Overlay REMB in total bitrate graphs in visualization tool.

webrtc/tools/event_log_visualizer/plot_base.cc

Index: webrtc/tools/event_log_visualizer/plot_base.cc
diff --git a/webrtc/tools/event_log_visualizer/plot_base.cc b/webrtc/tools/event_log_visualizer/plot_base.cc
index 057a3108a4c7fc9f090837d29765b0bef58ecf2b..63fb09272e2423317bb98bcd3b0cfb443ebfc454 100644
--- a/webrtc/tools/event_log_visualizer/plot_base.cc
+++ b/webrtc/tools/event_log_visualizer/plot_base.cc
@@ -75,5 +75,11 @@ void Plot::AppendTimeSeries(TimeSeries&& time_series) {
   series_list_.emplace_back(std::move(time_series));
 }
 
+void Plot::AppendTimeSeriesIfNotEmpty(TimeSeries&& time_series) {
+  if (time_series.points.size() > 0) {
+    series_list_.emplace_back(std::move(time_series));
+  }
+}
+
 }  // namespace plotting
 }  // namespace webrtc