Added a new echo likelihood stat that reports the maximum value from a previous time period.

webrtc/api/statscollector.cc

Index: webrtc/api/statscollector.cc
diff --git a/webrtc/api/statscollector.cc b/webrtc/api/statscollector.cc
index fb6583ab91938b1876f5fd1f6c483a548bfb9923..8c143842736a008d88fb2a0778481a4df7ec59cc 100644
--- a/webrtc/api/statscollector.cc
+++ b/webrtc/api/statscollector.cc
@@ -104,7 +104,8 @@ void SetAudioProcessingStats(StatsReport* report,
                              int echo_delay_median_ms,
                              float aec_quality_min,
                              int echo_delay_std_ms,
-                             float residual_echo_likelihood) {
+                             float residual_echo_likelihood,
+                             float residual_echo_likelihood_recent_max) {
   report->AddBoolean(StatsReport::kStatsValueNameTypingNoiseState,
                      typing_noise_detected);
   if (aec_quality_min >= 0.0f) {
@@ -127,6 +128,9 @@ void SetAudioProcessingStats(StatsReport* report,
   if (residual_echo_likelihood >= 0.0f) {
     report->AddFloat(StatsReport::kStatsValueNameResidualEchoLikelihood,
                      residual_echo_likelihood);
+    report->AddFloat(

[hbos, 2017/01/16 11:29:49]

This can leak the default residual_echo_likelihood_recent_max -1 to the stats,
there should be an "if (residual_echo_likelihood_recent_max >= 0.0f)" or if the
two are tied together there should be a RTC_DCHECK_GE but that check would get
hit before Chrome's implementation is able to land.

[hbos, 2017/01/16 11:36:54]

If the stat is optional, prefer rtc::Optional to -1.

[hlundin-webrtc, 2017/01/16 13:44:56]

I'm making a minimal fix for now in https://codereview.webrtc.org/2632243002/.

+        StatsReport::kStatsValueNameResidualEchoLikelihoodRecentMax,
+        residual_echo_likelihood_recent_max);
   }
 }
 
@@ -187,7 +191,7 @@ void ExtractStats(const cricket::VoiceSenderInfo& info, StatsReport* report) {
       report, info.typing_noise_detected, info.echo_return_loss,
       info.echo_return_loss_enhancement, info.echo_delay_median_ms,
       info.aec_quality_min, info.echo_delay_std_ms,
-      info.residual_echo_likelihood);
+      info.residual_echo_likelihood, info.residual_echo_likelihood_recent_max);
 
   RTC_DCHECK_GE(info.audio_level, 0);
   const IntForAdd ints[] = {
@@ -940,7 +944,8 @@ void StatsCollector::UpdateReportFromAudioTrack(AudioTrackInterface* track,
         report, stats.typing_noise_detected, stats.echo_return_loss,
         stats.echo_return_loss_enhancement, stats.echo_delay_median_ms,
         stats.aec_quality_min, stats.echo_delay_std_ms,
-        stats.residual_echo_likelihood);
+        stats.residual_echo_likelihood,
+        stats.residual_echo_likelihood_recent_max);
 
     report->AddFloat(StatsReport::kStatsValueNameAecDivergentFilterFraction,
                      stats.aec_divergent_filter_fraction);