BB 41454: Move focus after calling openPreferences for a sub-category.

  }

  let header = getClosestDisplayedHeader(element);

  // We assign a tabindex=-1 to the element so that we can focus it. This allows

  // us to move screen reader's focus to an arbitrary position on the page.

  // See tor-browser#41454 and mozilla bug 1799153.

  const doFocus = () => {

    element.setAttribute("tabindex", "-1");

    Services.focus.setFocus(element, Services.focus.FLAG_NOSCROLL);

    // Immediately remove again now that it has focus.

    element.removeAttribute("tabindex");

  };

  // The element is not always immediately focusable, so we wait until document

  // load.

  if (document.readyState === "complete") {

    doFocus();

  } else {

    // Wait until document load to move focus.

    // NOTE: This should be called after DOMContentLoaded, where the searchInput

    // is focused.

    window.addEventListener("load", doFocus, { once: true });

  }

  scrollContentTo(header);

  element.classList.add("spotlight");

}