chromium/third_party/blink/web_tests/external/wpt/css/css-fonts/font-size-adjust-metrics-override-ref.html

<!DOCTYPE html>
<meta charset="utf-8">
<link rel="help" href="https://www.w3.org/TR/css-fonts-5/#font-size-adjust-prop">
<meta name="assert" content="Tests the simultaneous use of font-size-adjust and metrics override descriptorof of @font-face">
<title>Tests if font metric overrides reflect the adjustment of font-size-adjust.</title>
<style>
@font-face {
  font-family: Ahem;
  src: local(Ahem), url(/fonts/Ahem.ttf);
}

.reference {
  font: 20px Ahem;
  position: absolute;
  top: 10px;
  left: 10px;
}

.overridden-ascent-ref {
  display: inline-block;
  background-color: green;
  width: 1em;
  height: 1em; /* Scale a reference block to match the overridden ascent of 100%. */
}

.character {
  display: inline-block;
  background-color: green;
  width: 2em;  /* Double-size of an 'X' in Ahem */
  height: 2em; /* Double-size of an 'X' in Ahem */
  position: absolute;
  /* Two times of difference between the overridden ascent and the original ascent */
  top: 0.4em;
  left: 1em;
}

.overridden-descent-ref {
  display: inline-block;
  background-color: green;
  width: 1em;
  height: 0.5em; /* Scale a reference block to match the overridden descen of 50%. */
  position: absolute;
  top: 2.5em;
  left: 3em;
}

</style>
<!--
The three green rectangles below show ascent, character, and descent sizes
from the left. The ascent and descent are overridden by 100% and 50% of the
specified font size, respectively. The test applies font-size-adjust and font
metric overrides simultaneously to text. As we double the text size with
font-size-adjust, the ascent and descent override should scale accordingly
to double their size.
-->
<div class="reference">
  <span class="overridden-ascent-ref"></span><span class="character"></span><span class="overridden-descent-ref"></span>
</div>