Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/compositing/squashing/iframes-are-never-squashed.html 

<!doctype html>

<div style="width: 200px; height: 200px; background: lightgray; will-change: transform"></div>
<iframe style="position: absolute; top: 0px; left: 0px; height: 100px; width: 100px; background: lightblue">
</iframe>
<script src="../../resources/run-after-layout-and-paint.js"></script>
<script>
if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.waitUntilDone();
    runAfterLayoutAndPaint(function() {
        testRunner.setCustomTextOutput(internals.layerTreeAsText(document));
        testRunner.notifyDone();
    });
}

</script>