Add video's to/from fullscreen transition/fading

in chromium based browsers, there is ugly transition to/from fullscreen, especially on youtube which is a bit funny in a way…

firefox has a smooth and slow fade which is nice

so you can make brave the first chromium to fix this, would be a fun little achievement imo
cheers

(similar thread exists, but is closed, was not well put by thread starter, this explains better)