chrome/browser/resources/options/secondary_user_banner.html

<div id="secondary-user-banner" class="settings-banner" hidden>
  <div class="content-area">
    <div class="badge"></div>
    <div class="text">
      <p>
        <span i18n-values=".innerHTML:secondaryUserBannerText">
        </span>
      </p>
    </div>
  </div>
</div>