--- a/dom/media/PeerConnection.js
+++ b/dom/media/PeerConnection.js
@@ -1005,21 +1005,16 @@ RTCPeerConnection.prototype = {
       }));
     });
   },
 
   addStream: function(stream) {
     stream.getTracks().forEach(track => this.addTrack(track, stream));
   },
 
-  getStreamById: function(id) {
-    throw new this._win.DOMException("getStreamById not yet implemented",
-                                     "NotSupportedError");
-  },
-
   addTrack: function(track, stream) {
     if (stream.currentTime === undefined) {
       throw new this._win.DOMException("invalid stream.", "InvalidParameterError");
     }
     this._checkClosed();
     this._senders.forEach(sender => {
       if (sender.track == track) {
         throw new this._win.DOMException("already added.",

--- a/dom/webidl/RTCPeerConnection.webidl
+++ b/dom/webidl/RTCPeerConnection.webidl
@@ -115,18 +115,16 @@ interface RTCPeerConnection : EventTarge
   [ChromeOnly]
   attribute DOMString id;
 
   RTCConfiguration      getConfiguration ();
   [UnsafeInPrerendering, Deprecated="RTCPeerConnectionGetStreams"]
   sequence<MediaStream> getLocalStreams ();
   [UnsafeInPrerendering, Deprecated="RTCPeerConnectionGetStreams"]
   sequence<MediaStream> getRemoteStreams ();
-  [UnsafeInPrerendering]
-  MediaStream? getStreamById (DOMString streamId);
   void addStream (MediaStream stream);
 
   // replaces addStream; fails if already added
   // because a track can be part of multiple streams, stream parameters
   // indicate which particular streams should be referenced in signaling
 
   RTCRtpSender addTrack(MediaStreamTrack track,
                         MediaStream stream,