<!DOCTYPE HTML> <meta charset=utf-8> <title>Element Timing: observe text with display style.</title> <body> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <script src="resources/element-timing-helpers.js"></script> <style> h1 { display: flex; } h2 { display: grid; } h3 { display: block; } </style> <h1 id='title1' elementtiming='h1'>I am h1</h1> <h2 id='title2' elementtiming='h2'>I am h2</h2> <h3 id='title3' elementtiming='h3'>I am h3</h3> <script> async_test(function (t) { assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented"); const beforeRender = performance.now(); let observedFlex = false; let observedGrid = false; let observedBlock = false; const observer = new PerformanceObserver( t.step_func(function(entryList) { entryList.getEntries().forEach(entry => { if (entry.id === 'title1') { assert_false(observedFlex, 'Should observe flex once'); observedFlex = true; checkTextElement(entry, 'h1', 'title1', beforeRender, document.getElementById('title1')); } else if (entry.id === 'title2') { assert_false(observedGrid, 'Should observe grid once'); observedGrid = true; checkTextElement(entry, 'h2', 'title2', beforeRender, document.getElementById('title2')); } else { assert_equals(entry.id, 'title3', 'ID should be title1, title2, or title3'); assert_false(observedBlock, 'Should observe block once'); observedBlock = true; checkTextElement(entry, 'h3', 'title3', beforeRender, document.getElementById('title3')); } }); if (observedFlex && observedGrid && observedBlock) t.done(); }) ); observer.observe({type: 'element', buffered: true}); }, 'Text with display style is observable.'); </script> </body>