Don't measure CPU time in timing out GPU watchdog.

content/gpu/gpu_watchdog_thread.h

Index: content/gpu/gpu_watchdog_thread.h
diff --git a/content/gpu/gpu_watchdog_thread.h b/content/gpu/gpu_watchdog_thread.h
index 4370d831168e234eb39bdf187e57f7dca617c9aa..9be3a39488d2a3b45cc39a7a275e0da8ad1f759d 100644
--- a/content/gpu/gpu_watchdog_thread.h
+++ b/content/gpu/gpu_watchdog_thread.h
@@ -88,20 +88,11 @@ class GpuWatchdogThread : public base::Thread,
   void OnSuspend() override;
   void OnResume() override;
 
-#if defined(OS_WIN)
-  base::TimeDelta GetWatchedThreadTime();
-#endif
-
   base::MessageLoop* watched_message_loop_;
   base::TimeDelta timeout_;
   volatile bool armed_;
   GpuWatchdogTaskObserver task_observer_;
 
-#if defined(OS_WIN)
-  void* watched_thread_handle_;
-  base::TimeDelta arm_cpu_time_;
-#endif
-
   // Time after which it's assumed that the computer has been suspended since
   // the task was posted.
   base::Time suspension_timeout_;