Objects that derive from RefCounted/RefCountedThreadSafe should not have public dtors.

base/message_pump_libevent.h

Index: base/message_pump_libevent.h
diff --git a/base/message_pump_libevent.h b/base/message_pump_libevent.h
index b12af703dae0c5fd5830613428616ac01db4b11b..24c7420b37a8fe6c54330e81e1e08a81266d61f6 100644
--- a/base/message_pump_libevent.h
+++ b/base/message_pump_libevent.h
@@ -100,7 +100,6 @@ class BASE_EXPORT MessagePumpLibevent : public MessagePump {
   };
 
   MessagePumpLibevent();
-  virtual ~MessagePumpLibevent();
 
   // Have the current thread's message loop watch for a a situation in which
   // reading/writing to the FD can be performed without blocking.
@@ -129,6 +128,9 @@ class BASE_EXPORT MessagePumpLibevent : public MessagePump {
   virtual void ScheduleWork() OVERRIDE;
   virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) OVERRIDE;
 
+ protected:
+  virtual ~MessagePumpLibevent();
+
  private:
   friend class MessagePumpLibeventTest;