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 9e18e44b0a2bf497d1a12e7f8d12ccc589bafe8f..fa5d275b94eb96dd56290199be8256c2b31985f4 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