chromium/content/test/data/accessibility/css/transform.html

<!--
@BLINK-ALLOW:pageLocation=*
@WIN-ALLOW:location=*
@UIA-WIN-ALLOW:BoundingRectangle=(0, 50,*
@MAC-ALLOW:LocalPosition

The closing parenthesis is intentionally omitted from WAIT-FOR because UIA
represents location as part of BoundingRectangle which has four coordinates.
@BLINK-WAIT-FOR:(0, 50
@WIN-WAIT-FOR:(0, 50
@UIA-WIN-WAIT-FOR:(0, 50
@MAC-WAIT-FOR:{x: 0, y: 50}
-->
<!DOCTYPE html>
<html>
<head>
<style>
div, p {
  margin: 0;
  padding: 0;
  border: 0;
  top: 0;
  left: 0;
}
div {
  position: fixed;
}
#outer {
    transform: TranslateY(2px);
}
</style>
</head>
<body>

<div id="outer">
  <p>content</p>
</div>

<script>
  setTimeout(function() {
    document.getElementById("outer").style.transform = "translateY(50px)";
  }, 10);
</script>
</body>
</html>