Attach TransportFeedbackPacketLossTracker to ANA (PLR only)

webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h

Index: webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
diff --git a/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index 567fa0bc25539590d5a6b23c9a2d745b226f86be..b147125e567c8a0db663a0d948ad7da9e27cb93b 100644
--- a/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -304,7 +304,8 @@ class TransportFeedbackObserver {
 
   // Note: Transport-wide sequence number as sequence number. Arrival time
   // must be set to 0.
-  virtual void AddPacket(uint16_t sequence_number,
+  virtual void AddPacket(uint32_t ssrc,
+                         uint16_t sequence_number,
                          size_t length,
                          int probe_cluster_id) = 0;
 
@@ -313,6 +314,16 @@ class TransportFeedbackObserver {
   virtual std::vector<PacketInfo> GetTransportFeedbackVector() const = 0;
 };
 
+class TransportFeedbackAdapterObserver {

[minyue-webrtc, 2017/02/22 11:47:55]

Why cannot this be a TransportFeedbackObserver? See more detailed discussion on
this.

[elad.alon_webrtc.org, 2017/03/10 12:03:26]

(For posterity - some offline discussions were made, and this seems like the
best approach for now. A TODO in the code introduced in PS7 sheds some light on
the approach, though not on all of the reasons for it.)

+ public:
+  TransportFeedbackAdapterObserver() = default;

[minyue-webrtc, 2017/02/22 11:47:55]

no ctor needed

[elad.alon_webrtc.org, 2017/03/10 12:03:26]

Done.

+  virtual ~TransportFeedbackAdapterObserver() = default;
+
+  virtual void OnPacketAdded(uint32_t ssrc,
+                             uint16_t transport_sequence_number) = 0;
+  virtual void OnTransportFeedback(const rtcp::TransportFeedback& feedback) = 0;
+};
+
 class RtcpRttStats {
  public:
   virtual void OnRttUpdate(int64_t rtt) = 0;