Use multimap to handle packets logged at the same time in the event log analyzer.

webrtc/tools/event_log_visualizer/analyzer.cc

Index: webrtc/tools/event_log_visualizer/analyzer.cc
diff --git a/webrtc/tools/event_log_visualizer/analyzer.cc b/webrtc/tools/event_log_visualizer/analyzer.cc
index 0d2483e24dcd082013037d3724774bb4c20c9670..1405908f8f1001f54900f4fcaf52515541370276 100644
--- a/webrtc/tools/event_log_visualizer/analyzer.cc
+++ b/webrtc/tools/event_log_visualizer/analyzer.cc
@@ -1013,8 +1013,8 @@ void EventLogAnalyzer::CreateStreamBitrateGraph(
 }
 
 void EventLogAnalyzer::CreateBweSimulationGraph(Plot* plot) {
-  std::map<uint64_t, const LoggedRtpPacket*> outgoing_rtp;
-  std::map<uint64_t, const LoggedRtcpPacket*> incoming_rtcp;
+  std::multimap<uint64_t, const LoggedRtpPacket*> outgoing_rtp;
+  std::multimap<uint64_t, const LoggedRtcpPacket*> incoming_rtcp;
 
   for (const auto& kv : rtp_packets_) {
     if (kv.first.GetDirection() == PacketDirection::kOutgoingPacket) {
@@ -1135,8 +1135,8 @@ void EventLogAnalyzer::CreateBweSimulationGraph(Plot* plot) {
 }
 
 void EventLogAnalyzer::CreateNetworkDelayFeedbackGraph(Plot* plot) {
-  std::map<uint64_t, const LoggedRtpPacket*> outgoing_rtp;
-  std::map<uint64_t, const LoggedRtcpPacket*> incoming_rtcp;
+  std::multimap<uint64_t, const LoggedRtpPacket*> outgoing_rtp;
+  std::multimap<uint64_t, const LoggedRtcpPacket*> incoming_rtcp;
 
   for (const auto& kv : rtp_packets_) {
     if (kv.first.GetDirection() == PacketDirection::kOutgoingPacket) {