<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/web-animations-1/#the-effecttiming-dictionaries">
<style>
.scroller {
overflow: auto;
height: 100px;
width: 100px;
will-change: transform;
}
.contents {
height: 1000px;
width: 100%;
}
</style>
<div class="scroller">
<div class="contents"></div>
</div>
<script>
// Test passes if it does not crash.
// Scroll timeline animations are progress-based and not compatible with
// delays specified in milliseconds.
const timeline = new ScrollTimeline();
const options = {
timeline: timeline,
endDelay: 200
};
const keyframes = { opacity: [0, 1]};
const element = document.querySelector('.contents');
element.animate(keyframes, options);
</script>