First patch in making destructors of refcounted objects private.

printing/printed_page.h

 // Copyright (c) 2006-2008 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 PRINTING_PRINTED_PAGE_H_
 #define PRINTING_PRINTED_PAGE_H_
 
 #include "base/gfx/rect.h"
 #include "base/gfx/size.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "printing/native_metafile.h"
 
 namespace printing {
 
 // Contains the data to reproduce a printed page, either on screen or on
 // paper. Once created, this object is immutable. It has no reference to the
 // PrintedDocument containing this page.
 // Note: May be accessed from many threads at the same time. This is an non
 // issue since this object is immutable. The reason is that a page may be
 // printed and be displayed at the same time.
 class PrintedPage : public base::RefCountedThreadSafe<PrintedPage> {
  public:
   PrintedPage(int page_number,
               NativeMetafile* native_metafile,
               const gfx::Size& page_size);
-  ~PrintedPage();
 
   // Getters
   int page_number() const { return page_number_; }
   const NativeMetafile* native_metafile() const;
   const gfx::Size& page_size() const { return page_size_; }
 
  private:
+  friend class base::RefCountedThreadSafe<PrintedPage>;
+
+  ~PrintedPage();
+
   // Page number inside the printed document.
   const int page_number_;
 
   // Actual paint data.
   const scoped_ptr<NativeMetafile> native_metafile_;
 
   // The physical page size. To support multiple page formats inside on print
   // job.
   const gfx::Size page_size_;
 
   DISALLOW_EVIL_CONSTRUCTORS(PrintedPage);
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_PRINTED_PAGE_H_