Coread

This is a useful method for feature detection. Is it due to the lack of this/a mistake that Chrome returns displaySurface from getSupportedConstraints?

I think I was being confused by the naming here. getUserMedia takes an argument called "constraints" which is NOT the same as a the constraints returned from getSupportedConstraints. getDisplayMedia takes...

> Options like `selfBrowserSurface`, `systemAudio`, etc., affect the capture-session, not the track. One way to think of it is - would it ever make sense to `applyConstraints({...selfBrowserSurface: "exclude", ...})`. It...