Delete deprecated rtc_event_log header

Bug: webrtc:10206
Change-Id: I9ed3148843c647372993729b87c0e74741ab540b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/147870
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28791}
diff --git a/rtc_tools/rtc_event_log_visualizer/analyzer.cc b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
index 2e66329..d2e6da2 100644
--- a/rtc_tools/rtc_event_log_visualizer/analyzer.cc
+++ b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
@@ -1218,7 +1218,7 @@
 
   SimulatedClock clock(0);
   BitrateObserver observer;
-  RtcEventLogNullImpl null_event_log;
+  RtcEventLogNull null_event_log;
   PacketRouter packet_router;
   PacedSender pacer(&clock, &packet_router, &null_event_log);
   TransportFeedbackAdapter transport_feedback;