Refactor rtcp statistics: Rtcp module take narrow interface

webrtc/modules/rtp_rtcp/include/receive_statistics.h

 /*
  *  Copyright (c) 2013 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 WEBRTC_MODULES_RTP_RTCP_INCLUDE_RECEIVE_STATISTICS_H_
 #define WEBRTC_MODULES_RTP_RTCP_INCLUDE_RECEIVE_STATISTICS_H_
 
 #include <map>
+#include <vector>
 
 #include "webrtc/modules/include/module.h"
 #include "webrtc/modules/include/module_common_types.h"
+#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/report_block.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 class Clock;
 
+class ReceiveStatisticsReporter {
+ public:
+  // Fill in statistic fields of the rtcp report blocks for the active ssrcs.
+  // (i.e. everything except last_sr/delay_since_last_sr fields)
+  virtual std::vector<rtcp::ReportBlock> GetActiveStatistics() = 0;
+
+ protected:
+  ~ReceiveStatisticsReporter() = default;
+};
+
 class StreamStatistician {
  public:
   virtual ~StreamStatistician();
 
   virtual bool GetStatistics(RtcpStatistics* statistics, bool reset) = 0;
   virtual void GetDataCounters(size_t* bytes_received,
                                uint32_t* packets_received) const = 0;
 
   // Gets received stream data counters (includes reset counter values).
   virtual void GetReceiveStreamDataCounters(
       StreamDataCounters* data_counters) const = 0;
 
   virtual uint32_t BitrateReceived() const = 0;
 
   // Returns true if the packet with RTP header |header| is likely to be a
   // retransmitted packet, false otherwise.
   virtual bool IsRetransmitOfOldPacket(const RTPHeader& header,
                                        int64_t min_rtt) const = 0;
 
   // Returns true if |sequence_number| is received in order, false otherwise.
   virtual bool IsPacketInOrder(uint16_t sequence_number) const = 0;
 };
 
 typedef std::map<uint32_t, StreamStatistician*> StatisticianMap;
 
-class ReceiveStatistics {
+class ReceiveStatistics : public ReceiveStatisticsReporter {
  public:
   virtual ~ReceiveStatistics() {}
 
   static ReceiveStatistics* Create(Clock* clock);
 
   // Updates the receive statistics with this packet.
   virtual void IncomingPacket(const RTPHeader& rtp_header,
                               size_t packet_length,
                               bool retransmitted) = 0;
 
@@ skipping 11 matching lines @@
   // Sets the max reordering threshold in number of packets.
   virtual void SetMaxReorderingThreshold(int max_reordering_threshold) = 0;
 
   // Called on new RTCP stats creation.
   virtual void RegisterRtcpStatisticsCallback(
       RtcpStatisticsCallback* callback) = 0;
 
   // Called on new RTP stats creation.
   virtual void RegisterRtpStatisticsCallback(
       StreamDataCountersCallback* callback) = 0;
+
+  // TODO(danilchap): Remove other accessors and make this one pure virtual.
+  std::vector<rtcp::ReportBlock> GetActiveStatistics() override;
 };
 
 class NullReceiveStatistics : public ReceiveStatistics {
  public:
   void IncomingPacket(const RTPHeader& rtp_header,
                       size_t packet_length,
                       bool retransmitted) override;
   void FecPacketReceived(const RTPHeader& header,
                          size_t packet_length) override;
   StatisticianMap GetActiveStatisticians() const override;
   StreamStatistician* GetStatistician(uint32_t ssrc) const override;
   void SetMaxReorderingThreshold(int max_reordering_threshold) override;
   void RegisterRtcpStatisticsCallback(
       RtcpStatisticsCallback* callback) override;
   void RegisterRtpStatisticsCallback(
       StreamDataCountersCallback* callback) override;
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_INCLUDE_RECEIVE_STATISTICS_H_