RefCounted types should not have public destructors, delegate cleanup

chrome/browser/extensions/app_notify_channel_ui.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_APP_NOTIFY_CHANNEL_UI_H_
 #define CHROME_BROWSER_EXTENSIONS_APP_NOTIFY_CHANNEL_UI_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 15 matching lines @@
     NO_INFOBAR,
 
     // Ask if the app can show notifications.
     NOTIFICATION_INFOBAR,
   };
 
   class Delegate {
    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
   // setup is complete or cancelled. This should only be called once per
   // instance.
   virtual void PromptSyncSetup(Delegate* delegate) = 0;
 };
 
 
 class AppNotifyChannelUIImpl : public AppNotifyChannelUI,
@@ skipping 38 matching lines @@
   // after ShowLoginDialog is called and before the wizard is
   // actually visible to the user. So we record if the wizard was
   // shown to user and then wait for wizard to get dismissed.
   // See crbug.com/101842.
   bool wizard_shown_to_user_;
 
   DISALLOW_COPY_AND_ASSIGN(AppNotifyChannelUIImpl);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_APP_NOTIFY_CHANNEL_UI_H_