Detached HTMLVideoElements leaks when used with react

[Herman Bilous]

Steps to reproduce:

1. Modify examples/nextjs-with-typescript/pages/index.tsx by adding a button that mounts and unmounts e.g:

const [mounted, setMounted] = useState(false);
return (
....
      <button onClick={() => setMounted(prev => !prev)}>
          {mounted ? "Unmount": "Mount"}
      </button>
      {mounted && (<MediaController />)}
....

2. Run example and open it in chrome.
3. Click on button a few times to mount and unmount controller
4. Create memory snapshot with devtools memory tab. Search for "video" in class filter

Actual result:
Observe a list that looks like this

Note: number of Detached HTMLVideoElements will be equal to number of times "unmount" is clicked + 1.

Expected result:
Only one Detached HTMLVideoElement is present in snapshots. Clicking on button won't change the number of Detached HTMLVideoElements.

[Wesley Luyten]

thanks for reporting this! we will investigate

[Dylan Jhaveri]

Double thank you @HermanBilous for the easy to repro report of this memory leak