should getSupportedContraints be static?

[ShijunS]

If getSupportedContraints is "static" as in the current draft, all the examples need to be fixed.

For example,
var supports = navigator.mediaDevices.getSupportedConstraints("video");

should be changed to
var supports = MediaDevices.getSupportedConstraints("video");

[adam-be]

The static function is available on the instance navigator.mediaDevices as well. But we should probably remove the "static" keyword there since we have the singelton.

[dontcallmedom]

Agree we should remove the static keyword, it doesn't seem to gain us much here.

I haven't made a PR since the WebIDL in which this sits is broken, pending integration of jan-ivar/mediacapture-main@36d22bb in #37