chromium/third_party/blink/web_tests/css3/viewport-percentage-lengths/vh-resize.html

<!DOCTYPE html>
<html>
<head>
<script>
function init() {
      if (!window.testRunner)
          return;
      // Move the resizer 400 pixels down.
      eventSender.mouseMoveTo(100, 400);
      eventSender.mouseDown();
      eventSender.mouseMoveTo(100, 200);
      eventSender.mouseUp();

      // Also test when frame height is increased.
      eventSender.mouseMoveTo(100, 200);
      eventSender.mouseDown();
      eventSender.mouseMoveTo(100, 300);
      eventSender.mouseUp();
}
window.onload = init;
</script>
</head>
<frameset rows="400px,*">
<frame src="data:text/html,
    <style>
    div {
        width: 50vh;
        height: 50vh;
        background: #36C;
    }</style>
<div></div>
<p>Bug 86418: This tests that on resizing initial containing block vertically,
 element with 'vh' length gets resized.</p>
<p>Blue square should be half the height of frame height.</p>
"></frame>
<frame src=""></frame>
</frameset>
</html>