1<!DOCTYPE html>
2<html>
3<head>
4<script src="/resources/testharness.js"></script>
5<script src="/resources/testharnessreport.js"></script>
6<script src="/resources/testdriver.js"></script>
7<script src="/resources/testdriver-actions.js"></script>
8<script src="/resources/testdriver-vendor.js"></script>
9<style>
10
11body { margin: 0; padding: 10px; }
12.space { height: 2000px; }
13
14#scroller {
15  border: 3px solid green;
16  position: absolute;
17  z-index: 0;
18  overflow: auto;
19  padding: 10px;
20  width: 250px;
21  height: 150px;
22}
23
24.ifr {
25  border: 3px solid blue;
26  width: 200px;
27  height: 100px;
28}
29
30</style>
31</head>
32<body>
33<div id=scroller>
34  <iframe srcdoc="SCROLL ME" class=ifr></iframe>
35  <div class=space></div>
36</div>
37<div class=space></div>
38<script>
39
40promise_test(async t => {
41  await new test_driver.Actions().scroll(50, 50, 0, 50).send();
42  // Allow the possibility the scroll is not fully synchronous
43  await t.step_wait(() => scroller.scrollTop === 50);
44}, "Wheel scroll in iframe chains to containing element.");
45
46</script>
47</body>
48</html>
49