| <!DOCType html> |
| <html> |
| <script src=event-timing-support.js></script> |
| <button id='button_child_frame' onclick='2'>Generate a 'click' event</button> |
| <img src=slow-image.py> |
| <script> |
| const clickTimeMin = performance.now(); |
| clickAndBlockMain('button_child_frame'); |
| const processingStartMin = performance.now(); |
| const observerPromise = new Promise((resolve, reject) => { |
| new PerformanceObserver((entryList) => { |
| resolve(entryList.getEntries()); |
| }).observe({ entryTypes: ['event'] }); |
| }); |
| window.addEventListener('load', e => { |
| observerPromise.then((observedEntries) => { |
| const onloadStart = performance.now(); |
| const bufferedEntries = performance.getEntriesByType('event'); |
| top.postMessage({ |
| "bufferedEntries" : bufferedEntries, |
| "observedEntries": observedEntries, |
| "clickTimeMin": clickTimeMin, |
| "processingStartMin" : processingStartMin, |
| "onloadStart" : onloadStart, |
| }, '*'); |
| }); |
| }); |
| </script> |
| </html> |