EventLogVisualizer pacer delay plot fix.

Bug: none
Change-Id: I86bcad68e522b2a18937cc92c051d3d0feb46a07
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/159960
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29828}
diff --git a/rtc_tools/rtc_event_log_visualizer/analyzer.cc b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
index 1ab7eb9..8d889f7 100644
--- a/rtc_tools/rtc_event_log_visualizer/analyzer.cc
+++ b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
@@ -1459,7 +1459,9 @@
       GetNetworkTrace(parsed_log_);
   absl::c_stable_sort(matched_rtp_rtcp, [](const MatchedSendArrivalTimes& a,
                                            const MatchedSendArrivalTimes& b) {
-    return a.feedback_arrival_time_ms < b.feedback_arrival_time_ms;
+    return a.feedback_arrival_time_ms < b.feedback_arrival_time_ms ||
+           (a.feedback_arrival_time_ms == b.feedback_arrival_time_ms &&
+            a.arrival_time_ms < b.arrival_time_ms);
   });
   for (const auto& packet : matched_rtp_rtcp) {
     if (packet.arrival_time_ms == MatchedSendArrivalTimes::kNotReceived)