chromium/third_party/blink/web_tests/external/wpt/css/css-pseudo/file-selector-button-001.html

<!doctype html>
<title>::file-selector-button allows to customize the button in &lt;input type=file&gt;</title>
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/5049">
<link rel="mismatch" href="file-selector-button-001-notref.html">
<style>
  input::file-selector-button {
    background: green;
    color: white;
  }
</style>
<input type="file">