Added framer to cast.

media/cast/rtp_common/rtp_defines.h

Index: media/cast/rtp_common/rtp_defines.h
diff --git a/media/cast/rtp_common/rtp_defines.h b/media/cast/rtp_common/rtp_defines.h
new file mode 100644
index 0000000000000000000000000000000000000000..1bd0fea0ff6f627953377ff4f3798e3b6238d813
--- /dev/null
+++ b/media/cast/rtp_common/rtp_defines.h
@@ -0,0 +1,64 @@
+#ifndef MEDIA_CAST_RTP_COMMON_RTP_DEFINES_H_
+#define MEDIA_CAST_RTP_COMMON_RTP_DEFINES_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 {
+
+const uint8 kRtpMarkerBitMask = 0x80;
+
+struct RtpCastHeader {
+  void InitRTPVideoHeaderCast() {
+    is_key_frame = false;
+    frame_id = 0;
+    packet_id = 0;
+    max_packet_id = 0;
+    is_reference = false;
+    reference_frame_id = 0;
+  }
+  webrtc::WebRtcRTPHeader webrtc;
+  bool is_key_frame;
+  uint8 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.
+  uint8 reference_frame_id;
+};
+
+class RtpPayloadFeedback {
+ public:
+  virtual void CastFeedback(const RtcpCastMessage& cast_feedback) = 0;
+  virtual void RequestKeyFrame() = 0;  // TODO(pwestin): can we remove this?
+
+ protected:
+  virtual ~RtpPayloadFeedback() {}
+};
+
+inline bool IsNewerFrameId(uint8 frame_id, uint8 prev_frame_id) {
+  return (frame_id != prev_frame_id) &&
+      static_cast<uint8>(frame_id - prev_frame_id) < 0x80;
+}
+
+inline bool IsOlderFrameId(uint8 frame_id, uint8 prev_frame_id) {
+  return (frame_id == prev_frame_id) || IsNewerFrameId(prev_frame_id, frame_id);
+}
+
+inline bool IsNewerPacketId(uint16 packet_id, uint16 prev_packet_id) {
+  return (packet_id != prev_packet_id) &&
+      static_cast<uint16>(packet_id - prev_packet_id) < 0x8000;
+}
+
+inline bool IsNewerSequenceNumber(uint16 sequence_number,
+                                  uint16 prev_sequence_number) {
+  // Same function as IsNewerPacketId just different data and name.
+  return IsNewerPacketId(sequence_number, prev_sequence_number);
+}
+
+}  // namespace cast
+}  // namespace media
+
+#endif  // MEDIA_CAST_RTP_COMMON_RTP_DEFINES_H_