style="border-radius: 5px; margin-left: 15px;"
          title="Iframe Example1"
          src="render_passes/helper_render_passes_clipping_iframe.html">
  </iframe>
</body>
</html>