Refactor composing report blocks for rtcp Sender/Receiver reports

webrtc/modules/rtp_rtcp/source/rtcp_sender.h

Index: webrtc/modules/rtp_rtcp/source/rtcp_sender.h
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_sender.h b/webrtc/modules/rtp_rtcp/source/rtcp_sender.h
index 9ab763ae40cdd30bce7be3e3f782fcbeada2a879..abf2da15749fc36fe85b5859d68e6c212f4b4688 100644
--- a/webrtc/modules/rtp_rtcp/source/rtcp_sender.h
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_sender.h
@@ -157,9 +157,8 @@ class RTCPSender {
   void PrepareReport(const FeedbackState& feedback_state)
       EXCLUSIVE_LOCKS_REQUIRED(critical_section_rtcp_sender_);
 
-  bool AddReportBlock(const FeedbackState& feedback_state,
-                      uint32_t ssrc,
-                      StreamStatistician* statistician)
+  std::vector<rtcp::ReportBlock> CreateReportBlocks(
+      const FeedbackState& feedback_state)
       EXCLUSIVE_LOCKS_REQUIRED(critical_section_rtcp_sender_);
 
   std::unique_ptr<rtcp::RtcpPacket> BuildSR(const RtcpContext& context)
@@ -214,8 +213,6 @@ class RTCPSender {
 
   ReceiveStatistics* receive_statistics_
       GUARDED_BY(critical_section_rtcp_sender_);
-  std::map<uint32_t, rtcp::ReportBlock> report_blocks_
-      GUARDED_BY(critical_section_rtcp_sender_);
   std::map<uint32_t, std::string> csrc_cnames_
       GUARDED_BY(critical_section_rtcp_sender_);