LayoutTests/fast/ruby/ruby-with-out-of-flow-base-content.html

<style>
body {
  font-family: Ahem;
  font-size: 20px;
}
</style>
<div>X<ruby><rb style="position: absolute">XXX</rb></ruby></div>
<div>X<ruby><rb><span style="position: absolute">XXX</rb></ruby></div>