<!DOCTYPE HTML><metacharset=utf-8><title>LongTask Timing: long task in cross-origin sibling iframe</title><body><scriptsrc="/resources/testharness.js"></script><scriptsrc="/resources/testharnessreport.js"></script><scriptsrc="/common/get-host-info.sub.js"></script><script>constsibling_url=newURL("resources/subframe-with-longtask.html",newURL(location.pathname,get_host_info().HTTPS_REMOTE_ORIGIN)).href;async_test(t=>{assert_implements(window.PerformanceLongTaskTiming,'Longtasks are not supported.');window.addEventListener('message',t.step_func(e=>{assert_equals(e.data['entryType'],'longtask');assert_equals(e.data['frame-attribution'],'cross-origin-unreachable');assert_equals(e.data['task-attribution'],'unknown');assert_equals(e.data['containerType'],'window');assert_equals(e.data['containerId'],'');assert_equals(e.data['containerName'],'');assert_equals(e.data['containerSrc'],'');t.done();}));constobservingFrame=document.createElement('iframe');observingFrame.id='observing-iframe-id';observingFrame.name='observing-iframe-name';document.body.appendChild(observingFrame);observingFrame.src='resources/subframe-observing-longtask.html'observingFrame.onload=()=>{/* Create a cross-origin iframe that generates a long task. */constlongtaskFrame=document.createElement('iframe');longtaskFrame.id='longtask-iframe-id';longtaskFrame.name='longtask-iframe-name';document.body.appendChild(longtaskFrame);longtaskFrame.src=sibling_url;};},'Performance longtask entries from cross-origin iframe are observable in its sibling.');</script></body>
