Adds route changes in event logs.

Bug: webrtc:10614
Change-Id: Ifd859c977fc66cb606914ddb38a3fb3618e3ad90
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/135952
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27924}
diff --git a/call/rtp_transport_controller_send.h b/call/rtp_transport_controller_send.h
index 78617af..71608fe 100644
--- a/call/rtp_transport_controller_send.h
+++ b/call/rtp_transport_controller_send.h
@@ -129,6 +129,7 @@
   void UpdateControlState() RTC_RUN_ON(task_queue_);
 
   Clock* const clock_;
+  RtcEventLog* const event_log_;
   const FieldTrialBasedConfig trial_based_config_;
   PacketRouter packet_router_;
   std::vector<std::unique_ptr<RtpVideoSenderInterface>> video_rtp_senders_;