Revert of Refactor NACK bitrate allocation

webrtc/modules/rtp_rtcp/include/receive_statistics.h

Index: webrtc/modules/rtp_rtcp/include/receive_statistics.h
diff --git a/webrtc/modules/rtp_rtcp/include/receive_statistics.h b/webrtc/modules/rtp_rtcp/include/receive_statistics.h
index 90a848ad6335bd7584a67e013b2d7e7c7a7d820f..cc21e22df50f78fe7fda32f67bcc99857ce3e4bc 100644
--- a/webrtc/modules/rtp_rtcp/include/receive_statistics.h
+++ b/webrtc/modules/rtp_rtcp/include/receive_statistics.h
@@ -46,7 +46,7 @@
 
 typedef std::map<uint32_t, StreamStatistician*> StatisticianMap;
 
-class ReceiveStatistics {
+class ReceiveStatistics : public Module {
  public:
   virtual ~ReceiveStatistics() {}
 
@@ -89,6 +89,8 @@
                          size_t packet_length) override;
   StatisticianMap GetActiveStatisticians() const override;
   StreamStatistician* GetStatistician(uint32_t ssrc) const override;
+  int64_t TimeUntilNextProcess() override;
+  void Process() override;
   void SetMaxReorderingThreshold(int max_reordering_threshold) override;
   void RegisterRtcpStatisticsCallback(
       RtcpStatisticsCallback* callback) override;