Printing: Convert PrintingContext into an interface implemented by the separate

chrome/browser/printing/print_job_worker.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_H__
 #define CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_H__
 #pragma once
 
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
 #include "base/task.h"
 #include "base/thread.h"
 #include "gfx/native_widget_types.h"
 #include "printing/page_number.h"
 #include "printing/printing_context.h"
 
 namespace printing {
 
 class PrintedDocument;
 class PrintedPage;
@@ skipping 34 matching lines @@
   void OnNewPage();
 
   // This is the only function that can be called in a thread.
   void Cancel();
 
   // Cancels the Print... dialog box if shown, noop otherwise.
   void DismissDialog();
 
  protected:
   // Retrieves the context for testing only.
-  PrintingContext& printing_context() { return printing_context_; }
+  PrintingContext* printing_context() { return printing_context_.get(); }
 
  private:
   // The shared NotificationService service can only be accessed from the UI
   // thread, so this class encloses the necessary information to send the
   // notification from the right thread. Most NOTIFY_PRINT_JOB_EVENT
   // notifications are sent this way, except USER_INIT_DONE, USER_INIT_CANCELED
   // and DEFAULT_INIT_DONE. These three are sent through PrintJob::InitDone().
   class NotificationTask;
   friend struct RunnableMethodTraits<PrintJobWorker>;
 
@@ skipping 17 matching lines @@
   // The callback used by PrintingContext::GetSettingsWithUI() to notify this
   // object that the print settings are set.  This is needed in order to bounce
   // back into the IO thread for GetSettingsDone().
   void GetSettingsWithUIDone(PrintingContext::Result result);
 #endif
 
   // Reports settings back to owner_.
   void GetSettingsDone(PrintingContext::Result result);
 
   // Information about the printer setting.
-  PrintingContext printing_context_;
+  scoped_ptr<PrintingContext> printing_context_;
 
   // The printed document. Only has read-only access.
   scoped_refptr<PrintedDocument> document_;
 
   // The print job owning this worker thread. It is guaranteed to outlive this
   // object.
   PrintJobWorkerOwner* owner_;
 
   // Current page number to print.
   PageNumber page_number_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintJobWorker);
 };
 
 }  // namespace printing
 
 template <>
 struct RunnableMethodTraits<printing::PrintJobWorker> {
   void RetainCallee(printing::PrintJobWorker* obj);
   void ReleaseCallee(printing::PrintJobWorker* obj);
  private:
   scoped_refptr<printing::PrintJobWorkerOwner> owner_;
 };
 
 #endif  // CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_H__