chrome/browser/resources/chromeos/login/screen_fatal_error.html

<div id="fatal-error" class="step hidden" hidden>
  <div class="step-contents">
    <div id="fatal-error-message-container">
      <img src="chrome://theme/IDR_FATAL_ERROR"><br>
      <p>
        <span id="fatal-error-message"></span><br>
        <span i18n-content="fatalErrorInstructions"></span>
      </p>
    </div>
    <div id="fatal-error-button-strip">
      <div id="fatal-error-button-strip-space-filler"></div>
      <button id="fatal-error-dismiss-button"
          i18n-content="fatalErrorDismissButton"></button>
    </div>
  </div>
</div>