Fix race in base::Timer when SetTaskRunner() is used

base/timer/timer.h

Index: base/timer/timer.h
diff --git a/base/timer/timer.h b/base/timer/timer.h
index 88958d4ad65a3abef8976483d758014e097b8b82..7b67498b3f8ba4654a0e36e6ccbe30a2ddcda111 100644
--- a/base/timer/timer.h
+++ b/base/timer/timer.h
@@ -154,11 +154,6 @@ class BASE_EXPORT Timer {
   // and |desired_run_time_| are reset to Now() + delay.
   void PostNewScheduledTask(TimeDelta delay);
 
-  // Returns the task runner on which the task should be scheduled. If the
-  // corresponding |task_runner_| field is null, the task runner for the current
-  // sequence is returned.
-  scoped_refptr<SequencedTaskRunner> GetTaskRunner();
-
   // Disable |scheduled_task_| and abandon it so that it no longer refers back
   // to this object.
   void AbandonScheduledTask();