Change to Hi Res timers on Windows....

base/time_unittest.cc

 // Copyright (c) 2006-2008 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 <time.h>
 
 #include "base/platform_thread.h"
 #include "base/time.h"
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 68 matching lines @@
 TEST(Time, LocalMidnight) {
   Time::Exploded exploded;
   Time::Now().LocalMidnight().LocalExplode(&exploded);
   EXPECT_EQ(0, exploded.hour);
   EXPECT_EQ(0, exploded.minute);
   EXPECT_EQ(0, exploded.second);
   EXPECT_EQ(0, exploded.millisecond);
 }
 
 TEST(TimeTicks, Deltas) {
-  TimeTicks ticks_start = TimeTicks::Now();
-  PlatformThread::Sleep(10);
-  TimeTicks ticks_stop = TimeTicks::Now();
-  TimeDelta delta = ticks_stop - ticks_start;
-  EXPECT_GE(delta.InMilliseconds(), 10);
-  EXPECT_GE(delta.InMicroseconds(), 10000);
-  EXPECT_EQ(delta.InSeconds(), 0);
+  for (int index = 0; index < 500; index++) {
+    TimeTicks ticks_start = TimeTicks::Now();
+    PlatformThread::Sleep(10);
+    TimeTicks ticks_stop = TimeTicks::Now();
+    TimeDelta delta = ticks_stop - ticks_start;
+    // Note:  Although we asked for a 10ms sleep, if the
+    // time clock has a finer granularity than the Sleep()
+    // clock, it is quite possible to wakeup early.  Here
+    // is how that works:
+    //      Time(ms timer)      Time(us timer)
+    //          5                   5010
+    //          6                   6010
+    //          7                   7010
+    //          8                   8010
+    //          9                   9000
+    // Elapsed  4ms                 3990us
+    //
+    // Unfortunately, our InMilliseconds() function truncates
+    // rather than rounds.  We should consider fixing this
+    // so that our averages come out better.
+    EXPECT_GE(delta.InMilliseconds(), 9);
+    EXPECT_GE(delta.InMicroseconds(), 9000);
+    EXPECT_EQ(delta.InSeconds(), 0);
+  }
 }
 
-TEST(TimeTicks, UnreliableHighResNow) {
-  TimeTicks ticks_start = TimeTicks::UnreliableHighResNow();
+TEST(TimeTicks, HighResNow) {
+  TimeTicks ticks_start = TimeTicks::HighResNow();
   PlatformThread::Sleep(10);
-  TimeTicks ticks_stop = TimeTicks::UnreliableHighResNow();
+  TimeTicks ticks_stop = TimeTicks::HighResNow();
   TimeDelta delta = ticks_stop - ticks_start;
-  EXPECT_GE(delta.InMilliseconds(), 10);
+  EXPECT_GE(delta.InMicroseconds(), 9000);
 }
 
 TEST(TimeDelta, FromAndIn) {
   EXPECT_TRUE(TimeDelta::FromDays(2) == TimeDelta::FromHours(48));
   EXPECT_TRUE(TimeDelta::FromHours(3) == TimeDelta::FromMinutes(180));
   EXPECT_TRUE(TimeDelta::FromMinutes(2) == TimeDelta::FromSeconds(120));
   EXPECT_TRUE(TimeDelta::FromSeconds(2) == TimeDelta::FromMilliseconds(2000));
   EXPECT_TRUE(TimeDelta::FromMilliseconds(2) ==
               TimeDelta::FromMicroseconds(2000));
   EXPECT_EQ(13, TimeDelta::FromDays(13).InDays());
   EXPECT_EQ(13, TimeDelta::FromHours(13).InHours());
   EXPECT_EQ(13, TimeDelta::FromMinutes(13).InMinutes());
   EXPECT_EQ(13, TimeDelta::FromSeconds(13).InSeconds());
   EXPECT_EQ(13.0, TimeDelta::FromSeconds(13).InSecondsF());
   EXPECT_EQ(13, TimeDelta::FromMilliseconds(13).InMilliseconds());
   EXPECT_EQ(13.0, TimeDelta::FromMilliseconds(13).InMillisecondsF());
   EXPECT_EQ(13, TimeDelta::FromMicroseconds(13).InMicroseconds());
 }