// META: global=window 'use strict'; promise_test(async t => { assert_equals(typeof self.screen.isExtended, 'boolean'); }, 'screen.isExtended is present'); promise_test(async t => { let iframe = document.body.appendChild(document.createElement('iframe')); assert_equals(typeof iframe.contentWindow.screen.isExtended, 'boolean'); }, 'screen.isExtended is present for attached iframes');