Fixed crash when PCF is destroyed before MediaSource/Track in ObjC

Bug: webrtc:9231
Change-Id: I31b86aa560f4ad230c9a94fedebebf320e0370a4
Reviewed-on: https://webrtc-review.googlesource.com/88221
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23981}
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCMediaStream.mm b/sdk/objc/Framework/Classes/PeerConnection/RTCMediaStream.mm
index 52f1771..c8bcfd9 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCMediaStream.mm
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCMediaStream.mm
@@ -109,14 +109,14 @@
     for (auto &track : audioTracks) {
       RTCMediaStreamTrackType type = RTCMediaStreamTrackTypeAudio;
       RTCAudioTrack *audioTrack =
-          [[RTCAudioTrack alloc] initWithNativeTrack:track type:type];
+          [[RTCAudioTrack alloc] initWithFactory:_factory nativeTrack:track type:type];
       [_audioTracks addObject:audioTrack];
     }
 
     for (auto &track : videoTracks) {
       RTCMediaStreamTrackType type = RTCMediaStreamTrackTypeVideo;
       RTCVideoTrack *videoTrack =
-          [[RTCVideoTrack alloc] initWithNativeTrack:track type:type];
+          [[RTCVideoTrack alloc] initWithFactory:_factory nativeTrack:track type:type];
       [_videoTracks addObject:videoTrack];
     }
   }