Fix flakeyness in the timer test.

There were two problems.  First, I changed the API so you need to activate high
resolution timers, and that was not getting called.  So if nobody else was
activating them, the timers were definitely not high resolution anymore.

Secondarily, the test was too aggressive.  We set the resolution to 1ms
(via timeBeginPeriod on windows), which means that we could get up to ~1.5 *
1ms of slop.  Without the change, I was getting failures in about 1/800 runs.
With the new value (8500ms instead of 9000ms), I get zero failures in 5000
runs before I stopped trying.

BUG=none
TEST=self


Review URL: http://codereview.chromium.org/2927005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@52080 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 1 deletions

diff --git a/base/time_unittest.cc b/base/time_unittest.cc
index 76b357a..2950d74 100644
--- a/base/time_unittest.cc
+++ b/base/time_unittest.cc
@@ -118,11 +118,18 @@ TEST(TimeTicks, Deltas) {
 }
 
 TEST(TimeTicks, HighResNow) {
+#if defined(OS_WIN)
+  Time::ActivateHighResolutionTimer(true);
+#endif
+
   TimeTicks ticks_start = TimeTicks::HighResNow();
   PlatformThread::Sleep(10);
   TimeTicks ticks_stop = TimeTicks::HighResNow();
   TimeDelta delta = ticks_stop - ticks_start;
-  EXPECT_GE(delta.InMicroseconds(), 9000);
+
+  // In high res mode, we should be accurate to within 1.5x our
+  // best granularity.  On windows, that is 1ms, so use 1.5ms.
+  EXPECT_GE(delta.InMicroseconds(), 8500);
 }
 
 TEST(TimeDelta, FromAndIn) {