[Cast] Clean-up RtpCastHeader and RtpParser, removing the last WebRTC dependency.

media/cast/rtp_receiver/rtp_receiver_defines.h

Index: media/cast/rtp_receiver/rtp_receiver_defines.h
diff --git a/media/cast/rtp_receiver/rtp_receiver_defines.h b/media/cast/rtp_receiver/rtp_receiver_defines.h
index 112f1723776ec2400b90a909a2f423a09f6f0833..d907436f4896cf69b85f924e60b0d032d427b138 100644
--- a/media/cast/rtp_receiver/rtp_receiver_defines.h
+++ b/media/cast/rtp_receiver/rtp_receiver_defines.h
@@ -8,27 +8,25 @@
 #include "base/basictypes.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/rtcp/rtcp_defines.h"
-#include "third_party/webrtc/modules/interface/module_common_types.h"
 
 namespace media {
 namespace cast {
 
 struct RtpCastHeader {
-  RtpCastHeader() {
-    is_key_frame = false;
-    frame_id = 0;
-    packet_id = 0;
-    max_packet_id = 0;
-    is_reference = false;
-    reference_frame_id = 0;
-  }
-  webrtc::WebRtcRTPHeader webrtc;
+  RtpCastHeader();
+
+  // Elements from RTP packet header.
+  bool marker;
+  uint8 payload_type;
+  uint16 sequence_number;
+  uint32 rtp_timestamp;
+  uint32 sender_ssrc;
+
+  // Elements from Cast header (at beginning of RTP payload).
   bool is_key_frame;
   uint32 frame_id;
   uint16 packet_id;
   uint16 max_packet_id;
-  bool is_reference;  // Set to true if the previous frame is not available,
-                      // and the reference frame id  is available.
   uint32 reference_frame_id;
 };
 
@@ -37,7 +35,7 @@ class RtpPayloadFeedback {
   virtual void CastFeedback(const RtcpCastMessage& cast_feedback) = 0;
 
  protected:
-  virtual ~RtpPayloadFeedback() {}
+  virtual ~RtpPayloadFeedback();
 };
 
 }  // namespace cast