Expose network thread in RTCPeerConnectionFactory+Private.

Change-Id: I98f352c832425da6c5500f579969025f258c7669
Bug: webrtc:15078
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/300843
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Auto-Submit: Peter Hanspers <peterhanspers@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39803}
diff --git a/sdk/objc/api/peerconnection/RTCPeerConnectionFactory+Private.h b/sdk/objc/api/peerconnection/RTCPeerConnectionFactory+Private.h
index 9613646..822585d 100644
--- a/sdk/objc/api/peerconnection/RTCPeerConnectionFactory+Private.h
+++ b/sdk/objc/api/peerconnection/RTCPeerConnectionFactory+Private.h
@@ -29,6 +29,7 @@
 
 @property(nonatomic, readonly) rtc::Thread* signalingThread;
 @property(nonatomic, readonly) rtc::Thread* workerThread;
+@property(nonatomic, readonly) rtc::Thread* networkThread;
 
 @end
 
diff --git a/sdk/objc/api/peerconnection/RTCPeerConnectionFactory.mm b/sdk/objc/api/peerconnection/RTCPeerConnectionFactory.mm
index c4d89e9..62b5554 100644
--- a/sdk/objc/api/peerconnection/RTCPeerConnectionFactory.mm
+++ b/sdk/objc/api/peerconnection/RTCPeerConnectionFactory.mm
@@ -339,4 +339,8 @@
   return _workerThread.get();
 }
 
+- (rtc::Thread *)networkThread {
+  return _networkThread.get();
+}
+
 @end