chromium/content/test/data/accessibility/language-detection/lang-attribute-nested.html

<!--
@BLINK-ALLOW:language=*
@WIN-ALLOW:language:*
@MAC-ALLOW:AXLanguage
-->
<!DOCTYPE html>
<html lang="en">
<body>
  <div lang="es-ES">
    <div lang="en">
      <span>
        This document is excellent.
      </span>
    </div>

    <span>
      Este documento es excelente.
    </span>
  </div>

  <div lang="fr">
    Ce document est excellent.
  </div>

  <span>
    This document is excellent.
  </span>

</body>
</html>