--- a/dom/webidl/RTCPeerConnection.webidl
+++ b/dom/webidl/RTCPeerConnection.webidl
@@ -77,17 +77,21 @@ interface RTCPeerConnection : EventTarge
                             optional DOMString username);
   [Pref="media.peerconnection.identity.enabled"]
   Promise<DOMString> getIdentityAssertion();
   Promise<RTCSessionDescriptionInit> createOffer (optional RTCOfferOptions options);
   Promise<RTCSessionDescriptionInit> createAnswer (optional RTCAnswerOptions options);
   Promise<void> setLocalDescription (RTCSessionDescriptionInit description);
   Promise<void> setRemoteDescription (RTCSessionDescriptionInit description);
   readonly attribute RTCSessionDescription? localDescription;
+  readonly attribute RTCSessionDescription? currentLocalDescription;
+  readonly attribute RTCSessionDescription? pendingLocalDescription;
   readonly attribute RTCSessionDescription? remoteDescription;
+  readonly attribute RTCSessionDescription? currentRemoteDescription;
+  readonly attribute RTCSessionDescription? pendingRemoteDescription;
   readonly attribute RTCSignalingState signalingState;
   Promise<void> addIceCandidate ((RTCIceCandidateInit or RTCIceCandidate)? candidate);
   readonly attribute boolean? canTrickleIceCandidates;
   readonly attribute RTCIceGatheringState iceGatheringState;
   readonly attribute RTCIceConnectionState iceConnectionState;
   [Pref="media.peerconnection.identity.enabled"]
   readonly attribute Promise<RTCIdentityAssertion> peerIdentity;
   [Pref="media.peerconnection.identity.enabled"]