Cast: IPC glue between cast library transport and encoders.

media/cast/transport/cast_transport_sender.h

Index: media/cast/transport/cast_transport_sender.h
diff --git a/media/cast/transport/cast_transport_sender.h b/media/cast/transport/cast_transport_sender.h
index 74c533e64e49cfe16a53de93d168406edda90287..6429719327910d65fadf3e3db344198971879578 100644
--- a/media/cast/transport/cast_transport_sender.h
+++ b/media/cast/transport/cast_transport_sender.h
@@ -33,13 +33,16 @@
 
 namespace media {
 namespace cast {
+
+class PacketReceiver;
+
 namespace transport {
 
 typedef base::Callback<void(CastTransportStatus status)>
     CastTransportStatusCallback;
 
 typedef base::Callback<
-    void(RtcpSenderInfo& sender_info, base::TimeTicks time_sent,
+    void(const RtcpSenderInfo& sender_info, base::TimeTicks time_sent,
          uint32 rtp_timestamp)> CastTransportRtpStatistics;
 
 // The application should only trigger this class from the transport thread.