Implement Time::ThreadNow() on Mac.

base/time/time_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/time/time.h"
 
 #include <time.h>
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
@@ skipping 621 matching lines @@
 }
 
 TEST(TimeTicks, HighResNow) {
   HighResClockTest(&TimeTicks::HighResNow);
 }
 
 TEST(TimeTicks, ThreadNow) {
   if (TimeTicks::IsThreadNowSupported()) {
     TimeTicks begin = TimeTicks::Now();
     TimeTicks begin_thread = TimeTicks::ThreadNow();
-    // Sleep for 10 milliseconds to get the thread de-scheduled
+    // Make sure that ThreadNow value is non-zero.
+    EXPECT_GT(begin_thread, TimeTicks());
+    // Sleep for 10 milliseconds to get the thread de-scheduled.
     base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(10));
     TimeTicks end_thread = TimeTicks::ThreadNow();
     TimeTicks end = TimeTicks::Now();
     TimeDelta delta = end - begin;
     TimeDelta delta_thread = end_thread - begin_thread;
+    // Make sure that some thread time have elapsed.

[Nico, 2013/11/05 23:20:06]

s/have/has/

+    EXPECT_GT(delta_thread.InMicroseconds(), 0);
+    // But the thread time is at least 9ms less than clock time.
     TimeDelta difference = delta - delta_thread;
     EXPECT_GE(difference.InMicroseconds(), 9000);
   }
 }
 
 TEST(TimeTicks, NowFromSystemTraceTime) {
   // Re-use HighResNow test for now since clock properties are identical.
   HighResClockTest(&TimeTicks::NowFromSystemTraceTime);
 }
 
@@ skipping 48 matching lines @@
   exploded.minute = 0;
   exploded.second = 0;
   exploded.millisecond = 0;
   Time t = Time::FromUTCExploded(exploded);
   // Unix 1970 epoch.
   EXPECT_EQ(GG_INT64_C(11644473600000000), t.ToInternalValue());
 
   // We can't test 1601 epoch, since the system time functions on Linux
   // only compute years starting from 1900.
 }