_test (async () => {
    // Reset scroll state.
    scroller.scrollTo(0, 0);
    await waitForCompositorCommit();
    scroll_end_arrived = false;
    scroll_arrived_after_scroll_end = false;

    await touchFlingInTarget(50, scroller, 'down');
    // Wait for the scroll snap animation to finish.
    await waitForAnimationEnd(scrollTop);
    await waitFor(() => { return scroll_end_arrived; });
    // Verify that scroll snap animation has finished before firing scrollend event.
    assert_false(scroll_arrived