chromium/third_party/blink/web_tests/fast/forms/select/option-relayout-modified-text.html

<!DOCTYPE html>
<script src="../../../resources/js-test.js"></script>
<p>Pass if the two selects below have the same width.</p>
<select id="ref">
    <option>OPTION TEXT</option>
</select>
<br>
<select id="test">
    <option></option>
</select>
<script>
description("Modifying text content of an option changes the width of the select.");

var refSelect = document.querySelector("#ref");
var testSelect = document.querySelector("#test");

shouldBeGreaterThan("refSelect.offsetWidth", "testSelect.offsetWidth");

testSelect.querySelector("option").textContent = "OPTION TEXT";

shouldBe("testSelect.offsetWidth", "refSelect.offsetWidth");
</script>