Attach TransportFeedbackPacketLossTracker to ANA (PLR only)

webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h

 /*
  *  Copyright (c) 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.
  */
 
@@ skipping 319 matching lines @@
   uint16_t sequence_number;
   // Size of the packet excluding RTP headers.
   size_t payload_size;
   // The network route ids that this packet is associated with.
   uint16_t local_net_id;
   uint16_t remote_net_id;
   // Pacing information about this packet.
   PacedPacketInfo pacing_info;
 };
 
+// TODO(elad.alon): After the current TransportFeedbackObserver becomes obsolete
+// and is removed, use that name for this observer instead.
+// Background: The only implementers of this interface are
+// CongestionController and TransportFeedbackProxy.
+// CongestionController uses it to expose only a small subset of its
+// capabilities.
+// TransportFeedbackProxy is a temporary solution which exists to allow passing
+// the CongestionController down at a later stage.
+// Ideally, we'd get rid of this altogether, exposing CC. This will be done
+// after the order-of-creation issues have been resolved, and
+// TransportFeedbackProxy therefore removed. Then, we'll remove
+// TransportFeedbackAdapterObserver, reuse the name
+// TransportFeedbackObserver for TransportFeedbackAdapterObserver, and only
+// have one observer.
 class TransportFeedbackObserver {
  public:
   TransportFeedbackObserver() {}
   virtual ~TransportFeedbackObserver() {}
 
   // Note: Transport-wide sequence number as sequence number.
-  virtual void AddPacket(uint16_t sequence_number,
+  virtual void AddPacket(uint32_t ssrc,
+                         uint16_t sequence_number,
                          size_t length,
                          const PacedPacketInfo& pacing_info) = 0;
 
   virtual void OnTransportFeedback(const rtcp::TransportFeedback& feedback) = 0;
 
   virtual std::vector<PacketFeedback> GetTransportFeedbackVector() const = 0;
 };
 
+// See TODO above TransportFeedbackObserver for explanation of the difference
+// between these two.
+class TransportFeedbackAdapterObserver {
+ public:
+  virtual ~TransportFeedbackAdapterObserver() = default;
+
+  virtual void OnPacketAdded(uint32_t ssrc, uint16_t seq_num) = 0;
+  virtual void OnNewTransportFeedbacks(
+      const std::vector<PacketFeedback>& packet_feedbacks) = 0;
+};
+
 class RtcpRttStats {
  public:
   virtual void OnRttUpdate(int64_t rtt) = 0;
 
   virtual int64_t LastProcessedRtt() const = 0;
 
   virtual ~RtcpRttStats() {}
 };
 
 // Null object version of RtpFeedback.
@@ skipping 68 matching lines @@
 class TransportSequenceNumberAllocator {
  public:
   TransportSequenceNumberAllocator() {}
   virtual ~TransportSequenceNumberAllocator() {}
 
   virtual uint16_t AllocateSequenceNumber() = 0;
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_INCLUDE_RTP_RTCP_DEFINES_H_