chrome/browser/resources/print_preview/previewarea/preview_area.html

<div id="preview-area" class="preview-area">
  <div class="preview-area-overlay-layer">
    <div class="preview-area-messages">

      <div class="preview-area-loading-message preview-area-message">
        <span i18n-content="loading"></span>
        <span class="preview-area-loading-message-jumping-dots jumping-dots"
            ><span>.</span><span>.</span><span>.</span></span>
      </div>

      <div class="preview-area-custom-message preview-area-message" hidden>
        <div class="preview-area-custom-message-text"></div>
        <div class="preview-area-custom-action-area">
          <button class="preview-area-open-system-dialog-button"
              i18n-content="launchNativeDialog"></button>
          <div class="preview-area-open-system-dialog-button-throbber throbber"
              hidden></div>
        </div>
      </div>

      <div class="preview-area-preview-failed-message preview-area-message"
          i18n-content="previewFailed" hidden></div>

      <div class="preview-area-print-failed preview-area-message" hidden>
        <div i18n-content="invalidPrinterSettings"></div>
        <div class="preview-area-print-failed-action-area">
          <button class="preview-area-open-system-dialog-button"
              i18n-content="launchNativeDialog"></button>
          <div class="preview-area-open-system-dialog-button-throbber throbber"
              hidden></div>
        </div>
      </div>

    </div>
  </div>
  <div class="preview-area-plugin-wrapper">
    <object class="preview-area-compatibility-object"
        type="application/x-google-chrome-print-preview-pdf"
        data="chrome://print/dummy.pdf"></object>
    <object class="preview-area-compatibility-object-out-of-process"
        type="application/x-google-chrome-pdf"
        data="chrome://print/dummy.pdf"></object>
  </div>
</div>