De-duplicate job_settings parsing code.

printing/print_dialog_gtk_interface.h

Index: printing/print_dialog_gtk_interface.h
diff --git a/printing/print_dialog_gtk_interface.h b/printing/print_dialog_gtk_interface.h
index b3618374f40a55ff0dae7086a7da7bd12c4c2686..5a8926f1eb4b762bd3862c793f80babf34feab88 100644
--- a/printing/print_dialog_gtk_interface.h
+++ b/printing/print_dialog_gtk_interface.h
@@ -22,12 +22,12 @@ class PrintDialogGtkInterface {
   // Tell the dialog to use the default print setting.
   virtual void UseDefaultSettings() = 0;
 
-  // Update the dialog to use |job_settings| and |ranges|, where |job_settings|
-  // is a dictionary of settings with possible keys from
-  // printing/print_job_constants.h. Only used when printing without the system
-  // print dialog. E.g. for Print Preview. Returns false on error.
-  virtual bool UpdateSettings(const base::DictionaryValue& job_settings,
-                              const PageRanges& ranges,
+  // Updates the dialog to use |settings|. Only used when printing without the
+  // system print dialog. E.g. for Print Preview. Returns false on error.
+  // |pdf_only| is true if implementation needs to generate PDF without actual
+  // printing. In this case implementation may avoid setup of native print
+  // system. Ex. "save to pdf" or Cloud Print.
+  virtual bool UpdateSettings(bool target_is_pdf,
                               PrintSettings* settings) = 0;
 
   // Shows the dialog and handles the response with |callback|. Only used when