[webrtc-pc] new commits pushed by aboba

The following commits were just pushed by aboba to https://github.com/w3c/webrtc-pc:

* RTCDtlsTransport: Use internal slots
  by Adam Bergkvist
https://github.com/w3c/webrtc-pc/commit/95638a211c901ef57036d15a9151dabfcfb68f76

* Fix typo (review comment)
  by Adam Bergkvist
https://github.com/w3c/webrtc-pc/commit/c90de5c08bdd616932c2a0ba99fdaa2af02381af

* RTCDtlsTransport: Add text about generic state updates
  by Adam Bergkvist
https://github.com/w3c/webrtc-pc/commit/2aedb11cbe129ec3bad407791b394629967d2a20

* Merge pull request #1581 from w3c/dtls-transport-slots

RTCDtlsTransport: Use internal slots
  by Bernard Aboba
https://github.com/w3c/webrtc-pc/commit/ec11ce88d2f14a5257bb6f5f4ecb40d642f16a8c