chromium/third_party/blink/web_tests/animations/stability/background-shorthand-crash.html

<!DOCTYPE html>
<style>
body {
    background: url('a'), url('b');
    animation: test 1s;
}

@keyframes test {
    to { background: url('a'), url('b'); }
}
</style>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>
var test = async_test("Test passes if it does not crash with background shorthand");
requestAnimationFrame(test.step_func_done(() => {}));
</script>