chromium/third_party/blink/web_tests/external/wpt/css/css-inline/text-box-trim/support/variant-class.js

'use strict';

/**
 * Add `class` search params to the `class` attribute of the root element.
 */
if (window.location.search) {
  const params = new URLSearchParams(window.location.search);
  if (params.has('class')) {
    const values = params.getAll('class')
                         .flatMap(value => value.split(','));
    document.documentElement.classList.add(...values);
  }
}