I'm not a javascript novice, so perhaps that's the issue but the following code eventually breaks because the PerformanceObserverCallback gets gc'd and m_callback.isEmpty() is true in PerformanceObserverCallback::call.

My code:

function perfCallback(list) { console.log('hello'); }
let observer = new PerformanceObserver(perfCallback);
observer.observe({entryTypes: ['resource']});


I have a site that sequentially loads 300 resources. After each it checks the timing before fetching the next. Sometimes it succeeds, but usually it gets stuck pretty quickly because the callback gets collected and the observer doesn't fire.

That should work right? My work-around is to make a top-level variable that references the function and pass that to the PerformanceObserver callback.