replace NtpTime->Clock with Clock->NtpTime dependency

webrtc/modules/rtp_rtcp/source/time_util.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_
 
 #include <stdint.h>
 
 #include "webrtc/system_wrappers/include/ntp_time.h"
 
 namespace webrtc {
 
 // Converts NTP timestamp to RTP timestamp.
 inline uint32_t NtpToRtp(NtpTime ntp, uint32_t freq) {
   uint32_t tmp = (static_cast<uint64_t>(ntp.fractions()) * freq) >> 32;
   return ntp.seconds() * freq + tmp;
 }
-// Return the current RTP timestamp from the NTP timestamp
-// returned by the specified clock.
-inline uint32_t CurrentRtp(const Clock& clock, uint32_t freq) {
-  return NtpToRtp(NtpTime(clock), freq);
-}
 
 // Helper function for compact ntp representation:
 // RFC 3550, Section 4. Time Format.
 // Wallclock time is represented using the timestamp format of
 // the Network Time Protocol (NTP).
 // ...
 // In some fields where a more compact representation is
 // appropriate, only the middle 32 bits are used; that is, the low 16
 // bits of the integer part and the high 16 bits of the fractional part.
 inline uint32_t CompactNtp(NtpTime ntp) {
   return (ntp.seconds() << 16) | (ntp.fractions() >> 16);
 }
 // Converts interval between compact ntp timestamps to milliseconds.
 // This interval can be up to ~9.1 hours (2^15 seconds).
 // Values close to 2^16 seconds consider negative and result in minimum rtt = 1.
 int64_t CompactNtpRttToMs(uint32_t compact_ntp_interval);
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_TIME_UTIL_H_