[webrtc-pc] Handling of invalid values in RTCRtpSender.setParameters()

Orphis has just created a new issue for https://github.com/w3c/webrtc-pc:

== Handling of invalid values in RTCRtpSender.setParameters() ==
Currently, a `RangeError` is reported when calling `setParameters()` with `scaleResolutionDownBy` set to a value lower than 1.0.
Shouldn't the same be done for other invalid values?

- `maxFramerate` is a double, which can be negative, very small or just 0. Huge values shouldn't be a problem.

- `maxBitrate` is an integer than can have be lower than some encoder dependent value. For Chrome's implementation, there is a 30000 bps minimum I believe.

- `ptime` can be bigger than `maxptime` defined in the SDP. This one is probably not a problem since it is only a preferred value and implementations just have to do their best.

- `scaleResolutionDownBy` can be a huge value. What happens if it forces frames to be smaller than what the encoder allows or it ends up with a fractional size smaller than 1x1?

Please view or discuss this issue at https://github.com/w3c/webrtc-pc/issues/1834 using your GitHub account