Cast: Restructure RTCP interface to better fit our usage.

media/cast/rtcp/rtcp_receiver.h

Index: media/cast/rtcp/rtcp_receiver.h
diff --git a/media/cast/rtcp/rtcp_receiver.h b/media/cast/rtcp/rtcp_receiver.h
index 0d68d4705f0079cb32c0e263b0e854ca39c0c35d..bdb21a1a9b74d2a399a84be48ed6d39cb4b058bd 100644
--- a/media/cast/rtcp/rtcp_receiver.h
+++ b/media/cast/rtcp/rtcp_receiver.h
@@ -22,6 +22,12 @@ class RtcpReceiverFeedback {
 
   virtual void OnReceivedSendReportRequest() = 0;
 
+  virtual void OnReceivedReceiverLog(
+      const RtcpReceiverLogMessage& receiver_log) = 0;
+
+  virtual void OnReceivedSenderLog(
+      const RtcpSenderLogMessage& sender_log) = 0;
+
   virtual ~RtcpReceiverFeedback() {}
 };