--- a/dom/media/PeerConnection.js
+++ b/dom/media/PeerConnection.js
@@ -438,17 +438,16 @@ class RTCPeerConnection {
     }
 
     this.makeGetterSetterEH("ontrack");
     this.makeLegacyGetterSetterEH("onaddstream", "Use peerConnection.ontrack instead.");
     this.makeLegacyGetterSetterEH("onaddtrack", "Use peerConnection.ontrack instead.");
     this.makeGetterSetterEH("onicecandidate");
     this.makeGetterSetterEH("onnegotiationneeded");
     this.makeGetterSetterEH("onsignalingstatechange");
-    this.makeGetterSetterEH("onremovestream");
     this.makeGetterSetterEH("ondatachannel");
     this.makeGetterSetterEH("oniceconnectionstatechange");
     this.makeGetterSetterEH("onicegatheringstatechange");
     this.makeGetterSetterEH("onidentityresult");
     this.makeGetterSetterEH("onpeeridentity");
     this.makeGetterSetterEH("onidpassertionerror");
     this.makeGetterSetterEH("onidpvalidationerror");
 
@@ -1829,21 +1828,16 @@ class PeerConnectionObserver {
                               pc._onGetStatsIsLegacy);
     pc._onGetStatsSuccess(webidlobj);
   }
 
   onGetStatsError(code, message) {
     this._dompc._onGetStatsFailure(this.newError(message, code));
   }
 
-  onRemoveStream(stream) {
-    this.dispatchEvent(new this._dompc._win.MediaStreamEvent("removestream",
-                                                             { stream }));
-  }
-
   _getTransceiverWithRecvTrack(webrtcTrackId) {
     return this._dompc.getTransceivers().find(
         transceiver => transceiver.remoteTrackIdIs(webrtcTrackId));
   }
 
   onTransceiverNeeded(kind, transceiverImpl) {
     this._dompc._onTransceiverNeeded(kind, transceiverImpl);
   }

--- a/dom/webidl/PeerConnectionObserver.webidl
+++ b/dom/webidl/PeerConnectionObserver.webidl
@@ -29,19 +29,16 @@ interface PeerConnectionObserver
   void onGetStatsError(unsigned long name, DOMString message);
 
   /* Data channel callbacks */
   void notifyDataChannel(RTCDataChannel channel);
 
   /* Notification of one of several types of state changed */
   void onStateChange(PCObserverStateType state);
 
-  /* Changes to MediaStreamTracks */
-  void onRemoveStream(MediaStream stream);
-
   /* Transceiver management; called when setRemoteDescription causes a
      transceiver to be created on the C++ side */
   void onTransceiverNeeded(DOMString kind, TransceiverImpl transceiverImpl);
 
   /* DTMF callback */
   void onDTMFToneChange(MediaStreamTrack track, DOMString tone);
 
   /* Packet dump callback */