Added graph for plotting the audio level from an Rtc event log.

webrtc/tools/event_log_visualizer/main.cc

Index: webrtc/tools/event_log_visualizer/main.cc
diff --git a/webrtc/tools/event_log_visualizer/main.cc b/webrtc/tools/event_log_visualizer/main.cc
index a3e931a281b6e00c1bd378d177656e898a329a46..bde172a835d5beeeb41436fac728d525a3490966 100644
--- a/webrtc/tools/event_log_visualizer/main.cc
+++ b/webrtc/tools/event_log_visualizer/main.cc
@@ -25,6 +25,9 @@ DEFINE_bool(plot_packets,
 DEFINE_bool(plot_audio_playout,
             false,
             "Plot bar graph showing the time between each audio playout.");
+DEFINE_bool(plot_audio_level,
+            false,
+            "Plot line graph showing the audio level.");
 DEFINE_bool(
     plot_sequence_number,
     false,
@@ -108,6 +111,10 @@ int main(int argc, char* argv[]) {
     analyzer.CreatePlayoutGraph(collection->AppendNewPlot());
   }
 
+  if (FLAGS_plot_all || FLAGS_plot_audio_level) {
+    analyzer.CreateAudioLevelGraph(collection->AppendNewPlot());
+  }
+
   if (FLAGS_plot_all || FLAGS_plot_sequence_number) {
     if (FLAGS_incoming) {
       analyzer.CreateSequenceNumberGraph(collection->AppendNewPlot());