chromium/third_party/blink/web_tests/fast/forms/select/select-percent-width-expected.html

<div style="width: 200px; display: inline-block">
    <select style="width: 100px">
        <option>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.</option>
    </select>
</div><div style="width: 200px; display: inline-block">
    <select style="width: 100px" multiple>
        <option>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.</option>
    </select>
</div>