Replace uses of raw uint32's with a type-checked RtpTimeTicks data type.

media/cast/net/rtp/rtp_packetizer.h

Index: media/cast/net/rtp/rtp_packetizer.h
diff --git a/media/cast/net/rtp/rtp_packetizer.h b/media/cast/net/rtp/rtp_packetizer.h
index 034a74a2a50decfec20c0e7b277f616a276f502d..ab304fb79e582a77c9ef0ba2a8f33769dc8588d8 100644
--- a/media/cast/net/rtp/rtp_packetizer.h
+++ b/media/cast/net/rtp/rtp_packetizer.h
@@ -10,6 +10,7 @@
 #include <map>
 
 #include "base/time/time.h"
+#include "media/cast/common/rtp_time.h"
 #include "media/cast/net/rtp/packet_storage.h"
 
 namespace base {
@@ -54,15 +55,15 @@ class RtpPacketizer {
   size_t send_octet_count() const { return send_octet_count_; }
 
  private:
-  void BuildCommonRTPheader(Packet* packet, bool marker_bit, uint32 time_stamp);
+  void BuildCommonRTPheader(Packet* packet,
+                            bool marker_bit,
+                            RtpTimeTicks rtp_timestamp);
 
   RtpPacketizerConfig config_;
   PacedSender* const transport_;  // Not owned by this class.
   PacketStorage* packet_storage_;
 
   uint16 sequence_number_;
-  uint32 rtp_timestamp_;
-  uint16 packet_id_;
 
   size_t send_packet_count_;
   size_t send_octet_count_;