RTC[In/Out]boundRTPStreamStats.mediaTrackId collected.

webrtc/api/stats/rtcstats_objects.h

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 279 matching lines @@
   ~RTCRTPStreamStats() override;
 
   RTCStatsMember<std::string> ssrc;
   // TODO(hbos): When the remote case is supported |RTCStatsCollector| needs to
   // set this. crbug.com/657855, 657856
   RTCStatsMember<std::string> associate_stats_id;
   // TODO(hbos): Remote case not supported by |RTCStatsCollector|.
   // crbug.com/657855, 657856
   RTCStatsMember<bool> is_remote;  // = false
   RTCStatsMember<std::string> media_type;
-  // TODO(hbos): Not collected by |RTCStatsCollector|. crbug.com/657854, 659137
   RTCStatsMember<std::string> media_track_id;
   RTCStatsMember<std::string> transport_id;
   RTCStatsMember<std::string> codec_id;
   // FIR and PLI counts are only defined for |media_type == "video"|.
   RTCStatsMember<uint32_t> fir_count;
   RTCStatsMember<uint32_t> pli_count;
   // TODO(hbos): NACK count should be collected by |RTCStatsCollector| for both
   // audio and video but is only defined in the "video" case. crbug.com/657856
   RTCStatsMember<uint32_t> nack_count;
   // TODO(hbos): Not collected by |RTCStatsCollector|. crbug.com/657854
@@ skipping 85 matching lines @@
   RTCStatsMember<std::string> rtcp_transport_stats_id;
   RTCStatsMember<bool> active_connection;
   RTCStatsMember<std::string> selected_candidate_pair_id;
   RTCStatsMember<std::string> local_certificate_id;
   RTCStatsMember<std::string> remote_certificate_id;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_STATS_RTCSTATS_OBJECTS_H_