Cast:Adding cast_transport_config and cleaning up

media/cast/rtcp/rtcp.cc

Index: media/cast/rtcp/rtcp.cc
diff --git a/media/cast/rtcp/rtcp.cc b/media/cast/rtcp/rtcp.cc
index 090a8080ec088d0e9d67e7604afb5692c6626282..922487591cfded5946ed669ed07f8005370d4965 100644
--- a/media/cast/rtcp/rtcp.cc
+++ b/media/cast/rtcp/rtcp.cc
@@ -216,7 +216,8 @@ bool Rtcp::IsRtcpPacket(const uint8* packet, size_t length) {
   if (length < kMinLengthOfRtcp) return false;
 
   uint8 packet_type = packet[1];
-  if (packet_type >= kPacketTypeLow && packet_type <= kPacketTypeHigh) {
+  if (packet_type >= transport::kPacketTypeLow &&
+      packet_type <= transport::kPacketTypeHigh) {
     return true;
   }
   return false;