mozilla-release/layout/reftests/forms/input/number/number-similar-to-text-unthemed-vertical-lr.html

<!DOCTYPE html>
<html style="writing-mode:vertical-lr;">
  <body>
    <input type="number" style="-moz-appearance:none; height:200px;" value="123">
    <!-- div to cover spin box area -->
    <div style="position:absolute; background-color:black; width:100px; height:200px; top:100px; left:0px;">
  </body>
</html>