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chromium/third_party/blink/web_tests/external/wpt/html/semantics/forms/the-selectlist-element/selectlist-marker-visible-overflow-ref.tentative.html 

<!DOCTYPE html>
<style>
selectlist {
  width:100px;
}
</style>
<div>
<selectlist>
  <option>&nbsp;</option>
</selectlist>