[Cast] Aggressively send sender reports until first receiver report is received.

media/cast/rtp_timestamp_helper.cc

Index: media/cast/rtp_timestamp_helper.cc
diff --git a/media/cast/rtp_timestamp_helper.cc b/media/cast/rtp_timestamp_helper.cc
index a0c56c09eabdde82e7c6d4e1208813c672fb64ce..3349e7b33fd4adf9d8a176c05984c69801950879 100644
--- a/media/cast/rtp_timestamp_helper.cc
+++ b/media/cast/rtp_timestamp_helper.cc
@@ -19,9 +19,10 @@ bool RtpTimestampHelper::GetCurrentTimeAsRtpTimestamp(
     const base::TimeTicks& now, uint32* rtp_timestamp) const {
   if (last_capture_time_.is_null())
     return false;
-  base::TimeDelta elapsed_time = now - last_capture_time_;
-  *rtp_timestamp = last_rtp_timestamp_ + elapsed_time.InMilliseconds() *

[miu, 2014/05/23 22:41:28]

Not sure whether this was hurting anything, but the truncation in precision
(micros-->millis) irritated me too much.

-      frequency_ / base::Time::kMillisecondsPerSecond;
+  const base::TimeDelta elapsed_time = now - last_capture_time_;
+  const int64 rtp_delta =
+      elapsed_time * frequency_ / base::TimeDelta::FromSeconds(1);

[hubbe, 2014/05/23 22:47:34]

I think this will wrap around actually...

+  *rtp_timestamp = last_rtp_timestamp_ + static_cast<uint32>(rtp_delta);
   return true;
 }