chromium/third_party/blink/web_tests/fast/events/middleClickAutoscroll-click.html

<!DOCTYPE html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../../resources/gesture-util.js"></script>
<script src="../../resources/compositor-controls.js"></script>
<script src="./resources/middleClickAutoscroll.js"></script>
<style type="text/css">
#scrollable {
  height: 200px;
  overflow: auto;
  border: solid 3px #cc0000;
  font-size: 80px;
}
</style>
<script>
function start() {
  testSetUp({
    'clickOrDrag': 'click',
    'scrollable': $('scrollable'),
  });
}
</script>

<body onload="start()">
<div id="container">
<p id="description"></p>
For manual testing, click middle button in scrollable and move around mouse pointer for scrolling, then click middle button again to stop scrolling.
<div id="scrollable"></div>
</div>
<div id="console"></div>
</body>