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

webrtc/api/statscollector_unittest.cc

Index: webrtc/api/statscollector_unittest.cc
diff --git a/webrtc/api/statscollector_unittest.cc b/webrtc/api/statscollector_unittest.cc
index 50ae51d6b0b9b8b0b375f35119a680f07f848957..1e2944cfa803734e4269a0939cf4b97283045c24 100644
--- a/webrtc/api/statscollector_unittest.cc
+++ b/webrtc/api/statscollector_unittest.cc
@@ -414,6 +414,11 @@ void VerifyVoiceSenderInfoReport(const StatsReport* report,
                        &value_in_report));
   EXPECT_EQ(rtc::ToString<float>(sinfo.residual_echo_likelihood),
             value_in_report);
+  EXPECT_TRUE(GetValue(
+      report, StatsReport::kStatsValueNameResidualEchoLikelihoodRecentMax,
+      &value_in_report));
+  EXPECT_EQ(rtc::ToString<float>(sinfo.residual_echo_likelihood_recent_max),
+            value_in_report);
   EXPECT_TRUE(GetValue(report, StatsReport::kStatsValueNameAudioInputLevel,
                        &value_in_report));
   EXPECT_EQ(rtc::ToString<int>(sinfo.audio_level), value_in_report);