RTCMediaStreamTrackStats.kind added and collected.

webrtc/api/stats/rtcstats_objects.h

Index: webrtc/api/stats/rtcstats_objects.h
diff --git a/webrtc/api/stats/rtcstats_objects.h b/webrtc/api/stats/rtcstats_objects.h
index a006b38ba0eb71cda023005f2f84c582ab96e3b3..acb6d242a52fce7068580b2a2c172b9fffa5b662 100644
--- a/webrtc/api/stats/rtcstats_objects.h
+++ b/webrtc/api/stats/rtcstats_objects.h
@@ -42,6 +42,14 @@ struct RTCIceCandidateType {
   static const char* kRelay;
 };
 
+// |RTCMediaStreamTrackStats::kind| is not an enum in the spec but the only
+// valid values are "audio" and "video".
+// https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamtrackstats-kind

[hbos, 2017/01/10 15:47:14]

URL from rawgit converted to github.io, but it hasn't merged yet so dead link...

[hta-webrtc, 2017/01/11 12:36:54]

It's merged, but a new dated version hasn't been published yet.

+struct RTCMediaStreamTrackKind {
+  static const char* kAudio;
+  static const char* kVideo;
+};
+
 // https://w3c.github.io/webrtc-stats/#certificatestats-dict*
 class RTCCertificateStats final : public RTCStats {
  public:
@@ -228,8 +236,10 @@ class RTCMediaStreamTrackStats final : public RTCStats {
  public:
   WEBRTC_RTCSTATS_DECL();
 
-  RTCMediaStreamTrackStats(const std::string& id, int64_t timestamp_us);
-  RTCMediaStreamTrackStats(std::string&& id, int64_t timestamp_us);
+  RTCMediaStreamTrackStats(const std::string& id, int64_t timestamp_us,
+                           const char* kind);
+  RTCMediaStreamTrackStats(std::string&& id, int64_t timestamp_us,
+                           const char* kind);
   RTCMediaStreamTrackStats(const RTCMediaStreamTrackStats& other);
   ~RTCMediaStreamTrackStats() override;
 
@@ -239,6 +249,8 @@ class RTCMediaStreamTrackStats final : public RTCStats {
   // TODO(hbos): |RTCStatsCollector| does not return stats for detached tracks.
   // crbug.com/659137
   RTCStatsMember<bool> detached;
+  // See |RTCMediaStreamTrackKind| for valid values.
+  RTCStatsMember<std::string> kind;
   // TODO(hbos): Not collected by |RTCStatsCollector|. crbug.com/659137
   RTCStatsMember<std::vector<std::string>> ssrc_ids;
   // Video-only members