Cleanup RtcpReceiver::TMMBRReceived function

BUG=webrtc:951

Review-Url: https://codereview.webrtc.org/2250633002
Cr-Commit-Position: refs/heads/master@{#13786}
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_receiver.h b/webrtc/modules/rtp_rtcp/source/rtcp_receiver.h
index f64baeb..f66df03 100644
--- a/webrtc/modules/rtp_rtcp/source/rtcp_receiver.h
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_receiver.h
@@ -92,9 +92,7 @@
     bool RtcpRrSequenceNumberTimeout(int64_t rtcp_interval_ms);
 
     // Get TMMBR
-    int32_t TMMBRReceived(uint32_t size,
-                          uint32_t accNumCandidates,
-                          TMMBRSet* candidateSet) const;
+    std::vector<rtcp::TmmbItem> TMMBRReceived() const;
 
     bool UpdateRTCPReceiveInformationTimers();