chromium/third_party/blink/web_tests/fast/css/bfc-percentage-margin-expected.html

<!DOCTYPE html>
<style>
#container {
    position: relative;
}
.square {
    width: 100px;
    height: 100px;
    background-color: blue;
    position: absolute;
}
.right {
    left: 120px;
}
</style>
<p>You should see two blue squares below.</p>
<div id="container">
    <div class="square"></div>
    <div class="square right"></div>
</div>