chromium/content/test/data/accessibility/html/offscreen-select.html

<!--
@WIN-ALLOW:OFFSCREEN
@BLINK-ALLOW:offscreen
-->

<html>
<body>
  <!-- Test when list box items are onscreen
    Currently collapsed <option> elements are treated as onscreen, but this
    probably isn't the most correct behavior, we should fix it.
    http://crbug.com/937386 -->
  <select name="Select onscreen">
    <option value="1">Onscreen 1</option>
    <option value="2">Onscreen 2</option>
    <option value="3">Onscreen 3</option>
  </select>

  <div style="height:650px"></div>

  <!-- Test when list box items are offscreen -->
  <select name="Select offscreen">
    <option value="1">Offscreen 1</option>
    <option value="2">Offscreen 2</option>
    <option value="3">Offscreen 3</option>
  </select>
</body>
</html>