Fix base::CPU detection.

base/time_win_unittest.cc

 // Copyright (c) 2011 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 <windows.h>
 #include <mmsystem.h>
 #include <process.h>
 
 #include "base/threading/platform_thread.h"
 #include "base/time.h"
@@ skipping 190 matching lines @@
     // buildbots, some of which are VMs.  These machines can run horribly
     // slow, and there is really no value for checking against a max timer.
     //EXPECT_LT((stop - start).InMilliseconds(), kMaxTime);
     printf("%s: %1.2fus per call\n", cases[test_case].description,
       (stop - start).InMillisecondsF() * 1000 / kLoops);
     test_case++;
   }
 }
 
 TEST(TimeTicks, Drift) {
+  // If QPC is disabled, this isn't measuring anything.
+  if (!TimeTicks::IsHighResClockWorking())
+    return;
+
   const int kIterations = 100;
   int64 total_drift = 0;
 
   for (int i = 0; i < kIterations; ++i) {
     int64 drift_microseconds = TimeTicks::GetQPCDriftMicroseconds();
 
     // Make sure the drift never exceeds our limit.
     EXPECT_LT(drift_microseconds, 50000);
 
     // Sleep for a few milliseconds (note that it means 1000 microseconds).
     // If we check the drift too frequently, it's going to increase
     // monotonically, making our measurement less realistic.
     base::PlatformThread::Sleep(
         base::TimeDelta::FromMilliseconds((i % 2 == 0) ? 1 : 2));
 
     total_drift += drift_microseconds;
   }
 
   // Sanity check. We expect some time drift to occur, especially across
-  // the number of iterations we do. However, if the QPC is disabled, this
-  // is not measuring anything (drift is zero in that case).
+  // the number of iterations we do.
   EXPECT_LT(0, total_drift);
 
   printf("average time drift in microseconds: %lld\n",
          total_drift / kIterations);
 }