Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1393 insertions, 0 deletions

diff --git a/third_party/libwebrtc/pc/legacy_stats_collector.cc b/third_party/libwebrtc/pc/legacy_stats_collector.cc
new file mode 100644
index 0000000000..6829e359b8
--- /dev/null
+++ b/third_party/libwebrtc/pc/legacy_stats_collector.cc
@@ -0,0 +1,1393 @@
+/*
+ *  Copyright 2012 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.
+ */
+
+#include "pc/legacy_stats_collector.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <algorithm>
+#include <cmath>
+#include <list>
+#include <set>
+#include <utility>
+#include <vector>
+
+#include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
+#include "api/audio_codecs/audio_encoder.h"
+#include "api/candidate.h"
+#include "api/data_channel_interface.h"
+#include "api/field_trials_view.h"
+#include "api/media_types.h"
+#include "api/rtp_sender_interface.h"
+#include "api/scoped_refptr.h"
+#include "api/sequence_checker.h"
+#include "api/video/video_content_type.h"
+#include "api/video/video_timing.h"
+#include "call/call.h"
+#include "media/base/media_channel.h"
+#include "media/base/media_channel_impl.h"
+#include "modules/audio_processing/include/audio_processing_statistics.h"
+#include "p2p/base/ice_transport_internal.h"
+#include "p2p/base/p2p_constants.h"
+#include "pc/channel.h"
+#include "pc/channel_interface.h"
+#include "pc/data_channel_utils.h"
+#include "pc/rtp_receiver.h"
+#include "pc/rtp_receiver_proxy.h"
+#include "pc/rtp_sender_proxy.h"
+#include "pc/rtp_transceiver.h"
+#include "pc/transport_stats.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/ip_address.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/rtc_certificate.h"
+#include "rtc_base/socket_address.h"
+#include "rtc_base/ssl_stream_adapter.h"
+#include "rtc_base/string_encode.h"
+#include "rtc_base/thread.h"
+#include "rtc_base/time_utils.h"
+#include "rtc_base/trace_event.h"
+
+namespace webrtc {
+namespace {
+
+// Field trial which controls whether to report standard-compliant bytes
+// sent/received per stream.  If enabled, padding and headers are not included
+// in bytes sent or received.
+constexpr char kUseStandardBytesStats[] = "WebRTC-UseStandardBytesStats";
+
+// The following is the enum RTCStatsIceCandidateType from
+// http://w3c.github.io/webrtc-stats/#rtcstatsicecandidatetype-enum such that
+// our stats report for ice candidate type could conform to that.
+const char STATSREPORT_LOCAL_PORT_TYPE[] = "host";
+const char STATSREPORT_STUN_PORT_TYPE[] = "serverreflexive";
+const char STATSREPORT_PRFLX_PORT_TYPE[] = "peerreflexive";
+const char STATSREPORT_RELAY_PORT_TYPE[] = "relayed";
+
+// Strings used by the stats collector to report adapter types. This fits the
+// general stype of http://w3c.github.io/webrtc-stats than what
+// AdapterTypeToString does.
+const char* STATSREPORT_ADAPTER_TYPE_ETHERNET = "lan";
+const char* STATSREPORT_ADAPTER_TYPE_WIFI = "wlan";
+const char* STATSREPORT_ADAPTER_TYPE_WWAN = "wwan";
+const char* STATSREPORT_ADAPTER_TYPE_VPN = "vpn";
+const char* STATSREPORT_ADAPTER_TYPE_LOOPBACK = "loopback";
+const char* STATSREPORT_ADAPTER_TYPE_WILDCARD = "wildcard";
+
+template <typename ValueType>
+struct TypeForAdd {
+  const StatsReport::StatsValueName name;
+  const ValueType& value;
+};
+
+typedef TypeForAdd<bool> BoolForAdd;
+typedef TypeForAdd<float> FloatForAdd;
+typedef TypeForAdd<int64_t> Int64ForAdd;
+typedef TypeForAdd<int> IntForAdd;
+
+StatsReport* AddTrackReport(StatsCollection* reports,
+                            const std::string& track_id) {
+  // Adds an empty track report.
+  StatsReport::Id id(
+      StatsReport::NewTypedId(StatsReport::kStatsReportTypeTrack, track_id));
+  StatsReport* report = reports->ReplaceOrAddNew(id);
+  report->AddString(StatsReport::kStatsValueNameTrackId, track_id);
+  return report;
+}
+
+template <class Track>
+void CreateTrackReport(const Track* track,
+                       StatsCollection* reports,
+                       TrackIdMap* track_ids) {
+  const std::string& track_id = track->id();
+  StatsReport* report = AddTrackReport(reports, track_id);
+  RTC_DCHECK(report != nullptr);
+  (*track_ids)[track_id] = report;
+}
+
+template <class TrackVector>
+void CreateTrackReports(const TrackVector& tracks,
+                        StatsCollection* reports,
+                        TrackIdMap* track_ids) {
+  for (const auto& track : tracks) {
+    CreateTrackReport(track.get(), reports, track_ids);
+  }
+}
+
+void ExtractCommonSendProperties(const cricket::MediaSenderInfo& info,
+                                 StatsReport* report,
+                                 bool use_standard_bytes_stats) {
+  report->AddString(StatsReport::kStatsValueNameCodecName, info.codec_name);
+  int64_t bytes_sent = info.payload_bytes_sent;
+  if (!use_standard_bytes_stats) {
+    bytes_sent += info.header_and_padding_bytes_sent;
+  }
+  report->AddInt64(StatsReport::kStatsValueNameBytesSent, bytes_sent);
+  if (info.rtt_ms >= 0) {
+    report->AddInt64(StatsReport::kStatsValueNameRtt, info.rtt_ms);
+  }
+}
+
+void ExtractCommonReceiveProperties(const cricket::MediaReceiverInfo& info,
+                                    StatsReport* report) {
+  report->AddString(StatsReport::kStatsValueNameCodecName, info.codec_name);
+}
+
+void SetAudioProcessingStats(StatsReport* report,
+                             const AudioProcessingStats& apm_stats) {
+  if (apm_stats.delay_median_ms) {
+    report->AddInt(StatsReport::kStatsValueNameEchoDelayMedian,
+                   *apm_stats.delay_median_ms);
+  }
+  if (apm_stats.delay_standard_deviation_ms) {
+    report->AddInt(StatsReport::kStatsValueNameEchoDelayStdDev,
+                   *apm_stats.delay_standard_deviation_ms);
+  }
+  if (apm_stats.echo_return_loss) {
+    report->AddInt(StatsReport::kStatsValueNameEchoReturnLoss,
+                   *apm_stats.echo_return_loss);
+  }
+  if (apm_stats.echo_return_loss_enhancement) {
+    report->AddInt(StatsReport::kStatsValueNameEchoReturnLossEnhancement,
+                   *apm_stats.echo_return_loss_enhancement);
+  }
+  if (apm_stats.residual_echo_likelihood) {
+    report->AddFloat(StatsReport::kStatsValueNameResidualEchoLikelihood,
+                     static_cast<float>(*apm_stats.residual_echo_likelihood));
+  }
+  if (apm_stats.residual_echo_likelihood_recent_max) {
+    report->AddFloat(
+        StatsReport::kStatsValueNameResidualEchoLikelihoodRecentMax,
+        static_cast<float>(*apm_stats.residual_echo_likelihood_recent_max));
+  }
+  if (apm_stats.divergent_filter_fraction) {
+    report->AddFloat(StatsReport::kStatsValueNameAecDivergentFilterFraction,
+                     static_cast<float>(*apm_stats.divergent_filter_fraction));
+  }
+}
+
+void ExtractStats(const cricket::VoiceReceiverInfo& info,
+                  StatsReport* report,
+                  bool use_standard_bytes_stats) {
+  ExtractCommonReceiveProperties(info, report);
+  const FloatForAdd floats[] = {
+      {StatsReport::kStatsValueNameExpandRate, info.expand_rate},
+      {StatsReport::kStatsValueNameSecondaryDecodedRate,
+       info.secondary_decoded_rate},
+      {StatsReport::kStatsValueNameSecondaryDiscardedRate,
+       info.secondary_discarded_rate},
+      {StatsReport::kStatsValueNameSpeechExpandRate, info.speech_expand_rate},
+      {StatsReport::kStatsValueNameAccelerateRate, info.accelerate_rate},
+      {StatsReport::kStatsValueNamePreemptiveExpandRate,
+       info.preemptive_expand_rate},
+      {StatsReport::kStatsValueNameTotalAudioEnergy, info.total_output_energy},
+      {StatsReport::kStatsValueNameTotalSamplesDuration,
+       info.total_output_duration}};
+
+  const IntForAdd ints[] = {
+      {StatsReport::kStatsValueNameCurrentDelayMs, info.delay_estimate_ms},
+      {StatsReport::kStatsValueNameDecodingCNG, info.decoding_cng},
+      {StatsReport::kStatsValueNameDecodingCTN, info.decoding_calls_to_neteq},
+      {StatsReport::kStatsValueNameDecodingCTSG,
+       info.decoding_calls_to_silence_generator},
+      {StatsReport::kStatsValueNameDecodingMutedOutput,
+       info.decoding_muted_output},
+      {StatsReport::kStatsValueNameDecodingNormal, info.decoding_normal},
+      {StatsReport::kStatsValueNameDecodingPLC, info.decoding_plc},
+      {StatsReport::kStatsValueNameDecodingPLCCNG, info.decoding_plc_cng},
+      {StatsReport::kStatsValueNameJitterBufferMs, info.jitter_buffer_ms},
+      {StatsReport::kStatsValueNameJitterReceived, info.jitter_ms},
+      {StatsReport::kStatsValueNamePacketsLost, info.packets_lost},
+      {StatsReport::kStatsValueNamePacketsReceived, info.packets_rcvd},
+      {StatsReport::kStatsValueNamePreferredJitterBufferMs,
+       info.jitter_buffer_preferred_ms},
+  };
+
+  for (const auto& f : floats)
+    report->AddFloat(f.name, f.value);
+
+  for (const auto& i : ints)
+    report->AddInt(i.name, i.value);
+  if (info.audio_level >= 0) {
+    report->AddInt(StatsReport::kStatsValueNameAudioOutputLevel,
+                   info.audio_level);
+  }
+  if (info.decoding_codec_plc)
+    report->AddInt(StatsReport::kStatsValueNameDecodingCodecPLC,
+                   info.decoding_codec_plc);
+
+  int64_t bytes_rcvd = info.payload_bytes_rcvd;
+  if (!use_standard_bytes_stats) {
+    bytes_rcvd += info.header_and_padding_bytes_rcvd;
+  }
+  report->AddInt64(StatsReport::kStatsValueNameBytesReceived, bytes_rcvd);
+  if (info.capture_start_ntp_time_ms >= 0) {
+    report->AddInt64(StatsReport::kStatsValueNameCaptureStartNtpTimeMs,
+                     info.capture_start_ntp_time_ms);
+  }
+  report->AddString(StatsReport::kStatsValueNameMediaType, "audio");
+}
+
+void ExtractStats(const cricket::VoiceSenderInfo& info,
+                  StatsReport* report,
+                  bool use_standard_bytes_stats) {
+  ExtractCommonSendProperties(info, report, use_standard_bytes_stats);
+
+  SetAudioProcessingStats(report, info.apm_statistics);
+
+  const FloatForAdd floats[] = {
+      {StatsReport::kStatsValueNameTotalAudioEnergy, info.total_input_energy},
+      {StatsReport::kStatsValueNameTotalSamplesDuration,
+       info.total_input_duration}};
+
+  RTC_DCHECK_GE(info.audio_level, 0);
+  const IntForAdd ints[] = {
+      {StatsReport::kStatsValueNameAudioInputLevel, info.audio_level},
+      {StatsReport::kStatsValueNameJitterReceived, info.jitter_ms},
+      {StatsReport::kStatsValueNamePacketsLost, info.packets_lost},
+      {StatsReport::kStatsValueNamePacketsSent, info.packets_sent},
+  };
+
+  for (const auto& f : floats) {
+    report->AddFloat(f.name, f.value);
+  }
+
+  for (const auto& i : ints) {
+    if (i.value >= 0) {
+      report->AddInt(i.name, i.value);
+    }
+  }
+  report->AddString(StatsReport::kStatsValueNameMediaType, "audio");
+  if (info.ana_statistics.bitrate_action_counter) {
+    report->AddInt(StatsReport::kStatsValueNameAnaBitrateActionCounter,
+                   *info.ana_statistics.bitrate_action_counter);
+  }
+  if (info.ana_statistics.channel_action_counter) {
+    report->AddInt(StatsReport::kStatsValueNameAnaChannelActionCounter,
+                   *info.ana_statistics.channel_action_counter);
+  }
+  if (info.ana_statistics.dtx_action_counter) {
+    report->AddInt(StatsReport::kStatsValueNameAnaDtxActionCounter,
+                   *info.ana_statistics.dtx_action_counter);
+  }
+  if (info.ana_statistics.fec_action_counter) {
+    report->AddInt(StatsReport::kStatsValueNameAnaFecActionCounter,
+                   *info.ana_statistics.fec_action_counter);
+  }
+  if (info.ana_statistics.frame_length_increase_counter) {
+    report->AddInt(StatsReport::kStatsValueNameAnaFrameLengthIncreaseCounter,
+                   *info.ana_statistics.frame_length_increase_counter);
+  }
+  if (info.ana_statistics.frame_length_decrease_counter) {
+    report->AddInt(StatsReport::kStatsValueNameAnaFrameLengthDecreaseCounter,
+                   *info.ana_statistics.frame_length_decrease_counter);
+  }
+  if (info.ana_statistics.uplink_packet_loss_fraction) {
+    report->AddFloat(StatsReport::kStatsValueNameAnaUplinkPacketLossFraction,
+                     *info.ana_statistics.uplink_packet_loss_fraction);
+  }
+}
+
+void ExtractStats(const cricket::VideoReceiverInfo& info,
+                  StatsReport* report,
+                  bool use_standard_bytes_stats) {
+  ExtractCommonReceiveProperties(info, report);
+  report->AddString(StatsReport::kStatsValueNameCodecImplementationName,
+                    info.decoder_implementation_name);
+  int64_t bytes_rcvd = info.payload_bytes_rcvd;
+  if (!use_standard_bytes_stats) {
+    bytes_rcvd += info.header_and_padding_bytes_rcvd;
+  }
+  report->AddInt64(StatsReport::kStatsValueNameBytesReceived, bytes_rcvd);
+  if (info.capture_start_ntp_time_ms >= 0) {
+    report->AddInt64(StatsReport::kStatsValueNameCaptureStartNtpTimeMs,
+                     info.capture_start_ntp_time_ms);
+  }
+  if (info.first_frame_received_to_decoded_ms >= 0) {
+    report->AddInt64(StatsReport::kStatsValueNameFirstFrameReceivedToDecodedMs,
+                     info.first_frame_received_to_decoded_ms);
+  }
+  if (info.qp_sum)
+    report->AddInt64(StatsReport::kStatsValueNameQpSum, *info.qp_sum);
+
+  if (info.nacks_sent) {
+    report->AddInt(StatsReport::kStatsValueNameNacksSent, *info.nacks_sent);
+  }
+
+  const IntForAdd ints[] = {
+      {StatsReport::kStatsValueNameCurrentDelayMs, info.current_delay_ms},
+      {StatsReport::kStatsValueNameDecodeMs, info.decode_ms},
+      {StatsReport::kStatsValueNameFirsSent, info.firs_sent},
+      {StatsReport::kStatsValueNameFrameHeightReceived, info.frame_height},
+      {StatsReport::kStatsValueNameFrameRateDecoded, info.framerate_decoded},
+      {StatsReport::kStatsValueNameFrameRateOutput, info.framerate_output},
+      {StatsReport::kStatsValueNameFrameRateReceived, info.framerate_rcvd},
+      {StatsReport::kStatsValueNameFrameWidthReceived, info.frame_width},
+      {StatsReport::kStatsValueNameJitterBufferMs, info.jitter_buffer_ms},
+      {StatsReport::kStatsValueNameMaxDecodeMs, info.max_decode_ms},
+      {StatsReport::kStatsValueNameMinPlayoutDelayMs,
+       info.min_playout_delay_ms},
+      {StatsReport::kStatsValueNamePacketsLost, info.packets_lost},
+      {StatsReport::kStatsValueNamePacketsReceived, info.packets_rcvd},
+      {StatsReport::kStatsValueNamePlisSent, info.plis_sent},
+      {StatsReport::kStatsValueNameRenderDelayMs, info.render_delay_ms},
+      {StatsReport::kStatsValueNameTargetDelayMs, info.target_delay_ms},
+      {StatsReport::kStatsValueNameFramesDecoded, info.frames_decoded},
+  };
+
+  for (const auto& i : ints)
+    report->AddInt(i.name, i.value);
+  report->AddString(StatsReport::kStatsValueNameMediaType, "video");
+
+  if (info.timing_frame_info) {
+    report->AddString(StatsReport::kStatsValueNameTimingFrameInfo,
+                      info.timing_frame_info->ToString());
+  }
+
+  report->AddInt64(StatsReport::kStatsValueNameInterframeDelayMaxMs,
+                   info.interframe_delay_max_ms);
+
+  report->AddString(
+      StatsReport::kStatsValueNameContentType,
+      webrtc::videocontenttypehelpers::ToString(info.content_type));
+}
+
+void ExtractStats(const cricket::VideoSenderInfo& info,
+                  StatsReport* report,
+                  bool use_standard_bytes_stats) {
+  ExtractCommonSendProperties(info, report, use_standard_bytes_stats);
+
+  report->AddString(StatsReport::kStatsValueNameCodecImplementationName,
+                    info.encoder_implementation_name);
+  report->AddBoolean(StatsReport::kStatsValueNameBandwidthLimitedResolution,
+                     (info.adapt_reason & 0x2) > 0);
+  report->AddBoolean(StatsReport::kStatsValueNameCpuLimitedResolution,
+                     (info.adapt_reason & 0x1) > 0);
+  report->AddBoolean(StatsReport::kStatsValueNameHasEnteredLowResolution,
+                     info.has_entered_low_resolution);
+
+  if (info.qp_sum)
+    report->AddInt(StatsReport::kStatsValueNameQpSum, *info.qp_sum);
+
+  const IntForAdd ints[] = {
+      {StatsReport::kStatsValueNameAdaptationChanges, info.adapt_changes},
+      {StatsReport::kStatsValueNameAvgEncodeMs, info.avg_encode_ms},
+      {StatsReport::kStatsValueNameEncodeUsagePercent,
+       info.encode_usage_percent},
+      {StatsReport::kStatsValueNameFirsReceived, info.firs_rcvd},
+      {StatsReport::kStatsValueNameFrameHeightSent, info.send_frame_height},
+      {StatsReport::kStatsValueNameFrameRateInput, round(info.framerate_input)},
+      {StatsReport::kStatsValueNameFrameRateSent, info.framerate_sent},
+      {StatsReport::kStatsValueNameFrameWidthSent, info.send_frame_width},
+      {StatsReport::kStatsValueNameNacksReceived, info.nacks_rcvd},
+      {StatsReport::kStatsValueNamePacketsLost, info.packets_lost},
+      {StatsReport::kStatsValueNamePacketsSent, info.packets_sent},
+      {StatsReport::kStatsValueNamePlisReceived, info.plis_rcvd},
+      {StatsReport::kStatsValueNameFramesEncoded, info.frames_encoded},
+      {StatsReport::kStatsValueNameHugeFramesSent, info.huge_frames_sent},
+  };
+
+  for (const auto& i : ints)
+    report->AddInt(i.name, i.value);
+  report->AddString(StatsReport::kStatsValueNameMediaType, "video");
+  report->AddString(
+      StatsReport::kStatsValueNameContentType,
+      webrtc::videocontenttypehelpers::ToString(info.content_type));
+}
+
+void ExtractStats(const cricket::BandwidthEstimationInfo& info,
+                  double stats_gathering_started,
+                  StatsReport* report) {
+  RTC_DCHECK(report->type() == StatsReport::kStatsReportTypeBwe);
+
+  report->set_timestamp(stats_gathering_started);
+  const IntForAdd ints[] = {
+      {StatsReport::kStatsValueNameAvailableSendBandwidth,
+       info.available_send_bandwidth},
+      {StatsReport::kStatsValueNameAvailableReceiveBandwidth,
+       info.available_recv_bandwidth},
+      {StatsReport::kStatsValueNameTargetEncBitrate, info.target_enc_bitrate},
+      {StatsReport::kStatsValueNameActualEncBitrate, info.actual_enc_bitrate},
+      {StatsReport::kStatsValueNameRetransmitBitrate, info.retransmit_bitrate},
+      {StatsReport::kStatsValueNameTransmitBitrate, info.transmit_bitrate},
+  };
+  for (const auto& i : ints)
+    report->AddInt(i.name, i.value);
+  report->AddInt64(StatsReport::kStatsValueNameBucketDelay, info.bucket_delay);
+}
+
+void ExtractRemoteStats(const cricket::MediaSenderInfo& info,
+                        StatsReport* report) {
+  report->set_timestamp(info.remote_stats[0].timestamp);
+  // TODO(hta): Extract some stats here.
+}
+
+void ExtractRemoteStats(const cricket::MediaReceiverInfo& info,
+                        StatsReport* report) {
+  report->set_timestamp(info.remote_stats[0].timestamp);
+  // TODO(hta): Extract some stats here.
+}
+
+std::string GetTrackIdBySsrc(
+    uint32_t ssrc,
+    StatsReport::Direction direction,
+    const std::map<uint32_t, std::string>& track_id_by_ssrc) {
+  auto it = track_id_by_ssrc.find(ssrc);
+  if (it != track_id_by_ssrc.end()) {
+    return it->second;
+  }
+  if (direction == StatsReport::kReceive) {
+    // If the track ID was not found, this might be an unsignaled receive
+    // SSRC, so try looking up by the special SSRC 0.
+    it = track_id_by_ssrc.find(0);
+    if (it != track_id_by_ssrc.end()) {
+      RTC_LOG(LS_INFO) << "Assuming SSRC=" << ssrc
+                       << " is an unsignalled receive stream corresponding "
+                          "to the RtpReceiver with track ID \""
+                       << it->second << "\".";
+      return it->second;
+    }
+  }
+  return "";
+}
+
+// Template to extract stats from a data vector.
+// In order to use the template, the functions that are called from it,
+// ExtractStats and ExtractRemoteStats, must be defined and overloaded
+// for each type.
+template <typename T>
+void ExtractStatsFromList(
+    const std::vector<T>& data,
+    const StatsReport::Id& transport_id,
+    LegacyStatsCollector* collector,
+    StatsReport::Direction direction,
+    const std::map<uint32_t, std::string>& track_id_by_ssrc) {
+  for (const auto& d : data) {
+    uint32_t ssrc = d.ssrc();
+    std::string track_id = GetTrackIdBySsrc(ssrc, direction, track_id_by_ssrc);
+    // Each track can have stats for both local and remote objects.
+    // TODO(hta): Handle the case of multiple SSRCs per object.
+    StatsReport* report =
+        collector->PrepareReport(true, ssrc, track_id, transport_id, direction);
+    if (report)
+      ExtractStats(d, report, collector->UseStandardBytesStats());
+
+    if (!d.remote_stats.empty()) {
+      report = collector->PrepareReport(false, ssrc, track_id, transport_id,
+                                        direction);
+      if (report)
+        ExtractRemoteStats(d, report);
+    }
+  }
+}
+
+}  // namespace
+
+const char* IceCandidateTypeToStatsType(const std::string& candidate_type) {
+  if (candidate_type == cricket::LOCAL_PORT_TYPE) {
+    return STATSREPORT_LOCAL_PORT_TYPE;
+  }
+  if (candidate_type == cricket::STUN_PORT_TYPE) {
+    return STATSREPORT_STUN_PORT_TYPE;
+  }
+  if (candidate_type == cricket::PRFLX_PORT_TYPE) {
+    return STATSREPORT_PRFLX_PORT_TYPE;
+  }
+  if (candidate_type == cricket::RELAY_PORT_TYPE) {
+    return STATSREPORT_RELAY_PORT_TYPE;
+  }
+  RTC_DCHECK_NOTREACHED();
+  return "unknown";
+}
+
+const char* AdapterTypeToStatsType(rtc::AdapterType type) {
+  switch (type) {
+    case rtc::ADAPTER_TYPE_UNKNOWN:
+      return "unknown";
+    case rtc::ADAPTER_TYPE_ETHERNET:
+      return STATSREPORT_ADAPTER_TYPE_ETHERNET;
+    case rtc::ADAPTER_TYPE_WIFI:
+      return STATSREPORT_ADAPTER_TYPE_WIFI;
+    case rtc::ADAPTER_TYPE_CELLULAR:
+    case rtc::ADAPTER_TYPE_CELLULAR_2G:
+    case rtc::ADAPTER_TYPE_CELLULAR_3G:
+    case rtc::ADAPTER_TYPE_CELLULAR_4G:
+    case rtc::ADAPTER_TYPE_CELLULAR_5G:
+      return STATSREPORT_ADAPTER_TYPE_WWAN;
+    case rtc::ADAPTER_TYPE_VPN:
+      return STATSREPORT_ADAPTER_TYPE_VPN;
+    case rtc::ADAPTER_TYPE_LOOPBACK:
+      return STATSREPORT_ADAPTER_TYPE_LOOPBACK;
+    case rtc::ADAPTER_TYPE_ANY:
+      return STATSREPORT_ADAPTER_TYPE_WILDCARD;
+    default:
+      RTC_DCHECK_NOTREACHED();
+      return "";
+  }
+}
+
+LegacyStatsCollector::LegacyStatsCollector(PeerConnectionInternal* pc)
+    : pc_(pc),
+      stats_gathering_started_(0),
+      use_standard_bytes_stats_(
+          pc->trials().IsEnabled(kUseStandardBytesStats)) {
+  RTC_DCHECK(pc_);
+}
+
+LegacyStatsCollector::~LegacyStatsCollector() {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+}
+
+// Wallclock time in ms.
+double LegacyStatsCollector::GetTimeNow() {
+  return static_cast<double>(rtc::TimeUTCMillis());
+}
+
+// Adds a MediaStream with tracks that can be used as a `selector` in a call
+// to GetStats.
+void LegacyStatsCollector::AddStream(MediaStreamInterface* stream) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  RTC_DCHECK(stream != NULL);
+
+  CreateTrackReports<AudioTrackVector>(stream->GetAudioTracks(), &reports_,
+                                       &track_ids_);
+  CreateTrackReports<VideoTrackVector>(stream->GetVideoTracks(), &reports_,
+                                       &track_ids_);
+}
+
+void LegacyStatsCollector::AddTrack(MediaStreamTrackInterface* track) {
+  if (track->kind() == MediaStreamTrackInterface::kAudioKind) {
+    CreateTrackReport(static_cast<AudioTrackInterface*>(track), &reports_,
+                      &track_ids_);
+  } else if (track->kind() == MediaStreamTrackInterface::kVideoKind) {
+    CreateTrackReport(static_cast<VideoTrackInterface*>(track), &reports_,
+                      &track_ids_);
+  } else {
+    RTC_DCHECK_NOTREACHED() << "Illegal track kind";
+  }
+}
+
+void LegacyStatsCollector::AddLocalAudioTrack(AudioTrackInterface* audio_track,
+                                              uint32_t ssrc) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  RTC_DCHECK(audio_track != NULL);
+#if RTC_DCHECK_IS_ON
+  for (const auto& track : local_audio_tracks_)
+    RTC_DCHECK(track.first != audio_track || track.second != ssrc);
+#endif
+
+  local_audio_tracks_.push_back(std::make_pair(audio_track, ssrc));
+
+  // Create the kStatsReportTypeTrack report for the new track if there is no
+  // report yet.
+  StatsReport::Id id(StatsReport::NewTypedId(StatsReport::kStatsReportTypeTrack,
+                                             audio_track->id()));
+  StatsReport* report = reports_.Find(id);
+  if (!report) {
+    report = reports_.InsertNew(id);
+    report->AddString(StatsReport::kStatsValueNameTrackId, audio_track->id());
+  }
+}
+
+void LegacyStatsCollector::RemoveLocalAudioTrack(
+    AudioTrackInterface* audio_track,
+    uint32_t ssrc) {
+  RTC_DCHECK(audio_track != NULL);
+  local_audio_tracks_.erase(
+      std::remove_if(
+          local_audio_tracks_.begin(), local_audio_tracks_.end(),
+          [audio_track, ssrc](const LocalAudioTrackVector::value_type& track) {
+            return track.first == audio_track && track.second == ssrc;
+          }),
+      local_audio_tracks_.end());
+}
+
+void LegacyStatsCollector::GetStats(MediaStreamTrackInterface* track,
+                                    StatsReports* reports) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  RTC_DCHECK(reports != NULL);
+  RTC_DCHECK(reports->empty());
+
+  rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+
+  if (!track) {
+    reports->reserve(reports_.size());
+    for (auto* r : reports_)
+      reports->push_back(r);
+    return;
+  }
+
+  StatsReport* report = reports_.Find(StatsReport::NewTypedId(
+      StatsReport::kStatsReportTypeSession, pc_->session_id()));
+  if (report)
+    reports->push_back(report);
+
+  report = reports_.Find(
+      StatsReport::NewTypedId(StatsReport::kStatsReportTypeTrack, track->id()));
+
+  if (!report)
+    return;
+
+  reports->push_back(report);
+
+  std::string track_id;
+  for (const auto* r : reports_) {
+    if (r->type() != StatsReport::kStatsReportTypeSsrc)
+      continue;
+
+    const StatsReport::Value* v =
+        r->FindValue(StatsReport::kStatsValueNameTrackId);
+    if (v && v->string_val() == track->id())
+      reports->push_back(r);
+  }
+}
+
+void LegacyStatsCollector::UpdateStats(
+    PeerConnectionInterface::StatsOutputLevel level) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  // Calls to UpdateStats() that occur less than kMinGatherStatsPeriodMs apart
+  // will be ignored. Using a monotonic clock specifically for this, while using
+  // a UTC clock for the reports themselves.
+  const int64_t kMinGatherStatsPeriodMs = 50;
+  int64_t cache_now_ms = rtc::TimeMillis();
+  if (cache_timestamp_ms_ != 0 &&
+      cache_timestamp_ms_ + kMinGatherStatsPeriodMs > cache_now_ms) {
+    return;
+  }
+  cache_timestamp_ms_ = cache_now_ms;
+  stats_gathering_started_ = GetTimeNow();
+
+  // TODO(tommi): ExtractSessionInfo now has a single hop to the network thread
+  // to fetch stats, then applies them on the signaling thread. See if we need
+  // to do this synchronously or if updating the stats without blocking is safe.
+  std::map<std::string, std::string> transport_names_by_mid =
+      ExtractSessionInfo();
+
+  // TODO(tommi): All of these hop over to the worker thread to fetch
+  // information.  We could post a task to run all of these and post
+  // the information back to the signaling thread where we can create and
+  // update stats reports.  That would also clean up the threading story a bit
+  // since we'd be creating/updating the stats report objects consistently on
+  // the same thread (this class has no locks right now).
+  ExtractBweInfo();
+  ExtractMediaInfo(transport_names_by_mid);
+  ExtractSenderInfo();
+  ExtractDataInfo();
+  UpdateTrackReports();
+}
+
+StatsReport* LegacyStatsCollector::PrepareReport(
+    bool local,
+    uint32_t ssrc,
+    const std::string& track_id,
+    const StatsReport::Id& transport_id,
+    StatsReport::Direction direction) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  StatsReport::Id id(StatsReport::NewIdWithDirection(
+      local ? StatsReport::kStatsReportTypeSsrc
+            : StatsReport::kStatsReportTypeRemoteSsrc,
+      rtc::ToString(ssrc), direction));
+  StatsReport* report = reports_.Find(id);
+  if (!report) {
+    report = reports_.InsertNew(id);
+  }
+
+  // FYI - for remote reports, the timestamp will be overwritten later.
+  report->set_timestamp(stats_gathering_started_);
+
+  report->AddInt64(StatsReport::kStatsValueNameSsrc, ssrc);
+  if (!track_id.empty()) {
+    report->AddString(StatsReport::kStatsValueNameTrackId, track_id);
+  }
+  // Add the mapping of SSRC to transport.
+  report->AddId(StatsReport::kStatsValueNameTransportId, transport_id);
+  return report;
+}
+
+StatsReport* LegacyStatsCollector::PrepareADMReport() {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  StatsReport::Id id(StatsReport::NewTypedId(
+      StatsReport::kStatsReportTypeSession, pc_->session_id()));
+  StatsReport* report = reports_.FindOrAddNew(id);
+  return report;
+}
+
+bool LegacyStatsCollector::IsValidTrack(const std::string& track_id) {
+  return reports_.Find(StatsReport::NewTypedId(
+             StatsReport::kStatsReportTypeTrack, track_id)) != nullptr;
+}
+
+StatsReport* LegacyStatsCollector::AddCertificateReports(
+    std::unique_ptr<rtc::SSLCertificateStats> cert_stats) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+
+  StatsReport* first_report = nullptr;
+  StatsReport* prev_report = nullptr;
+  for (rtc::SSLCertificateStats* stats = cert_stats.get(); stats;
+       stats = stats->issuer.get()) {
+    StatsReport::Id id(StatsReport::NewTypedId(
+        StatsReport::kStatsReportTypeCertificate, stats->fingerprint));
+
+    StatsReport* report = reports_.ReplaceOrAddNew(id);
+    report->set_timestamp(stats_gathering_started_);
+    report->AddString(StatsReport::kStatsValueNameFingerprint,
+                      stats->fingerprint);
+    report->AddString(StatsReport::kStatsValueNameFingerprintAlgorithm,
+                      stats->fingerprint_algorithm);
+    report->AddString(StatsReport::kStatsValueNameDer,
+                      stats->base64_certificate);
+    if (!first_report)
+      first_report = report;
+    else
+      prev_report->AddId(StatsReport::kStatsValueNameIssuerId, id);
+    prev_report = report;
+  }
+  return first_report;
+}
+
+StatsReport* LegacyStatsCollector::AddConnectionInfoReport(
+    const std::string& content_name,
+    int component,
+    int connection_id,
+    const StatsReport::Id& channel_report_id,
+    const cricket::ConnectionInfo& info) {
+  StatsReport::Id id(
+      StatsReport::NewCandidatePairId(content_name, component, connection_id));
+  StatsReport* report = reports_.ReplaceOrAddNew(id);
+  report->set_timestamp(stats_gathering_started_);
+
+  const BoolForAdd bools[] = {
+      {StatsReport::kStatsValueNameActiveConnection, info.best_connection},
+      {StatsReport::kStatsValueNameReceiving, info.receiving},
+      {StatsReport::kStatsValueNameWritable, info.writable},
+  };
+  for (const auto& b : bools)
+    report->AddBoolean(b.name, b.value);
+
+  report->AddId(StatsReport::kStatsValueNameChannelId, channel_report_id);
+  cricket::CandidateStats local_candidate_stats(info.local_candidate);
+  cricket::CandidateStats remote_candidate_stats(info.remote_candidate);
+  report->AddId(StatsReport::kStatsValueNameLocalCandidateId,
+                AddCandidateReport(local_candidate_stats, true)->id());
+  report->AddId(StatsReport::kStatsValueNameRemoteCandidateId,
+                AddCandidateReport(remote_candidate_stats, false)->id());
+
+  const Int64ForAdd int64s[] = {
+      {StatsReport::kStatsValueNameBytesReceived, info.recv_total_bytes},
+      {StatsReport::kStatsValueNameBytesSent, info.sent_total_bytes},
+      {StatsReport::kStatsValueNamePacketsSent, info.sent_total_packets},
+      {StatsReport::kStatsValueNameRtt, info.rtt},
+      {StatsReport::kStatsValueNameSendPacketsDiscarded,
+       info.sent_discarded_packets},
+      {StatsReport::kStatsValueNameSentPingRequestsTotal,
+       info.sent_ping_requests_total},
+      {StatsReport::kStatsValueNameSentPingRequestsBeforeFirstResponse,
+       info.sent_ping_requests_before_first_response},
+      {StatsReport::kStatsValueNameSentPingResponses, info.sent_ping_responses},
+      {StatsReport::kStatsValueNameRecvPingRequests, info.recv_ping_requests},
+      {StatsReport::kStatsValueNameRecvPingResponses, info.recv_ping_responses},
+  };
+  for (const auto& i : int64s)
+    report->AddInt64(i.name, i.value);
+
+  report->AddString(StatsReport::kStatsValueNameLocalAddress,
+                    info.local_candidate.address().ToString());
+  report->AddString(StatsReport::kStatsValueNameLocalCandidateType,
+                    info.local_candidate.type());
+  report->AddString(StatsReport::kStatsValueNameRemoteAddress,
+                    info.remote_candidate.address().ToString());
+  report->AddString(StatsReport::kStatsValueNameRemoteCandidateType,
+                    info.remote_candidate.type());
+  report->AddString(StatsReport::kStatsValueNameTransportType,
+                    info.local_candidate.protocol());
+  report->AddString(StatsReport::kStatsValueNameLocalCandidateRelayProtocol,
+                    info.local_candidate.relay_protocol());
+
+  return report;
+}
+
+StatsReport* LegacyStatsCollector::AddCandidateReport(
+    const cricket::CandidateStats& candidate_stats,
+    bool local) {
+  const auto& candidate = candidate_stats.candidate();
+  StatsReport::Id id(StatsReport::NewCandidateId(local, candidate.id()));
+  StatsReport* report = reports_.Find(id);
+  if (!report) {
+    report = reports_.InsertNew(id);
+    report->set_timestamp(stats_gathering_started_);
+    if (local) {
+      report->AddString(StatsReport::kStatsValueNameCandidateNetworkType,
+                        AdapterTypeToStatsType(candidate.network_type()));
+    }
+    report->AddString(StatsReport::kStatsValueNameCandidateIPAddress,
+                      candidate.address().ipaddr().ToString());
+    report->AddString(StatsReport::kStatsValueNameCandidatePortNumber,
+                      candidate.address().PortAsString());
+    report->AddInt(StatsReport::kStatsValueNameCandidatePriority,
+                   candidate.priority());
+    report->AddString(StatsReport::kStatsValueNameCandidateType,
+                      IceCandidateTypeToStatsType(candidate.type()));
+    report->AddString(StatsReport::kStatsValueNameCandidateTransportType,
+                      candidate.protocol());
+  }
+  report->set_timestamp(stats_gathering_started_);
+
+  if (local && candidate_stats.stun_stats().has_value()) {
+    const auto& stun_stats = candidate_stats.stun_stats().value();
+    report->AddInt64(StatsReport::kStatsValueNameSentStunKeepaliveRequests,
+                     stun_stats.stun_binding_requests_sent);
+    report->AddInt64(StatsReport::kStatsValueNameRecvStunKeepaliveResponses,
+                     stun_stats.stun_binding_responses_received);
+    report->AddFloat(StatsReport::kStatsValueNameStunKeepaliveRttTotal,
+                     stun_stats.stun_binding_rtt_ms_total);
+    report->AddFloat(StatsReport::kStatsValueNameStunKeepaliveRttSquaredTotal,
+                     stun_stats.stun_binding_rtt_ms_squared_total);
+  }
+
+  return report;
+}
+
+std::map<std::string, std::string> LegacyStatsCollector::ExtractSessionInfo() {
+  TRACE_EVENT0("webrtc", "LegacyStatsCollector::ExtractSessionInfo");
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+
+  SessionStats stats;
+  auto transceivers = pc_->GetTransceiversInternal();
+  pc_->network_thread()->BlockingCall(
+      [&, sctp_transport_name = pc_->sctp_transport_name(),
+       sctp_mid = pc_->sctp_mid()]() mutable {
+        stats = ExtractSessionInfo_n(
+            transceivers, std::move(sctp_transport_name), std::move(sctp_mid));
+      });
+
+  ExtractSessionInfo_s(stats);
+
+  return std::move(stats.transport_names_by_mid);
+}
+
+LegacyStatsCollector::SessionStats LegacyStatsCollector::ExtractSessionInfo_n(
+    const std::vector<rtc::scoped_refptr<
+        RtpTransceiverProxyWithInternal<RtpTransceiver>>>& transceivers,
+    absl::optional<std::string> sctp_transport_name,
+    absl::optional<std::string> sctp_mid) {
+  TRACE_EVENT0("webrtc", "LegacyStatsCollector::ExtractSessionInfo_n");
+  RTC_DCHECK_RUN_ON(pc_->network_thread());
+  rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+  SessionStats stats;
+  stats.candidate_stats = pc_->GetPooledCandidateStats();
+  for (auto& transceiver : transceivers) {
+    cricket::ChannelInterface* channel = transceiver->internal()->channel();
+    if (channel) {
+      stats.transport_names_by_mid[channel->mid()] =
+          std::string(channel->transport_name());
+    }
+  }
+
+  if (sctp_transport_name) {
+    RTC_DCHECK(sctp_mid);
+    stats.transport_names_by_mid[*sctp_mid] = *sctp_transport_name;
+  }
+
+  std::set<std::string> transport_names;
+  for (const auto& entry : stats.transport_names_by_mid) {
+    transport_names.insert(entry.second);
+  }
+
+  std::map<std::string, cricket::TransportStats> transport_stats_by_name =
+      pc_->GetTransportStatsByNames(transport_names);
+
+  for (auto& entry : transport_stats_by_name) {
+    stats.transport_stats.emplace_back(entry.first, std::move(entry.second));
+    TransportStats& transport = stats.transport_stats.back();
+
+    // Attempt to get a copy of the certificates from the transport and
+    // expose them in stats reports.  All channels in a transport share the
+    // same local and remote certificates.
+    //
+    StatsReport::Id local_cert_report_id, remote_cert_report_id;
+    rtc::scoped_refptr<rtc::RTCCertificate> certificate;
+    if (pc_->GetLocalCertificate(transport.name, &certificate)) {
+      transport.local_cert_stats =
+          certificate->GetSSLCertificateChain().GetStats();
+    }
+
+    std::unique_ptr<rtc::SSLCertChain> remote_cert_chain =
+        pc_->GetRemoteSSLCertChain(transport.name);
+    if (remote_cert_chain) {
+      transport.remote_cert_stats = remote_cert_chain->GetStats();
+    }
+  }
+
+  return stats;
+}
+
+void LegacyStatsCollector::ExtractSessionInfo_s(SessionStats& session_stats) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+
+  StatsReport::Id id(StatsReport::NewTypedId(
+      StatsReport::kStatsReportTypeSession, pc_->session_id()));
+  StatsReport* report = reports_.ReplaceOrAddNew(id);
+  report->set_timestamp(stats_gathering_started_);
+  report->AddBoolean(StatsReport::kStatsValueNameInitiator,
+                     pc_->initial_offerer());
+
+  for (const cricket::CandidateStats& stats : session_stats.candidate_stats) {
+    AddCandidateReport(stats, true);
+  }
+
+  for (auto& transport : session_stats.transport_stats) {
+    // Attempt to get a copy of the certificates from the transport and
+    // expose them in stats reports.  All channels in a transport share the
+    // same local and remote certificates.
+    //
+    StatsReport::Id local_cert_report_id, remote_cert_report_id;
+    if (transport.local_cert_stats) {
+      StatsReport* r =
+          AddCertificateReports(std::move(transport.local_cert_stats));
+      if (r)
+        local_cert_report_id = r->id();
+    }
+
+    if (transport.remote_cert_stats) {
+      StatsReport* r =
+          AddCertificateReports(std::move(transport.remote_cert_stats));
+      if (r)
+        remote_cert_report_id = r->id();
+    }
+
+    for (const auto& channel_iter : transport.stats.channel_stats) {
+      StatsReport::Id channel_stats_id(
+          StatsReport::NewComponentId(transport.name, channel_iter.component));
+      StatsReport* channel_report = reports_.ReplaceOrAddNew(channel_stats_id);
+      channel_report->set_timestamp(stats_gathering_started_);
+      channel_report->AddInt(StatsReport::kStatsValueNameComponent,
+                             channel_iter.component);
+      if (local_cert_report_id.get()) {
+        channel_report->AddId(StatsReport::kStatsValueNameLocalCertificateId,
+                              local_cert_report_id);
+      }
+      if (remote_cert_report_id.get()) {
+        channel_report->AddId(StatsReport::kStatsValueNameRemoteCertificateId,
+                              remote_cert_report_id);
+      }
+      int srtp_crypto_suite = channel_iter.srtp_crypto_suite;
+      if (srtp_crypto_suite != rtc::kSrtpInvalidCryptoSuite &&
+          rtc::SrtpCryptoSuiteToName(srtp_crypto_suite).length()) {
+        channel_report->AddString(
+            StatsReport::kStatsValueNameSrtpCipher,
+            rtc::SrtpCryptoSuiteToName(srtp_crypto_suite));
+      }
+      int ssl_cipher_suite = channel_iter.ssl_cipher_suite;
+      if (ssl_cipher_suite != rtc::kTlsNullWithNullNull &&
+          rtc::SSLStreamAdapter::SslCipherSuiteToName(ssl_cipher_suite)
+              .length()) {
+        channel_report->AddString(
+            StatsReport::kStatsValueNameDtlsCipher,
+            rtc::SSLStreamAdapter::SslCipherSuiteToName(ssl_cipher_suite));
+      }
+
+      // Collect stats for non-pooled candidates. Note that the reports
+      // generated here supersedes the candidate reports generated in
+      // AddConnectionInfoReport below, and they may report candidates that are
+      // not paired. Also, the candidate report generated in
+      // AddConnectionInfoReport do not report port stats like StunStats.
+      for (const cricket::CandidateStats& stats :
+           channel_iter.ice_transport_stats.candidate_stats_list) {
+        AddCandidateReport(stats, true);
+      }
+
+      int connection_id = 0;
+      for (const cricket::ConnectionInfo& info :
+           channel_iter.ice_transport_stats.connection_infos) {
+        StatsReport* connection_report = AddConnectionInfoReport(
+            transport.name, channel_iter.component, connection_id++,
+            channel_report->id(), info);
+        if (info.best_connection) {
+          channel_report->AddId(
+              StatsReport::kStatsValueNameSelectedCandidatePairId,
+              connection_report->id());
+        }
+      }
+    }
+  }
+}
+
+void LegacyStatsCollector::ExtractBweInfo() {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+
+  if (pc_->signaling_state() == PeerConnectionInterface::kClosed)
+    return;
+
+  webrtc::Call::Stats call_stats = pc_->GetCallStats();
+  cricket::BandwidthEstimationInfo bwe_info;
+  bwe_info.available_send_bandwidth = call_stats.send_bandwidth_bps;
+  bwe_info.available_recv_bandwidth = call_stats.recv_bandwidth_bps;
+  bwe_info.bucket_delay = call_stats.pacer_delay_ms;
+
+  // Fill in target encoder bitrate, actual encoder bitrate, rtx bitrate, etc.
+  // TODO(holmer): Also fill this in for audio.
+  auto transceivers = pc_->GetTransceiversInternal();
+  std::vector<cricket::VideoMediaSendChannelInterface*> video_media_channels;
+  for (const auto& transceiver : transceivers) {
+    if (transceiver->media_type() != cricket::MEDIA_TYPE_VIDEO) {
+      continue;
+    }
+    auto* video_channel = transceiver->internal()->channel();
+    if (video_channel) {
+      video_media_channels.push_back(video_channel->video_media_send_channel());
+    }
+  }
+
+  if (!video_media_channels.empty()) {
+    pc_->worker_thread()->BlockingCall([&] {
+      for (const auto& channel : video_media_channels) {
+        channel->FillBitrateInfo(&bwe_info);
+      }
+    });
+  }
+
+  StatsReport::Id report_id(StatsReport::NewBandwidthEstimationId());
+  StatsReport* report = reports_.FindOrAddNew(report_id);
+  ExtractStats(bwe_info, stats_gathering_started_, report);
+}
+
+namespace {
+
+class ChannelStatsGatherer {
+ public:
+  virtual ~ChannelStatsGatherer() = default;
+
+  virtual bool GetStatsOnWorkerThread() = 0;
+
+  virtual void ExtractStats(LegacyStatsCollector* collector) const = 0;
+
+  virtual bool HasRemoteAudio() const = 0;
+
+  std::string mid;
+  std::string transport_name;
+  std::map<uint32_t, std::string> sender_track_id_by_ssrc;
+  std::map<uint32_t, std::string> receiver_track_id_by_ssrc;
+
+ protected:
+  template <typename ReceiverT, typename SenderT>
+  void ExtractSenderReceiverStats(
+      LegacyStatsCollector* collector,
+      const std::vector<ReceiverT>& receiver_data,
+      const std::vector<SenderT>& sender_data) const {
+    RTC_DCHECK(collector);
+    StatsReport::Id transport_id = StatsReport::NewComponentId(
+        transport_name, cricket::ICE_CANDIDATE_COMPONENT_RTP);
+    ExtractStatsFromList(receiver_data, transport_id, collector,
+                         StatsReport::kReceive, receiver_track_id_by_ssrc);
+    ExtractStatsFromList(sender_data, transport_id, collector,
+                         StatsReport::kSend, sender_track_id_by_ssrc);
+  }
+};
+
+class VoiceChannelStatsGatherer final : public ChannelStatsGatherer {
+ public:
+  explicit VoiceChannelStatsGatherer(cricket::VoiceChannel* voice_channel)
+      : voice_channel_(voice_channel) {
+    RTC_DCHECK(voice_channel_);
+  }
+
+  bool GetStatsOnWorkerThread() override {
+    cricket::VoiceMediaSendInfo send_info;
+    cricket::VoiceMediaReceiveInfo receive_info;
+    bool success =
+        voice_channel_->voice_media_send_channel()->GetStats(&send_info);
+    success &= voice_channel_->voice_media_receive_channel()->GetStats(
+        &receive_info,
+        /*get_and_clear_legacy_stats=*/true);
+    if (success) {
+      voice_media_info = cricket::VoiceMediaInfo(std::move(send_info),
+                                                 std::move(receive_info));
+    }
+    return success;
+  }
+
+  void ExtractStats(LegacyStatsCollector* collector) const override {
+    ExtractSenderReceiverStats(collector, voice_media_info.receivers,
+                               voice_media_info.senders);
+    if (voice_media_info.device_underrun_count == -2 ||
+        voice_media_info.device_underrun_count > 0) {
+      StatsReport* report = collector->PrepareADMReport();
+      report->AddInt(StatsReport::kStatsValueNameAudioDeviceUnderrunCounter,
+                     voice_media_info.device_underrun_count);
+    }
+  }
+
+  bool HasRemoteAudio() const override {
+    return !voice_media_info.receivers.empty();
+  }
+
+ private:
+  cricket::VoiceChannel* voice_channel_;
+  cricket::VoiceMediaInfo voice_media_info;
+};
+
+class VideoChannelStatsGatherer final : public ChannelStatsGatherer {
+ public:
+  explicit VideoChannelStatsGatherer(cricket::VideoChannel* video_channel)
+      : video_channel_(video_channel) {
+    RTC_DCHECK(video_channel_);
+  }
+
+  bool GetStatsOnWorkerThread() override {
+    cricket::VideoMediaSendInfo send_info;
+    cricket::VideoMediaReceiveInfo receive_info;
+    bool success =
+        video_channel_->video_media_send_channel()->GetStats(&send_info);
+    success &=
+        video_channel_->video_media_receive_channel()->GetStats(&receive_info);
+    if (success) {
+      video_media_info = cricket::VideoMediaInfo(std::move(send_info),
+                                                 std::move(receive_info));
+    }
+    return success;
+  }
+
+  void ExtractStats(LegacyStatsCollector* collector) const override {
+    ExtractSenderReceiverStats(collector, video_media_info.receivers,
+                               video_media_info.aggregated_senders);
+  }
+
+  bool HasRemoteAudio() const override { return false; }
+
+ private:
+  cricket::VideoChannel* video_channel_;
+  cricket::VideoMediaInfo video_media_info;
+};
+
+std::unique_ptr<ChannelStatsGatherer> CreateChannelStatsGatherer(
+    cricket::ChannelInterface* channel) {
+  RTC_DCHECK(channel);
+  if (channel->media_type() == cricket::MEDIA_TYPE_AUDIO) {
+    return std::make_unique<VoiceChannelStatsGatherer>(
+        channel->AsVoiceChannel());
+  } else {
+    RTC_DCHECK_EQ(channel->media_type(), cricket::MEDIA_TYPE_VIDEO);
+    return std::make_unique<VideoChannelStatsGatherer>(
+        channel->AsVideoChannel());
+  }
+}
+
+}  // namespace
+
+void LegacyStatsCollector::ExtractMediaInfo(
+    const std::map<std::string, std::string>& transport_names_by_mid) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+
+  std::vector<std::unique_ptr<ChannelStatsGatherer>> gatherers;
+
+  auto transceivers = pc_->GetTransceiversInternal();
+  {
+    rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+    for (const auto& transceiver : transceivers) {
+      cricket::ChannelInterface* channel = transceiver->internal()->channel();
+      if (!channel) {
+        continue;
+      }
+      std::unique_ptr<ChannelStatsGatherer> gatherer =
+          CreateChannelStatsGatherer(channel);
+      gatherer->mid = channel->mid();
+      gatherer->transport_name = transport_names_by_mid.at(gatherer->mid);
+
+      for (const auto& sender : transceiver->internal()->senders()) {
+        auto track = sender->track();
+        std::string track_id = (track ? track->id() : "");
+        gatherer->sender_track_id_by_ssrc.insert(
+            std::make_pair(sender->ssrc(), track_id));
+      }
+
+      // Populating `receiver_track_id_by_ssrc` will be done on the worker
+      // thread as the `ssrc` property of the receiver needs to be accessed
+      // there.
+
+      gatherers.push_back(std::move(gatherer));
+    }
+  }
+
+  pc_->worker_thread()->BlockingCall([&] {
+    rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+    // Populate `receiver_track_id_by_ssrc` for the gatherers.
+    int i = 0;
+    for (const auto& transceiver : transceivers) {
+      cricket::ChannelInterface* channel = transceiver->internal()->channel();
+      if (!channel)
+        continue;
+      ChannelStatsGatherer* gatherer = gatherers[i++].get();
+      RTC_DCHECK_EQ(gatherer->mid, channel->mid());
+
+      for (const auto& receiver : transceiver->internal()->receivers()) {
+        gatherer->receiver_track_id_by_ssrc.insert(std::make_pair(
+            receiver->internal()->ssrc().value_or(0), receiver->track()->id()));
+      }
+    }
+
+    for (auto it = gatherers.begin(); it != gatherers.end();
+         /* incremented manually */) {
+      ChannelStatsGatherer* gatherer = it->get();
+      if (!gatherer->GetStatsOnWorkerThread()) {
+        RTC_LOG(LS_ERROR) << "Failed to get media channel stats for mid="
+                          << gatherer->mid;
+        it = gatherers.erase(it);
+        continue;
+      }
+      ++it;
+    }
+  });
+
+  rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+
+  bool has_remote_audio = false;
+  for (const auto& gatherer : gatherers) {
+    gatherer->ExtractStats(this);
+    has_remote_audio |= gatherer->HasRemoteAudio();
+  }
+
+  UpdateStatsFromExistingLocalAudioTracks(has_remote_audio);
+}
+
+void LegacyStatsCollector::ExtractSenderInfo() {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+
+  for (const auto& sender : pc_->GetSenders()) {
+    // TODO(bugs.webrtc.org/8694): SSRC == 0 currently means none. Delete check
+    // when that is fixed.
+    if (!sender->ssrc()) {
+      continue;
+    }
+    const rtc::scoped_refptr<MediaStreamTrackInterface> track(sender->track());
+    if (!track || track->kind() != MediaStreamTrackInterface::kVideoKind) {
+      continue;
+    }
+    // Safe, because kind() == kVideoKind implies a subclass of
+    // VideoTrackInterface; see mediastreaminterface.h.
+    VideoTrackSourceInterface* source =
+        static_cast<VideoTrackInterface*>(track.get())->GetSource();
+
+    VideoTrackSourceInterface::Stats stats;
+    if (!source->GetStats(&stats)) {
+      continue;
+    }
+    const StatsReport::Id stats_id = StatsReport::NewIdWithDirection(
+        StatsReport::kStatsReportTypeSsrc, rtc::ToString(sender->ssrc()),
+        StatsReport::kSend);
+    StatsReport* report = reports_.FindOrAddNew(stats_id);
+    report->AddInt(StatsReport::kStatsValueNameFrameWidthInput,
+                   stats.input_width);
+    report->AddInt(StatsReport::kStatsValueNameFrameHeightInput,
+                   stats.input_height);
+  }
+}
+
+void LegacyStatsCollector::ExtractDataInfo() {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+
+  rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+
+  std::vector<DataChannelStats> data_stats = pc_->GetDataChannelStats();
+  for (const auto& stats : data_stats) {
+    StatsReport::Id id(StatsReport::NewTypedIntId(
+        StatsReport::kStatsReportTypeDataChannel, stats.id));
+    StatsReport* report = reports_.ReplaceOrAddNew(id);
+    report->set_timestamp(stats_gathering_started_);
+    report->AddString(StatsReport::kStatsValueNameLabel, stats.label);
+    // Filter out the initial id (-1).
+    if (stats.id >= 0) {
+      report->AddInt(StatsReport::kStatsValueNameDataChannelId, stats.id);
+    }
+    report->AddString(StatsReport::kStatsValueNameProtocol, stats.protocol);
+    report->AddString(StatsReport::kStatsValueNameState,
+                      DataChannelInterface::DataStateString(stats.state));
+  }
+}
+
+StatsReport* LegacyStatsCollector::GetReport(const StatsReport::StatsType& type,
+                                             const std::string& id,
+                                             StatsReport::Direction direction) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  RTC_DCHECK(type == StatsReport::kStatsReportTypeSsrc ||
+             type == StatsReport::kStatsReportTypeRemoteSsrc);
+  return reports_.Find(StatsReport::NewIdWithDirection(type, id, direction));
+}
+
+void LegacyStatsCollector::UpdateStatsFromExistingLocalAudioTracks(
+    bool has_remote_tracks) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  // Loop through the existing local audio tracks.
+  for (const auto& it : local_audio_tracks_) {
+    AudioTrackInterface* track = it.first;
+    uint32_t ssrc = it.second;
+    StatsReport* report = GetReport(StatsReport::kStatsReportTypeSsrc,
+                                    rtc::ToString(ssrc), StatsReport::kSend);
+    if (report == NULL) {
+      // This can happen if a local audio track is added to a stream on the
+      // fly and the report has not been set up yet. Do nothing in this case.
+      RTC_LOG(LS_ERROR) << "Stats report does not exist for ssrc " << ssrc;
+      continue;
+    }
+
+    // The same ssrc can be used by both local and remote audio tracks.
+    const StatsReport::Value* v =
+        report->FindValue(StatsReport::kStatsValueNameTrackId);
+    if (!v || v->string_val() != track->id())
+      continue;
+
+    report->set_timestamp(stats_gathering_started_);
+    UpdateReportFromAudioTrack(track, report, has_remote_tracks);
+  }
+}
+
+void LegacyStatsCollector::UpdateReportFromAudioTrack(
+    AudioTrackInterface* track,
+    StatsReport* report,
+    bool has_remote_tracks) {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  RTC_DCHECK(track != NULL);
+
+  // Don't overwrite report values if they're not available.
+  int signal_level;
+  if (track->GetSignalLevel(&signal_level)) {
+    RTC_DCHECK_GE(signal_level, 0);
+    report->AddInt(StatsReport::kStatsValueNameAudioInputLevel, signal_level);
+  }
+
+  auto audio_processor(track->GetAudioProcessor());
+
+  if (audio_processor.get()) {
+    AudioProcessorInterface::AudioProcessorStatistics stats =
+        audio_processor->GetStats(has_remote_tracks);
+
+    SetAudioProcessingStats(report, stats.apm_statistics);
+  }
+}
+
+void LegacyStatsCollector::UpdateTrackReports() {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+
+  rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
+
+  for (const auto& entry : track_ids_) {
+    StatsReport* report = entry.second;
+    report->set_timestamp(stats_gathering_started_);
+  }
+}
+
+void LegacyStatsCollector::InvalidateCache() {
+  RTC_DCHECK_RUN_ON(pc_->signaling_thread());
+  cache_timestamp_ms_ = 0;
+}
+
+}  // namespace webrtc