chrome/browser/resources/options/startup_section.html

<section id="startup-section" guest-visibility="hidden">
  <h3 i18n-content="sectionTitleStartup"></h3>
  <div>
    <div class="radio">
      <span class="controlled-setting-with-label">
        <input id="startup-newtab" type="radio" name="startup" value="5"
            pref="session.restore_on_startup"
            metric="Options_Startup_NewTab">
        <span>
          <label for="startup-newtab" i18n-content="startupShowNewTab"></label>
          <span class="controlled-setting-indicator"
              pref="session.restore_on_startup" value="5">
          </span>
        </span>
      </span>
    </div>
    <div class="radio">
      <span class="controlled-setting-with-label">
        <input id="startup-restore-session" type="radio" name="startup"
            value="1" pref="session.restore_on_startup"
            metric="Options_Startup_LastSession">
        <span>
          <label for="startup-restore-session"
              i18n-content="startupRestoreLastSession">
          </label>
          <span class="controlled-setting-indicator"
              pref="session.restore_on_startup" value="1">
          </span>
        </span>
      </span>
    </div>
    <div class="radio">
      <span class="controlled-setting-with-label">
        <input id="startup-show-pages" type="radio" name="startup"
            pref="session.restore_on_startup"
            value="4" metric="Options_Startup_Custom">
        <span>
          <label for="startup-show-pages" i18n-content="startupShowPages">
          </label>
          <span class="controlled-setting-indicator"
              pref="session.restore_on_startup" value="4">
          </span>
          <button id="startup-set-pages" class="link-button"
              i18n-content="startupSetPages">
          </button>
          <span class="controlled-setting-indicator"
              pref="session.startup_urls">
          </span>
        </span>
      </label>
    </div>
  </div>
</section>