Introduce RtpStreamReceiver and RtpStreamReceiverControllerInterface.

webrtc/call/flexfec_receive_stream_impl.h

Index: webrtc/call/flexfec_receive_stream_impl.h
diff --git a/webrtc/call/flexfec_receive_stream_impl.h b/webrtc/call/flexfec_receive_stream_impl.h
index e4c22942e62f3ce203fcc77b3813622bbc278229..a89940f8c3e52d9bb01e46eeea682f69aac882de 100644
--- a/webrtc/call/flexfec_receive_stream_impl.h
+++ b/webrtc/call/flexfec_receive_stream_impl.h
@@ -26,14 +26,18 @@ class RecoveredPacketReceiver;
 class RtcpRttStats;
 class RtpPacketReceived;
 class RtpRtcp;
+class RtpStreamReceiverControllerInterface;
+class RtpStreamReceiverInterface;
 
 class FlexfecReceiveStreamImpl : public FlexfecReceiveStream,
                                  public RtpPacketSinkInterface {
  public:
-  FlexfecReceiveStreamImpl(const Config& config,
-                           RecoveredPacketReceiver* recovered_packet_receiver,
-                           RtcpRttStats* rtt_stats,
-                           ProcessThread* process_thread);
+  FlexfecReceiveStreamImpl(
+      RtpStreamReceiverControllerInterface* receiver_controller,
+      const Config& config,
+      RecoveredPacketReceiver* recovered_packet_receiver,
+      RtcpRttStats* rtt_stats,
+      ProcessThread* process_thread);
   ~FlexfecReceiveStreamImpl() override;
 
   const Config& GetConfig() const { return config_; }
@@ -59,6 +63,8 @@ class FlexfecReceiveStreamImpl : public FlexfecReceiveStream,
   const std::unique_ptr<ReceiveStatistics> rtp_receive_statistics_;
   const std::unique_ptr<RtpRtcp> rtp_rtcp_;
   ProcessThread* process_thread_;
+
+  std::unique_ptr<RtpStreamReceiverInterface> rtp_stream_receiver_;
 };
 
 }  // namespace webrtc