win: Ref-counted classes should have non-public destructors.

net/proxy/dhcp_proxy_script_adapter_fetcher_win.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 NET_PROXY_DHCP_PROXY_SCRIPT_ADAPTER_FETCHER_WIN_H_
 #define NET_PROXY_DHCP_PROXY_SCRIPT_ADAPTER_FETCHER_WIN_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 102 matching lines @@
 
   State state() const;
 
   // This inner class encapsulates work done on a worker pool thread.
   // By using a separate object, we can keep the main object completely
   // thread safe and let it be non-refcounted.
   class NET_EXPORT_PRIVATE DhcpQuery
       : public base::RefCountedThreadSafe<DhcpQuery> {
    public:
     DhcpQuery();
-    virtual ~DhcpQuery();
 
     // This method should run on a worker pool thread, via PostTaskAndReply.
     // After it has run, the |url()| method on this object will return the
     // URL retrieved.
     void GetPacURLForAdapter(const std::string& adapter_name);
 
     // Returns the URL retrieved for the given adapter, once the task has run.
     const std::string& url() const;
 
    protected:
     // Virtual method introduced to allow unit testing.
     virtual std::string ImplGetPacURLFromDhcp(const std::string& adapter_name);
 
+    friend class base::RefCountedThreadSafe<DhcpQuery>;
+    virtual ~DhcpQuery();
+
    private:
     // The URL retrieved for the given adapter.
     std::string url_;
 
     DISALLOW_COPY_AND_ASSIGN(DhcpQuery);
   };
 
   // Virtual methods introduced to allow unit testing.
   virtual ProxyScriptFetcher* ImplCreateScriptFetcher();
   virtual DhcpQuery* ImplCreateDhcpQuery();
@@ skipping 32 matching lines @@
   base::OneShotTimer<DhcpProxyScriptAdapterFetcher> wait_timer_;
 
   URLRequestContext* const url_request_context_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(DhcpProxyScriptAdapterFetcher);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_DHCP_PROXY_SCRIPT_ADAPTER_FETCHER_WIN_H_