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

media/cast/sender/h264_vt_encoder.cc

Index: media/cast/sender/h264_vt_encoder.cc
diff --git a/media/cast/sender/h264_vt_encoder.cc b/media/cast/sender/h264_vt_encoder.cc
index c9f9330caed979f76bd44b98c2e6cba25c0e87c9..b8651def551a2dca9082bb2ee16a9bf1267f06f8 100644
--- a/media/cast/sender/h264_vt_encoder.cc
+++ b/media/cast/sender/h264_vt_encoder.cc
@@ -17,7 +17,7 @@
 #include "base/synchronization/lock.h"
 #include "media/base/mac/corevideo_glue.h"
 #include "media/base/mac/video_frame_mac.h"
-#include "media/cast/cast_defines.h"
+#include "media/cast/common/rtp_time.h"
 #include "media/cast/constants.h"
 #include "media/cast/sender/video_frame_factory.h"
 
@@ -28,11 +28,11 @@ namespace {
 
 // Container for the associated data of a video frame being processed.
 struct InProgressFrameEncode {
-  const RtpTimestamp rtp_timestamp;
+  const RtpTimeTicks rtp_timestamp;
   const base::TimeTicks reference_time;
   const VideoEncoder::FrameEncodedCallback frame_encoded_callback;
 
-  InProgressFrameEncode(RtpTimestamp rtp,
+  InProgressFrameEncode(RtpTimeTicks rtp,
                         base::TimeTicks r_time,
                         VideoEncoder::FrameEncodedCallback callback)
       : rtp_timestamp(rtp),
@@ -568,7 +568,7 @@ bool H264VideoToolboxEncoder::EncodeVideoFrame(
   // Wrap information we'll need after the frame is encoded in a heap object.
   // We'll get the pointer back from the VideoToolbox completion callback.
   scoped_ptr<InProgressFrameEncode> request(new InProgressFrameEncode(
-      TimeDeltaToRtpDelta(video_frame->timestamp(), kVideoFrequency),
+      RtpTimeTicks::FromTimeDelta(video_frame->timestamp(), kVideoFrequency),
       reference_time, frame_encoded_callback));
 
   // Build a suitable frame properties dictionary for keyframes.