Linux: DPI scaling on GNOME is handled incorrectly by the video element

[slackingway]

With display scaling set to 200% on GNOME 3.30.2 (resolution 3840x2160, up-to-date Arch Linux), the video is not scaled by 200% along with the rest of the UI.

There might be a workaround to this, but the fix could be simple to implement so I decided to report this before looking for one. I can try other desktop environments if needed.