RefCounted types should not have public destructors, content/ remaining bits

content/public/browser/indexed_db_context.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 CONTENT_PUBLIC_BROWSER_INDEXED_DB_CONTEXT_H_
 #define CONTENT_PUBLIC_BROWSER_INDEXED_DB_CONTEXT_H_
 #pragma once
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 
 class GURL;
 
 namespace base {
 class Time;
 }
 
 namespace content {
 
 // Represents the per-BrowserContext IndexedDB data.
 // Call these methods only on the WebKit thread.
 class IndexedDBContext : public base::RefCountedThreadSafe<IndexedDBContext> {
  public:
-  virtual ~IndexedDBContext() {}
-
   // Methods used in response to QuotaManager requests.
   virtual std::vector<GURL> GetAllOrigins() = 0;
   virtual int64 GetOriginDiskUsage(const GURL& origin_url) = 0;
   virtual base::Time GetOriginLastModified(const GURL& origin_url) = 0;
 
   // Deletes all indexed db files for the given origin.
   virtual void DeleteForOrigin(const GURL& origin_url) = 0;
 
   // Get the file name of the local storage file for the given origin.
   virtual FilePath GetFilePathForTesting(const string16& origin_id) const = 0;
+
+ protected:
+  friend class base::RefCountedThreadSafe<IndexedDBContext>;
+  virtual ~IndexedDBContext() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_INDEXED_DB_CONTEXT_H_