<!DOCTYPE html>
<title>
  Adding a scrollable element should make it start capturing snap points.
</title>
<link rel="help" href="https://drafts.csswg.org/css-scroll-snap/#captures-snap-positions"/>
<meta name="viewport" content="user-scalable=no">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
div {
  position: absolute;
  margin: 0px;
}

html {
  scroll-snap-type: y mandatory;
}

body {
  margin: 0px;
}

#middle-scroller {
  top: 100px;
  