chromium/third_party/blink/web_tests/external/wpt/webvtt/rendering/cues-with-video/processing-model/repaint-ref.html

<!DOCTYPE html>
<title>Reference for WebVTT rendering, cue should repaint after hiding a covering abspos box</title>
<style>
.video {
    display: inline-block;
    width: 320px;
    height: 240px;
    position: relative;
    font-size: 50px;
}
.cue {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    text-align: center
}
.cue > span {
    font-family: sans-serif;
    background: rgba(0,0,0,0.8);
    color: green;
}
</style>
<p>You should see the word 'PASS' below.</p>
<div class="video"><span class="cue"><span>PASS</span></span></div>