gitlab-org--gitlab-foss/app/views/layouts/_user_styles.html.haml

:css
  [data-user-is] {
    display: none !important;
  }

  [data-user-is="#{current_user.try(:id)}"] {
    display: block !important;
  }

  [data-user-is="#{current_user.try(:id)}"][data-display="inline"] {
    display: inline !important;
  }

  [data-user-is-not] {
    display: block !important;
  }

  [data-user-is-not][data-display="inline"] {
    display: inline !important;
  }

  [data-user-is-not="#{current_user.try(:id)}"] {
    display: none !important;
  }