RefCounted types should not have public destructors, base/ edition

base/synchronization/waitable_event_watcher.h

Index: base/synchronization/waitable_event_watcher.h
diff --git a/base/synchronization/waitable_event_watcher.h b/base/synchronization/waitable_event_watcher.h
index 1512acc87250f45918bb3158e97636d79b660b22..27364027b83b1ed7d38a8bd5470eb7172fb5588b 100644
--- a/base/synchronization/waitable_event_watcher.h
+++ b/base/synchronization/waitable_event_watcher.h
@@ -72,8 +72,6 @@ class BASE_EXPORT WaitableEventWatcher
 
   class BASE_EXPORT Delegate {
    public:
-    virtual ~Delegate() { }
-
     // -------------------------------------------------------------------------
     // This is called on the MessageLoop thread when WaitableEvent has been
     // signaled.
@@ -83,6 +81,9 @@ class BASE_EXPORT WaitableEventWatcher
     // the past.
     // -------------------------------------------------------------------------
     virtual void OnWaitableEventSignaled(WaitableEvent* waitable_event) = 0;
+
+   protected:
+    virtual ~Delegate() { }
   };
 
   // ---------------------------------------------------------------------------