chromium/chrome/test/data/android/url_overriding/navigation_from_page_show.html

<!DOCTYPE html>
<html>
<head>
  <script>
    document.addEventListener("visibilitychange", () => {
      if (document.visibilityState === "visible") {
        window.location = 'intent://test/#Intent;scheme=externalappscheme;end';
      }
    });
  </script>
</head>
<body>
  Redirect on show.
</body>
</html>