[rtp_rtcp] RTT intermidiate calculation use ntp time instead of milliseconds.

webrtc/modules/rtp_rtcp/source/time_util.h

Index: webrtc/modules/rtp_rtcp/source/time_util.h
diff --git a/webrtc/modules/rtp_rtcp/source/time_util.h b/webrtc/modules/rtp_rtcp/source/time_util.h
index 5b544ddf9abc0b0cc98fff993ebb4ba2010306e2..a876b14d56f35c1eb11dd8b352287cf15bcdf134 100644
--- a/webrtc/modules/rtp_rtcp/source/time_util.h
+++ b/webrtc/modules/rtp_rtcp/source/time_util.h
@@ -41,7 +41,8 @@ inline uint32_t CompactNtp(NtpTime ntp) {
 // Converts interval between compact ntp timestamps to milliseconds.
 // This interval can be upto ~18.2 hours (2^16 seconds).
 inline uint32_t CompactNtpIntervalToMs(uint32_t compact_ntp_interval) {
-  return static_cast<uint64_t>(compact_ntp_interval) * 1000 / (1 << 16);
+  uint64_t value = static_cast<uint64_t>(compact_ntp_interval);
+  return (value * 1000 + (1 << 15)) >> 16;
 }
 
 }  // namespace webrtc