[Cast] Remove AudioDecoder's dependency on WebRTC, and refactor/clean-up AudioReceiver.

media/cast/rtp_receiver/rtp_parser/rtp_parser.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/cast/rtp_receiver/rtp_parser/rtp_parser.h"
 
 #include "base/big_endian.h"
 #include "base/logging.h"
 #include "media/cast/cast_defines.h"
 #include "media/cast/rtp_receiver/rtp_receiver.h"
@@ skipping 94 matching lines @@
     data_ptr += kRtpCastHeaderLength;
     data_length -= kRtpCastHeaderLength;
   } else {
     data_ptr += kRtpCastHeaderLength - 1;
     data_length -= kRtpCastHeaderLength - 1;
   }
 
   if (rtp_header->max_packet_id < rtp_header->packet_id)
     return false;
 
-  data_callback_->OnReceivedPayloadData(data_ptr, data_length, rtp_header);
+  data_callback_->OnReceivedPayloadData(data_ptr, data_length, *rtp_header);
   return true;
 }
 
 }  // namespace cast
 }  // namespace media