PrintPreview: Added a helper function to get print job settings from dictionary.

printing/printing_context.h

 // Copyright (c) 2011 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_PRINTING_CONTEXT_H_
 #define PRINTING_PRINTING_CONTEXT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 86 matching lines @@
   const PrintSettings& settings() const {
     return settings_;
   }
 
  protected:
   explicit PrintingContext(const std::string& app_locale);
 
   // Reinitializes the settings for object reuse.
   void ResetSettings();
 
+  // Extracts print job settings from |settings|. Out parameters can be NULL.
+  // Returns true if all non-NULL out parameters are successfully extracted
+  // from |settings| else returns false.
+  bool GetSettingsFromDict(const DictionaryValue& settings,
+                           bool* landscape,
+                           string16* printerName);
+
   // Does bookkeeping when an error occurs.
   PrintingContext::Result OnError();
 
   // Complete print context settings.
   PrintSettings settings_;
 
   // The dialog box has been dismissed.
   volatile bool dialog_box_dismissed_;
 
   // Is a print job being done.
   volatile bool in_print_job_;
 
   // Did the user cancel the print job.
   volatile bool abort_printing_;
 
   // The application locale.
   std::string app_locale_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintingContext);
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_PRINTING_CONTEXT_H_