custom-scrollbar-appearance-property.html

<!DOCTYPE html>
<html>
<head>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>
<script src="../resources/run-after-layout-and-paint.js"></script>
<style>
::-webkit-scrollbar {
    width: 16px;
    height: 16px;
    -webkit-appearance: button;
}

::-webkit-scrollbar-track {
    background-color: #E3E3E3;
    -webkit-appearance: button;
}

::-webkit-scrollbar-thumb {
    background: black;
}

.scroll-container {
    overflow: scroll;
    width: 50px;
    height: 50px;
}

.overflowing {
    width: 200px;
    height: 200px;
}
</style>
</head>
<body>
PASS if not crashed.
<div class="scroll-container"><div class="overflowing"></div></div>
<script>
async_test(t => {
  runAfterLayoutAndPaint(t.step_func_done(() => {}));
}, 'Do not crash if -webkit-scrollbar* has -webkit-appearance:button');
</script>
</body>
</html>

chromium/third_party/blink/web_tests/scrollbars/custom-scrollbar-appearance-property.html