cast: Split Rtcp into two for sender and receiver

media/cast/net/rtcp/rtcp_utility.h

Index: media/cast/net/rtcp/rtcp_utility.h
diff --git a/media/cast/net/rtcp/rtcp_utility.h b/media/cast/net/rtcp/rtcp_utility.h
index 8850b94b0c8e37962ea6d3aeabb8ee89ec952817..e16cc378b6f71e0b6c58c7810484661aad0900bf 100644
--- a/media/cast/net/rtcp/rtcp_utility.h
+++ b/media/cast/net/rtcp/rtcp_utility.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef MEDIA_CAST_RTCP_RTCP_UTILITY_H_
-#define MEDIA_CAST_RTCP_RTCP_UTILITY_H_
+#ifndef MEDIA_CAST_NET_RTCP_RTCP_UTILITY_H_
+#define MEDIA_CAST_NET_RTCP_RTCP_UTILITY_H_
 
 #include "base/big_endian.h"
 #include "media/cast/logging/logging_defines.h"
@@ -135,7 +135,11 @@ void ConvertTimeTicksToNtp(const base::TimeTicks& time,
 base::TimeTicks ConvertNtpToTimeTicks(uint32_t ntp_seconds,
                                       uint32_t ntp_fractions);
 
+bool IsRtcpPacket(const uint8_t* packet, size_t length);
+
+uint32_t GetSsrcOfSender(const uint8_t* rtcp_buffer, size_t length);
+
 }  // namespace cast
 }  // namespace media
 
-#endif  // MEDIA_CAST_RTCP_RTCP_UTILITY_H_
+#endif  // MEDIA_CAST_NET_RTCP_RTCP_UTILITY_H_