Add plot of network delay change computed based on transport feedback.

webrtc/tools/event_log_visualizer/generate_timeseries.cc

Index: webrtc/tools/event_log_visualizer/generate_timeseries.cc
diff --git a/webrtc/tools/event_log_visualizer/generate_timeseries.cc b/webrtc/tools/event_log_visualizer/generate_timeseries.cc
index 20d369620b149c4344528d4968f8c9af78f20bca..273dcfa337224e6238d08731445e9d5b11911ea1 100644
--- a/webrtc/tools/event_log_visualizer/generate_timeseries.cc
+++ b/webrtc/tools/event_log_visualizer/generate_timeseries.cc
@@ -47,6 +47,10 @@ DEFINE_bool(plot_bwe,
             false,
             "Run the bandwidth estimator with the logged rtp and rtcp and plot "
             "the output.");
+DEFINE_bool(plot_network_delay_feedback,
+            false,
+            "Compute network delay based on sent packets and the received "
+            "transport feedback.");
 
 int main(int argc, char* argv[]) {
   std::string program_name = argv[0];
@@ -140,6 +144,10 @@ int main(int argc, char* argv[]) {
     analyzer.CreateBweGraph(collection->AppendNewPlot());
   }
 
+  if (FLAGS_plot_all || FLAGS_plot_network_delay_feedback) {
+    analyzer.CreateNetworkDelayFeebackGraph(collection->AppendNewPlot());
+  }
+
   collection->Draw();
 
   return 0;