GTK: implement "print selection".

chrome/browser/printing/print_dialog_gtk.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 CHROME_BROWSER_PRINTING_PRINT_DIALOG_GTK_H_
 #define CHROME_BROWSER_PRINTING_PRINT_DIALOG_GTK_H_
 #pragma once
 
 #include <gtk/gtk.h>
 #include <gtk/gtkunixprint.h>
@@ skipping 24 matching lines @@
   // Creates and returns a print dialog.
   static printing::PrintDialogGtkInterface* CreatePrintDialog(
       PrintingContextGtk* context);
 
   // printing::PrintDialogGtkInterface implementation.
   virtual void UseDefaultSettings() OVERRIDE;
   virtual bool UpdateSettings(const base::DictionaryValue& job_settings,
                               const printing::PageRanges& ranges,
                               printing::PrintSettings* settings) OVERRIDE;
   virtual void ShowDialog(
+      bool has_selection,
       const PrintingContextGtk::PrintSettingsCallback& callback) OVERRIDE;
   virtual void PrintDocument(const printing::Metafile* metafile,
                              const string16& document_name) OVERRIDE;
   virtual void AddRefToDialog() OVERRIDE;
   virtual void ReleaseDialog() OVERRIDE;
 
  private:
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::UI>;
   friend class base::DeleteHelper<PrintDialogGtk>;
@@ skipping 28 matching lines @@
   GtkPrintSettings* gtk_settings_;
   GtkPageSetup* page_setup_;
   GtkPrinter* printer_;
 
   FilePath path_to_pdf_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintDialogGtk);
 };
 
 #endif  // CHROME_BROWSER_PRINTING_PRINT_DIALOG_GTK_H_