chrome/browser/resources/settings/search_engines_page/search_engine_entry_css.html

<dom-module id="search-engine-entry">
  <template>
    <style>
      site-favicon {
        margin-inline-end: 8px;
      }

      .dropdown-content {
        background: white;
        box-shadow: 0 2px 6px grey;
      }
    </style>
  </template>
</dom-module>