RefCounted types should not have public destructors, net/ edition

net/disk_cache/file.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.
 
 // See net/disk_cache/disk_cache.h for the public interface of the cache.
 
 #ifndef NET_DISK_CACHE_FILE_H_
 #define NET_DISK_CACHE_FILE_H_
 #pragma once
 
 #include "base/memory/ref_counted.h"
 #include "base/platform_file.h"
 #include "net/base/net_export.h"
 
 class FilePath;
 
 namespace disk_cache {
 
 // This interface is used to support asynchronous ReadData and WriteData calls.
 class FileIOCallback {
  public:
-  virtual ~FileIOCallback() {}
-
   // Notified of the actual number of bytes read or written. This value is
   // negative if an error occurred.
   virtual void OnFileIOComplete(int bytes_copied) = 0;
+
+ protected:
+  virtual ~FileIOCallback() {}
 };
 
 // Simple wrapper around a file that allows asynchronous operations.
 class NET_EXPORT_PRIVATE File : public base::RefCounted<File> {
   friend class base::RefCounted<File>;
  public:
   File();
   // mixed_mode set to true enables regular synchronous operations for the file.
   explicit File(bool mixed_mode);
 
@@ skipping 47 matching lines @@
   bool mixed_;
   base::PlatformFile platform_file_;  // Regular, asynchronous IO handle.
   base::PlatformFile sync_platform_file_;  // Synchronous IO handle.
 
   DISALLOW_COPY_AND_ASSIGN(File);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_FILE_H_