Id("inner-scroller");
const middle_scroller = document.getElementById("middle-scroller");
const document_scroller = document.scrollingElement;

// This tests that making an element scrollable will reassign the correct snap
// areas to itself, per spec [1].
// [1] https://drafts.csswg.org/css-scroll-snap/#captures-snap-positions
test(() => {
  // Confirm that the document-level scroller is the snap container for all of
  // the snap areas.
  document_scroller.scrollTo(0, 10);
  assert_equals(document_scrolle