viewport-percentage-lengths-scaled-overlay-scrollbars.html

<!DOCTYPE>
<html>
<script>
if (window.internals)
    internals.useMockOverlayScrollbars();
</script>
<style>
 #element-container-vw-vh {
   background: green;
   height: 50vh;
   width: 50vw;
 }
</style>
<script>
if (window.testRunner)
    testRunner.dumpAsText();
if (window.eventSender)
    internals.setPageScaleFactor(1.5);

function test()
{
    var div = document.getElementById("element-container-vw-vh");
    div.innerText = div.offsetWidth == 400 && div.offsetHeight == 300 ? "PASS" : "FAIL";
}
</script>

<body onload="test()">
<div id="element-container-vw-vh">Viewport Percentage Lengths</div>
</body>
</html>

chromium/third_party/blink/web_tests/css3/viewport-percentage-lengths/viewport-percentage-lengths-scaled-overlay-scrollbars.html