2nd try:...

base/time.h

Index: base/time.h
===================================================================
--- base/time.h	(revision 63177)
+++ base/time.h	(working copy)
@@ -283,10 +283,16 @@
   // Activates or deactivates the high resolution timer based on the |activate|
   // flag.  If the HighResolutionTimer is not Enabled (see
   // EnableHighResolutionTimer), this function will return false.  Otherwise
-  // returns true.
+  // returns true.  Each successful activate call must be paired with a
+  // subsequent deactivate call.
   // All callers to activate the high resolution timer must eventually call
   // this function to deactivate the high resolution timer.
   static bool ActivateHighResolutionTimer(bool activate);
+
+  // Returns true if the high resolution timer is both enabled and activated.
+  // This is provided for testing only, and is not tracked in a thread-safe
+  // way.
+  static bool IsHighResolutionTimerInUse();
 #endif
 
   // Converts an exploded structure representing either the local time or UTC
@@ -405,6 +411,9 @@
   // when using battery power, we might elect to prevent high speed timers
   // which would draw more power.
   static bool high_resolution_timer_enabled_;
+  // Count of activations on the high resolution timer.  Only use in tests
+  // which are single threaded.
+  static int high_resolution_timer_activated_;
 #endif
 
   // Time in microseconds in UTC.