Adding stats that can be used to compute output audio levels.

webrtc/stats/rtcstats_objects.cc

Index: webrtc/stats/rtcstats_objects.cc
diff --git a/webrtc/stats/rtcstats_objects.cc b/webrtc/stats/rtcstats_objects.cc
index 5397ef782cca502ff4508e2118b38a251c0b4af3..ef9b83f49dec6f0c74e9c29f5e8ae6365b4be235 100644
--- a/webrtc/stats/rtcstats_objects.cc
+++ b/webrtc/stats/rtcstats_objects.cc
@@ -373,8 +373,9 @@ RTCMediaStreamTrackStats::RTCMediaStreamTrackStats(
     : RTCMediaStreamTrackStats(std::string(id), timestamp_us, kind) {
 }
 
-RTCMediaStreamTrackStats::RTCMediaStreamTrackStats(
-    std::string&& id, int64_t timestamp_us, const char* kind)
+RTCMediaStreamTrackStats::RTCMediaStreamTrackStats(std::string&& id,
+                                                   int64_t timestamp_us,
+                                                   const char* kind)
     : RTCStats(std::move(id), timestamp_us),
       track_identifier("trackIdentifier"),
       remote_source("remoteSource"),
@@ -392,6 +393,8 @@ RTCMediaStreamTrackStats::RTCMediaStreamTrackStats(
       partial_frames_lost("partialFramesLost"),
       full_frames_lost("fullFramesLost"),
       audio_level("audioLevel"),
+      total_audio_energy("totalAudioEnergy"),
+      total_samples_duration("totalSamplesDuration"),
       echo_return_loss("echoReturnLoss"),
       echo_return_loss_enhancement("echoReturnLossEnhancement") {
   RTC_DCHECK(kind == RTCMediaStreamTrackKind::kAudio ||
@@ -417,9 +420,10 @@ RTCMediaStreamTrackStats::RTCMediaStreamTrackStats(
       partial_frames_lost(other.partial_frames_lost),
       full_frames_lost(other.full_frames_lost),
       audio_level(other.audio_level),
+      total_audio_energy(other.total_audio_energy),
+      total_samples_duration(other.total_samples_duration),
       echo_return_loss(other.echo_return_loss),
-      echo_return_loss_enhancement(other.echo_return_loss_enhancement) {
-}
+      echo_return_loss_enhancement(other.echo_return_loss_enhancement) {}
 
 RTCMediaStreamTrackStats::~RTCMediaStreamTrackStats() {
 }