Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/paint/invalidation/compositing/iframe-inside-squashed-layer.html 

<!DOCTYPE html>
<script src="../resources/text-based-repaint.js"></script>
<script>
function repaintTest() {
    window.frames['subframe'].contentDocument.body.style.height = '200px';
}
</script>
<body onload="runRepaintAndPixelTest()">
<div id="foo" style="width: 200px; height: 1000px; will-change: transform; background-color: lightgray;"></div>

<!-- The squashing layer will contain the following two divs. Note that the second is 100px lower than the top. -->
<div style="position: absolute; z-index: 0; top: 0px; width: 100px; height: 500px"></div>
<div style="position: absolute; z-index: 0; top: 500px; width: 100px; height: 100px">
  <iframe frameborder=0 id="subframe" srcdoc="test1">
  </iframe>
</div>
</body>