Add fraction loss in visualization tool.

Review-Url: https://codereview.webrtc.org/2204713005
Cr-Commit-Position: refs/heads/master@{#13644}
diff --git a/webrtc/tools/event_log_visualizer/generate_timeseries.cc b/webrtc/tools/event_log_visualizer/generate_timeseries.cc
index 273dcfa..27dc59c 100644
--- a/webrtc/tools/event_log_visualizer/generate_timeseries.cc
+++ b/webrtc/tools/event_log_visualizer/generate_timeseries.cc
@@ -51,6 +51,10 @@
             false,
             "Compute network delay based on sent packets and the received "
             "transport feedback.");
+DEFINE_bool(plot_fraction_loss,
+            false,
+            "Plot packet loss in percent for outgoing packets (as perceived by "
+            "the send-side bandwidth estimator).");
 
 int main(int argc, char* argv[]) {
   std::string program_name = argv[0];
@@ -116,6 +120,10 @@
     }
   }
 
+  if (FLAGS_plot_all || FLAGS_plot_fraction_loss) {
+    analyzer.CreateFractionLossGraph(collection->AppendNewPlot());
+  }
+
   if (FLAGS_plot_all || FLAGS_plot_total_bitrate) {
     if (FLAGS_incoming) {
       analyzer.CreateTotalBitrateGraph(webrtc::PacketDirection::kIncomingPacket,