Add a new overuse estimator for the delay based BWE behind experiment.

webrtc/modules/remote_bitrate_estimator/test/plot_dynamics.py

Index: webrtc/modules/remote_bitrate_estimator/test/plot_dynamics.py
diff --git a/webrtc/modules/remote_bitrate_estimator/test/plot_dynamics.py b/webrtc/modules/remote_bitrate_estimator/test/plot_dynamics.py
index dac47626debf72c3761db6ff53ee98cf11fd9d8b..5fdac51d09812a74729556f230598e2404bbebc1 100755
--- a/webrtc/modules/remote_bitrate_estimator/test/plot_dynamics.py
+++ b/webrtc/modules/remote_bitrate_estimator/test/plot_dynamics.py
@@ -140,8 +140,13 @@ def main():
   detector_state.addSubplot(['offset_ms'], "Time (s)", "Offset")
   detector_state.addSubplot(['gamma_ms'], "Time (s)", "Gamma")
 
+  trendline_state = Figure("TrendlineState")
+  trendline_state.addSubplot(["accumulated_delay_ms", "smoothed_delay_ms"],
+                             "Time (s)", "Delay (ms)")
+  trendline_state.addSubplot(["trendline_slope"], "Time (s)", "Slope")
+
   # Select which figures to plot here.
-  figures = [receiver, detector_state]
+  figures = [receiver, detector_state, trendline_state]
 
   # Add samples to the figures.
   for line in sys.stdin: