Revert "Extracts ssrc based feedback tracking from feedback adapter."

This reverts commit 08c46adc1e9f9a8d74357fe132a68906ae6e6974.

Reason for revert: Incomplete.

Original change's description:
> Extracts ssrc based feedback tracking from feedback adapter.
> 
> This prepares for moving TransportFeedbackAdapter to TaskQueue.
> 
> Bug: webrtc:9883
> Change-Id: Ib333f6a6837ff6dd8b10813e8953e4d8cd5d8633
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/162040
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Commit-Queue: Sebastian Jansson <srte@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#30076}

TBR=sprang@webrtc.org,srte@webrtc.org

Change-Id: I6a79e7627f9de2d8c876d6a13ca36f3ac06fde7f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9883
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/162200
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30087}

7 files changed, 151 insertions, 232 deletions

diff --git a/modules/congestion_controller/rtp/BUILD.gn b/modules/congestion_controller/rtp/BUILD.gn
index 38a4bf19df..36a9b257bd 100644
--- a/modules/congestion_controller/rtp/BUILD.gn
+++ b/modules/congestion_controller/rtp/BUILD.gn
@@ -45,8 +45,6 @@ rtc_library("transport_feedback") {
   sources = [
     "transport_feedback_adapter.cc",
     "transport_feedback_adapter.h",
-    "transport_feedback_demuxer.cc",
-    "transport_feedback_demuxer.h",
   ]
 
   deps = [
@@ -71,7 +69,6 @@ if (rtc_include_tests) {
 
     sources = [
       "transport_feedback_adapter_unittest.cc",
-      "transport_feedback_demuxer_unittest.cc",
     ]
     deps = [
       ":transport_feedback",
diff --git a/modules/congestion_controller/rtp/transport_feedback_adapter.cc b/modules/congestion_controller/rtp/transport_feedback_adapter.cc
index 8783b737d9..b070b0e23a 100644
--- a/modules/congestion_controller/rtp/transport_feedback_adapter.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_adapter.cc
@@ -66,6 +66,30 @@ DataSize InFlightBytesTracker::GetOutstandingData(
 
 TransportFeedbackAdapter::TransportFeedbackAdapter() = default;
 
+TransportFeedbackAdapter::~TransportFeedbackAdapter() {
+  RTC_DCHECK(observers_.empty());
+}
+
+void TransportFeedbackAdapter::RegisterStreamFeedbackObserver(
+    std::vector<uint32_t> ssrcs,
+    StreamFeedbackObserver* observer) {
+  rtc::CritScope cs(&observers_lock_);
+  RTC_DCHECK(observer);
+  RTC_DCHECK(absl::c_find_if(observers_, [=](const auto& pair) {
+               return pair.second == observer;
+             }) == observers_.end());
+  observers_.push_back({ssrcs, observer});
+}
+
+void TransportFeedbackAdapter::DeRegisterStreamFeedbackObserver(
+    StreamFeedbackObserver* observer) {
+  rtc::CritScope cs(&observers_lock_);
+  RTC_DCHECK(observer);
+  const auto it = absl::c_find_if(
+      observers_, [=](const auto& pair) { return pair.second == observer; });
+  RTC_DCHECK(it != observers_.end());
+  observers_.erase(it);
+}
 
 void TransportFeedbackAdapter::AddPacket(const RtpPacketSendInfo& packet_info,
                                          size_t overhead_bytes,
@@ -80,6 +104,10 @@ void TransportFeedbackAdapter::AddPacket(const RtpPacketSendInfo& packet_info,
     packet.local_net_id = local_net_id_;
     packet.remote_net_id = remote_net_id_;
     packet.sent.pacing_info = packet_info.pacing_info;
+    if (packet_info.has_rtp_sequence_number) {
+      packet.ssrc = packet_info.ssrc;
+      packet.rtp_sequence_number = packet_info.rtp_sequence_number;
+    }
 
     while (!history_.empty() &&
            creation_time - history_.begin()->second.creation_time >
@@ -140,25 +168,32 @@ TransportFeedbackAdapter::ProcessTransportFeedback(
     RTC_LOG(LS_INFO) << "Empty transport feedback packet received.";
     return absl::nullopt;
   }
-
-  rtc::CritScope cs(&lock_);
+  std::vector<PacketFeedback> feedback_vector;
   TransportPacketsFeedback msg;
   msg.feedback_time = feedback_receive_time;
+  {
+    rtc::CritScope cs(&lock_);
+    msg.prior_in_flight =
+        in_flight_.GetOutstandingData(local_net_id_, remote_net_id_);
+    feedback_vector =
+        ProcessTransportFeedbackInner(feedback, feedback_receive_time);
+    if (feedback_vector.empty())
+      return absl::nullopt;
 
-  msg.prior_in_flight =
-      in_flight_.GetOutstandingData(local_net_id_, remote_net_id_);
-  msg.packet_feedbacks =
-      ProcessTransportFeedbackInner(feedback, feedback_receive_time);
-  if (msg.packet_feedbacks.empty())
-    return absl::nullopt;
-
-  auto it = history_.find(last_ack_seq_num_);
-  if (it != history_.end()) {
-    msg.first_unacked_send_time = it->second.sent.send_time;
+    for (const PacketFeedback& fb : feedback_vector) {
+      PacketResult res;
+      res.sent_packet = fb.sent;
+      res.receive_time = fb.receive_time;
+      msg.packet_feedbacks.push_back(res);
+    }
+    auto it = history_.find(last_ack_seq_num_);
+    if (it != history_.end()) {
+      msg.first_unacked_send_time = it->second.sent.send_time;
+    }
+    msg.data_in_flight =
+        in_flight_.GetOutstandingData(local_net_id_, remote_net_id_);
   }
-  msg.data_in_flight =
-      in_flight_.GetOutstandingData(local_net_id_, remote_net_id_);
-
+  SignalObservers(feedback_vector);
   return msg;
 }
 
@@ -174,7 +209,7 @@ DataSize TransportFeedbackAdapter::GetOutstandingData() const {
   return in_flight_.GetOutstandingData(local_net_id_, remote_net_id_);
 }
 
-std::vector<PacketResult>
+std::vector<PacketFeedback>
 TransportFeedbackAdapter::ProcessTransportFeedbackInner(
     const rtcp::TransportFeedback& feedback,
     Timestamp feedback_time) {
@@ -190,8 +225,8 @@ TransportFeedbackAdapter::ProcessTransportFeedbackInner(
   }
   last_timestamp_ = feedback.GetBaseTime();
 
-  std::vector<PacketResult> packet_result_vector;
-  packet_result_vector.reserve(feedback.GetPacketStatusCount());
+  std::vector<PacketFeedback> packet_feedback_vector;
+  packet_feedback_vector.reserve(feedback.GetPacketStatusCount());
 
   size_t failed_lookups = 0;
   size_t ignored = 0;
@@ -234,10 +269,7 @@ TransportFeedbackAdapter::ProcessTransportFeedbackInner(
     }
     if (packet_feedback.local_net_id == local_net_id_ &&
         packet_feedback.remote_net_id == remote_net_id_) {
-      PacketResult result;
-      result.sent_packet = packet_feedback.sent;
-      result.receive_time = packet_feedback.receive_time;
-      packet_result_vector.push_back(result);
+      packet_feedback_vector.push_back(packet_feedback);
     } else {
       ++ignored;
     }
@@ -253,7 +285,27 @@ TransportFeedbackAdapter::ProcessTransportFeedbackInner(
                      << " packets because they were sent on a different route.";
   }
 
-  return packet_result_vector;
+  return packet_feedback_vector;
+}
+
+void TransportFeedbackAdapter::SignalObservers(
+    const std::vector<PacketFeedback>& feedback_vector) {
+  rtc::CritScope cs(&observers_lock_);
+  for (auto& observer : observers_) {
+    std::vector<StreamFeedbackObserver::StreamPacketInfo> selected_feedback;
+    for (const auto& packet : feedback_vector) {
+      if (packet.ssrc && absl::c_count(observer.first, *packet.ssrc) > 0) {
+        StreamFeedbackObserver::StreamPacketInfo packet_info;
+        packet_info.ssrc = *packet.ssrc;
+        packet_info.rtp_sequence_number = packet.rtp_sequence_number;
+        packet_info.received = packet.receive_time.IsFinite();
+        selected_feedback.push_back(packet_info);
+      }
+    }
+    if (!selected_feedback.empty()) {
+      observer.second->OnPacketFeedbackVector(std::move(selected_feedback));
+    }
+  }
 }
 
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/transport_feedback_adapter.h b/modules/congestion_controller/rtp/transport_feedback_adapter.h
index b6bed96711..699c6ed489 100644
--- a/modules/congestion_controller/rtp/transport_feedback_adapter.h
+++ b/modules/congestion_controller/rtp/transport_feedback_adapter.h
@@ -38,6 +38,9 @@ struct PacketFeedback {
   // The network route ids that this packet is associated with.
   uint16_t local_net_id = 0;
   uint16_t remote_net_id = 0;
+  // The SSRC and RTP sequence number of the packet this feedback refers to.
+  absl::optional<uint32_t> ssrc;
+  uint16_t rtp_sequence_number = 0;
 };
 
 class InFlightBytesTracker {
@@ -52,9 +55,16 @@ class InFlightBytesTracker {
   std::map<RemoteAndLocalNetworkId, DataSize> in_flight_data_;
 };
 
-class TransportFeedbackAdapter {
+class TransportFeedbackAdapter : public StreamFeedbackProvider {
  public:
   TransportFeedbackAdapter();
+  virtual ~TransportFeedbackAdapter();
+
+  void RegisterStreamFeedbackObserver(
+      std::vector<uint32_t> ssrcs,
+      StreamFeedbackObserver* observer) override;
+  void DeRegisterStreamFeedbackObserver(
+      StreamFeedbackObserver* observer) override;
 
   void AddPacket(const RtpPacketSendInfo& packet_info,
                  size_t overhead_bytes,
@@ -73,10 +83,15 @@ class TransportFeedbackAdapter {
  private:
   enum class SendTimeHistoryStatus { kNotAdded, kOk, kDuplicate };
 
-  std::vector<PacketResult> ProcessTransportFeedbackInner(
+  void OnTransportFeedback(const rtcp::TransportFeedback& feedback);
+
+  std::vector<PacketFeedback> ProcessTransportFeedbackInner(
       const rtcp::TransportFeedback& feedback,
       Timestamp feedback_time) RTC_RUN_ON(&lock_);
 
+  void SignalObservers(
+      const std::vector<PacketFeedback>& packet_feedback_vector);
+
   rtc::CriticalSection lock_;
   DataSize pending_untracked_size_ RTC_GUARDED_BY(&lock_) = DataSize::Zero();
   Timestamp last_send_time_ RTC_GUARDED_BY(&lock_) = Timestamp::MinusInfinity();
@@ -95,6 +110,13 @@ class TransportFeedbackAdapter {
 
   uint16_t local_net_id_ RTC_GUARDED_BY(&lock_) = 0;
   uint16_t remote_net_id_ RTC_GUARDED_BY(&lock_) = 0;
+
+  rtc::CriticalSection observers_lock_;
+  // Maps a set of ssrcs to corresponding observer. Vectors are used rather than
+  // set/map to ensure that the processing order is consistent independently of
+  // the randomized ssrcs.
+  std::vector<std::pair<std::vector<uint32_t>, StreamFeedbackObserver*>>
+      observers_ RTC_GUARDED_BY(&observers_lock_);
 };
 
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc b/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
index a95f866630..e03bcc3750 100644
--- a/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
@@ -126,6 +126,58 @@ class TransportFeedbackAdapterTest : public ::testing::Test {
   std::unique_ptr<TransportFeedbackAdapter> adapter_;
 };
 
+TEST_F(TransportFeedbackAdapterTest, ObserverSanity) {
+  MockStreamFeedbackObserver mock;
+  adapter_->RegisterStreamFeedbackObserver({kSsrc}, &mock);
+
+  const std::vector<PacketResult> packets = {
+      CreatePacket(100, 200, 0, 1000, kPacingInfo0),
+      CreatePacket(110, 210, 1, 2000, kPacingInfo0),
+      CreatePacket(120, 220, 2, 3000, kPacingInfo0)};
+
+  rtcp::TransportFeedback feedback;
+  feedback.SetBase(packets[0].sent_packet.sequence_number,
+                   packets[0].receive_time.us());
+
+  for (const auto& packet : packets) {
+    OnSentPacket(packet);
+    EXPECT_TRUE(feedback.AddReceivedPacket(packet.sent_packet.sequence_number,
+                                           packet.receive_time.us()));
+  }
+
+  EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(1);
+  adapter_->ProcessTransportFeedback(feedback, clock_.CurrentTime());
+
+  adapter_->DeRegisterStreamFeedbackObserver(&mock);
+
+  auto new_packet = CreatePacket(130, 230, 3, 4000, kPacingInfo0);
+  OnSentPacket(new_packet);
+
+  rtcp::TransportFeedback second_feedback;
+  second_feedback.SetBase(new_packet.sent_packet.sequence_number,
+                          new_packet.receive_time.us());
+  EXPECT_TRUE(second_feedback.AddReceivedPacket(
+      new_packet.sent_packet.sequence_number, new_packet.receive_time.us()));
+  EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(0);
+  adapter_->ProcessTransportFeedback(second_feedback, clock_.CurrentTime());
+}
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+TEST_F(TransportFeedbackAdapterTest, ObserverDoubleRegistrationDeathTest) {
+  MockStreamFeedbackObserver mock;
+  adapter_->RegisterStreamFeedbackObserver({0}, &mock);
+  EXPECT_DEATH(adapter_->RegisterStreamFeedbackObserver({0}, &mock), "");
+  adapter_->DeRegisterStreamFeedbackObserver(&mock);
+}
+
+TEST_F(TransportFeedbackAdapterTest, ObserverMissingDeRegistrationDeathTest) {
+  MockStreamFeedbackObserver mock;
+  adapter_->RegisterStreamFeedbackObserver({0}, &mock);
+  EXPECT_DEATH(adapter_.reset(), "");
+  adapter_->DeRegisterStreamFeedbackObserver(&mock);
+}
+#endif
+
 TEST_F(TransportFeedbackAdapterTest, AdaptsFeedbackAndPopulatesSendTimes) {
   std::vector<PacketResult> packets;
   packets.push_back(CreatePacket(100, 200, 0, 1500, kPacingInfo0));
diff --git a/modules/congestion_controller/rtp/transport_feedback_demuxer.cc b/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
deleted file mode 100644
index c7893d71a9..0000000000
--- a/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- *  Copyright (c) 2019 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 "modules/congestion_controller/rtp/transport_feedback_demuxer.h"
-#include "absl/algorithm/container.h"
-#include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
-
-namespace webrtc {
-namespace {
-static const size_t kMaxPacketsInHistory = 5000;
-}
-void TransportFeedbackDemuxer::RegisterStreamFeedbackObserver(
-    std::vector<uint32_t> ssrcs,
-    StreamFeedbackObserver* observer) {
-  rtc::CritScope cs(&observers_lock_);
-  RTC_DCHECK(observer);
-  RTC_DCHECK(absl::c_find_if(observers_, [=](const auto& pair) {
-               return pair.second == observer;
-             }) == observers_.end());
-  observers_.push_back({ssrcs, observer});
-}
-
-void TransportFeedbackDemuxer::DeRegisterStreamFeedbackObserver(
-    StreamFeedbackObserver* observer) {
-  rtc::CritScope cs(&observers_lock_);
-  RTC_DCHECK(observer);
-  const auto it = absl::c_find_if(
-      observers_, [=](const auto& pair) { return pair.second == observer; });
-  RTC_DCHECK(it != observers_.end());
-  observers_.erase(it);
-}
-
-void TransportFeedbackDemuxer::AddPacket(const RtpPacketSendInfo& packet_info) {
-  rtc::CritScope cs(&lock_);
-  if (packet_info.has_rtp_sequence_number && packet_info.ssrc != 0) {
-    StreamFeedbackObserver::StreamPacketInfo info;
-    info.ssrc = packet_info.ssrc;
-    info.rtp_sequence_number = packet_info.rtp_sequence_number;
-    info.received = false;
-    history_.insert(
-        {seq_num_unwrapper_.Unwrap(packet_info.transport_sequence_number),
-         info});
-  }
-  while (history_.size() > kMaxPacketsInHistory) {
-    history_.erase(history_.begin());
-  }
-}
-
-void TransportFeedbackDemuxer::OnTransportFeedback(
-    const rtcp::TransportFeedback& feedback) {
-  std::vector<StreamFeedbackObserver::StreamPacketInfo> stream_feedbacks;
-  {
-    rtc::CritScope cs(&lock_);
-    for (const auto& packet : feedback.GetAllPackets()) {
-      int64_t seq_num =
-          seq_num_unwrapper_.UnwrapWithoutUpdate(packet.sequence_number());
-      auto it = history_.find(seq_num);
-      if (it != history_.end()) {
-        auto packet_info = it->second;
-        packet_info.received = packet.received();
-        stream_feedbacks.push_back(packet_info);
-        if (packet.received())
-          history_.erase(it);
-      }
-    }
-  }
-
-  rtc::CritScope cs(&observers_lock_);
-  for (auto& observer : observers_) {
-    std::vector<StreamFeedbackObserver::StreamPacketInfo> selected_feedback;
-    for (const auto& packet_info : stream_feedbacks) {
-      if (absl::c_count(observer.first, packet_info.ssrc) > 0) {
-        selected_feedback.push_back(packet_info);
-      }
-    }
-    if (!selected_feedback.empty()) {
-      observer.second->OnPacketFeedbackVector(std::move(selected_feedback));
-    }
-  }
-}
-
-}  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/transport_feedback_demuxer.h b/modules/congestion_controller/rtp/transport_feedback_demuxer.h
deleted file mode 100644
index bcd25d5835..0000000000
--- a/modules/congestion_controller/rtp/transport_feedback_demuxer.h
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- *  Copyright (c) 2019 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.
- */
-#ifndef MODULES_CONGESTION_CONTROLLER_RTP_TRANSPORT_FEEDBACK_DEMUXER_H_
-#define MODULES_CONGESTION_CONTROLLER_RTP_TRANSPORT_FEEDBACK_DEMUXER_H_
-
-#include <map>
-#include <utility>
-#include <vector>
-
-#include "modules/include/module_common_types_public.h"
-#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
-#include "rtc_base/critical_section.h"
-
-namespace webrtc {
-
-class TransportFeedbackDemuxer : public StreamFeedbackProvider {
- public:
-  // Implements StreamFeedbackProvider interface
-  void RegisterStreamFeedbackObserver(
-      std::vector<uint32_t> ssrcs,
-      StreamFeedbackObserver* observer) override;
-  void DeRegisterStreamFeedbackObserver(
-      StreamFeedbackObserver* observer) override;
-  void AddPacket(const RtpPacketSendInfo& packet_info);
-  void OnTransportFeedback(const rtcp::TransportFeedback& feedback);
-
- private:
-  rtc::CriticalSection lock_;
-  SequenceNumberUnwrapper seq_num_unwrapper_ RTC_GUARDED_BY(&lock_);
-  std::map<int64_t, StreamFeedbackObserver::StreamPacketInfo> history_
-      RTC_GUARDED_BY(&lock_);
-
-  // Maps a set of ssrcs to corresponding observer. Vectors are used rather than
-  // set/map to ensure that the processing order is consistent independently of
-  // the randomized ssrcs.
-  rtc::CriticalSection observers_lock_;
-  std::vector<std::pair<std::vector<uint32_t>, StreamFeedbackObserver*>>
-      observers_ RTC_GUARDED_BY(&observers_lock_);
-};
-}  // namespace webrtc
-
-#endif  // MODULES_CONGESTION_CONTROLLER_RTP_TRANSPORT_FEEDBACK_DEMUXER_H_
diff --git a/modules/congestion_controller/rtp/transport_feedback_demuxer_unittest.cc b/modules/congestion_controller/rtp/transport_feedback_demuxer_unittest.cc
deleted file mode 100644
index 144e3e135d..0000000000
--- a/modules/congestion_controller/rtp/transport_feedback_demuxer_unittest.cc
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- *  Copyright (c) 2019 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 "modules/congestion_controller/rtp/transport_feedback_demuxer.h"
-
-#include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
-#include "test/gmock.h"
-#include "test/gtest.h"
-
-namespace webrtc {
-namespace {
-
-using ::testing::_;
-static constexpr uint32_t kSsrc = 8492;
-
-class MockStreamFeedbackObserver : public webrtc::StreamFeedbackObserver {
- public:
-  MOCK_METHOD1(OnPacketFeedbackVector,
-               void(std::vector<StreamPacketInfo> packet_feedback_vector));
-};
-
-RtpPacketSendInfo CreatePacket(uint32_t ssrc,
-                               int16_t rtp_sequence_number,
-                               int64_t transport_sequence_number) {
-  RtpPacketSendInfo res;
-  res.ssrc = ssrc;
-  res.transport_sequence_number = transport_sequence_number;
-  res.rtp_sequence_number = rtp_sequence_number;
-  res.has_rtp_sequence_number = true;
-  return res;
-}
-}  // namespace
-TEST(TransportFeedbackDemuxerTest, ObserverSanity) {
-  TransportFeedbackDemuxer demuxer;
-  MockStreamFeedbackObserver mock;
-  demuxer.RegisterStreamFeedbackObserver({kSsrc}, &mock);
-
-  demuxer.AddPacket(CreatePacket(kSsrc, 55, 1));
-  demuxer.AddPacket(CreatePacket(kSsrc, 56, 2));
-  demuxer.AddPacket(CreatePacket(kSsrc, 57, 3));
-
-  rtcp::TransportFeedback feedback;
-  feedback.SetBase(1, 1000);
-  ASSERT_TRUE(feedback.AddReceivedPacket(1, 1000));
-  ASSERT_TRUE(feedback.AddReceivedPacket(2, 2000));
-  ASSERT_TRUE(feedback.AddReceivedPacket(3, 3000));
-
-  EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(1);
-  demuxer.OnTransportFeedback(feedback);
-
-  demuxer.DeRegisterStreamFeedbackObserver(&mock);
-
-  demuxer.AddPacket(CreatePacket(kSsrc, 58, 4));
-  rtcp::TransportFeedback second_feedback;
-  second_feedback.SetBase(4, 4000);
-  ASSERT_TRUE(second_feedback.AddReceivedPacket(4, 4000));
-
-  EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(0);
-  demuxer.OnTransportFeedback(second_feedback);
-}
-}  // namespace webrtc