Change NtpTime representation to single uint64_t

webrtc/system_wrappers/source/ntp_time_unittest.cc

 /*
  *  Copyright (c) 2014 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.
  */
 
@@ skipping 36 matching lines @@
 }
 
 TEST(NtpTimeTest, ToMsMeansToNtpMilliseconds) {
   SimulatedClock clock(0x123456789abc);
 
   NtpTime ntp = clock.CurrentNtpTime();
   EXPECT_EQ(ntp.ToMs(), Clock::NtpToMs(ntp.seconds(), ntp.fractions()));
   EXPECT_EQ(ntp.ToMs(), clock.CurrentNtpInMilliseconds());
 }
 
+TEST(NtpTimeTest, CanExplicitlyConvertToAndFromUint64) {
+  uint64_t untyped_time = 0x123456789;
+  NtpTime time(untyped_time);
+  EXPECT_EQ(untyped_time, static_cast<uint64_t>(time));
+  EXPECT_EQ(NtpTime(0x12345678, 0x90abcdef), NtpTime(0x1234567890abcdef));
+}
+
 }  // namespace
 }  // namespace webrtc