RefCounted types should not have public destructors, delegate cleanup

chrome/browser/extensions/app_notify_channel_ui.h

Index: chrome/browser/extensions/app_notify_channel_ui.h
diff --git a/chrome/browser/extensions/app_notify_channel_ui.h b/chrome/browser/extensions/app_notify_channel_ui.h
index e345af8606794930c406336f0190c4c2b5048f61..99632ab8bd72175992f3311e18925e338a58ea60 100644
--- a/chrome/browser/extensions/app_notify_channel_ui.h
+++ b/chrome/browser/extensions/app_notify_channel_ui.h
@@ -33,6 +33,9 @@ class AppNotifyChannelUI {
    public:
     // A callback for whether the user successfully set up sync or not.
     virtual void OnSyncSetupResult(bool enabled) = 0;
+
+   protected:
+    virtual ~Delegate() {}
   };
 
   // Shows a prompt for sync setup - |delegate| will be called back later when