Assert that thread-safe reference counting is used with...

chrome/browser/printing/print_job_worker_owner.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 CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_OWNER_H__
 #define CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_OWNER_H__
 
+#include "base/ref_counted.h"
 #include "printing/printing_context.h"
 
 class MessageLoop;
 
 namespace printing {
 
 class PrintJobWorker;
 class PrintSettings;
 
-class PrintJobWorkerOwner {
+class PrintJobWorkerOwner :
+    public base::RefCountedThreadSafe<PrintJobWorkerOwner> {
  public:
   virtual ~PrintJobWorkerOwner() {
   }
-  virtual void AddRef() = 0;
-  virtual void Release() = 0;
 
   // Finishes the initialization began by PrintJobWorker::Init(). Creates a
   // new PrintedDocument if necessary. Solely meant to be called by
   // PrintJobWorker.
   virtual void GetSettingsDone(const PrintSettings& new_settings,
                                PrintingContext::Result result) = 0;
 
   // Detach the PrintJobWorker associated to this object.
   virtual PrintJobWorker* DetachWorker(PrintJobWorkerOwner* new_owner) = 0;
 
   // Retrieves the message loop that is expected to process GetSettingsDone.
   virtual MessageLoop* message_loop() = 0;
 
   // Access the current settings.
   virtual const PrintSettings& settings() const = 0;
 
   // Cookie uniquely identifying the PrintedDocument and/or loaded settings.
   virtual int cookie() const = 0;
 };
 
 }  // namespace printing
 
 #endif  // CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_OWNER_H__