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

media/cast/net/rtp/rtp_parser.h

Index: media/cast/net/rtp/rtp_parser.h
diff --git a/media/cast/net/rtp/rtp_parser.h b/media/cast/net/rtp/rtp_parser.h
index d9e6ab97ca1ef0277b45ddcf43139f313ebfdd04..3e8e2f1dfe5b32ba1969adfa54e1bbc2999c3d2b 100644
--- a/media/cast/net/rtp/rtp_parser.h
+++ b/media/cast/net/rtp/rtp_parser.h
@@ -38,6 +38,11 @@ class RtpParser {
  private:
   const uint32 expected_sender_ssrc_;
   const uint8 expected_payload_type_;
+
+  // Tracks recently-parsed RTP timestamps so that it can expand the truncated
+  // values found in packets.
+  RtpTimeTicks last_parsed_rtp_timestamp_;
+
   FrameIdWrapHelper frame_id_wrap_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(RtpParser);