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

base/message_pump.h

Index: base/message_pump.h
diff --git a/base/message_pump.h b/base/message_pump.h
index d7aaf0c51a6b16a44cae117dcb2be1664cd7fa7e..dd2cf67aac8900e0dd4a186f2a3b9cc0c6cb683d 100644
--- a/base/message_pump.h
+++ b/base/message_pump.h
@@ -43,7 +43,6 @@ class BASE_EXPORT MessagePump : public RefCountedThreadSafe<MessagePump> {
   };
 
   MessagePump();
-  virtual ~MessagePump();
 
   // The Run method is called to enter the message pump's run loop.
   //
@@ -120,6 +119,10 @@ class BASE_EXPORT MessagePump : public RefCountedThreadSafe<MessagePump> {
   // cancelling any pending DoDelayedWork callback.  This method may only be
   // used on the thread that called Run.
   virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) = 0;
+
+ protected:
+  virtual ~MessagePump();
+  friend class RefCountedThreadSafe<MessagePump>;
 };
 
 }  // namespace base