LayoutTests/fast/inline/fallback-font-with-line-spacing.html

<style>
div {
  font-height: 40px;
  color: green;
  background-color: green;
  width: 100px;
}
</style>
<!-- Use the line-gap font metrics when computing the layout bounds of the inline box (specifically with font-fallbacks) -->
<div><span>⇩</span></div>