[webrtc-pc] Improve WPT testing of setParameters (#2729)

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

== Improve WPT testing of setParameters ==
[Create an RTCRtpSender](https://w3c.github.io/webrtc-pc/#dfn-create-an-rtcrtpsender) says: _"If sendEncodings is given as input to this algorithm, and is non-empty, set the [[[SendEncodings]]](https://w3c.github.io/webrtc-pc/#dfn-sendencodings) slot to sendEncodings. Otherwise, set it to a list containing a single [RTCRtpEncodingParameters](https://w3c.github.io/webrtc-pc/#dom-rtcrtpencodingparameters) with [active](https://w3c.github.io/webrtc-pc/#dom-rtcrtpencodingparameters-active) set to true."_

This says [[SendEncodings]] is never empty, but browsers [are returning](https://jsfiddle.net/jib1/e19zur8k/) `[]` from `sender.getParameters().encodings`.

Relevant [WPT tests are green](https://wpt.fyi/results/webrtc/RTCRtpParameters-encodings.html?label=experimental&label=master&aligned) because they [only check after negotiation](https://github.com/web-platform-tests/wpt/blob/master/webrtc/RTCRtpParameters-encodings.html#L78).

Please view or discuss this issue at https://github.com/w3c/webrtc-pc/issues/2729 using your GitHub account


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Received on Friday, 6 May 2022 22:37:43 UTC