replace NtpTime->Clock with Clock->NtpTime dependency

webrtc/system_wrappers/source/clock.cc

Index: webrtc/system_wrappers/source/clock.cc
diff --git a/webrtc/system_wrappers/source/clock.cc b/webrtc/system_wrappers/source/clock.cc
index 05dabd8538ccfc5de82585773a2637f6a4428a46..f31556fc4ff38b1073877bdd2ea8ee264276dfec 100644
--- a/webrtc/system_wrappers/source/clock.cc
+++ b/webrtc/system_wrappers/source/clock.cc
@@ -25,12 +25,11 @@
 
 namespace webrtc {
 
-const double kNtpFracPerMs = 4.294967296E6;
-
-int64_t Clock::NtpToMs(uint32_t ntp_secs, uint32_t ntp_frac) {
-  const double ntp_frac_ms = static_cast<double>(ntp_frac) / kNtpFracPerMs;
-  return 1000 * static_cast<int64_t>(ntp_secs) +
-      static_cast<int64_t>(ntp_frac_ms + 0.5);
+NtpTime Clock::CurrentNtpTime() const {
+  uint32_t seconds;
+  uint32_t fractions;
+  CurrentNtp(seconds, fractions);
+  return NtpTime(seconds, fractions);
 }
 
 class RealTimeClock : public Clock {