Sets transient for PrintDialogGtk2

chrome/browser/ui/libgtk2ui/print_dialog_gtk2.h

 // Copyright 2014 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_UI_LIBGTK2UI_PRINT_DIALOG_GTK2_H_
 #define CHROME_BROWSER_UI_LIBGTK2UI_PRINT_DIALOG_GTK2_H_
 
 #include <gtk/gtk.h>
 #include <gtk/gtkunixprint.h>
 
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "chrome/browser/ui/libgtk2ui/gtk2_signal.h"
 #include "content/public/browser/browser_thread.h"
 #include "printing/print_dialog_gtk_interface.h"
 #include "printing/printing_context_linux.h"
+#include "ui/aura/window_observer.h"
 
 namespace printing {
 class Metafile;
 class PrintSettings;
 }
 
 using printing::PrintingContextLinux;
 
 // Needs to be freed on the UI thread to clean up its GTK members variables.
 class PrintDialogGtk2
     : public printing::PrintDialogGtkInterface,
       public base::RefCountedThreadSafe<
-          PrintDialogGtk2, content::BrowserThread::DeleteOnUIThread> {
+          PrintDialogGtk2, content::BrowserThread::DeleteOnUIThread>,
+      public aura::WindowObserver {
  public:
   // Creates and returns a print dialog.
   static printing::PrintDialogGtkInterface* CreatePrintDialog(
       PrintingContextLinux* context);
 
   // printing::PrintDialogGtkInterface implementation.
   virtual void UseDefaultSettings() OVERRIDE;
   virtual bool UpdateSettings(printing::PrintSettings* settings) OVERRIDE;
   virtual void ShowDialog(
       gfx::NativeView parent_view,
@@ skipping 21 matching lines @@
   // Handles print job response.
   static void OnJobCompletedThunk(GtkPrintJob* print_job,
                                   gpointer user_data,
                                   GError* error);
   void OnJobCompleted(GtkPrintJob* print_job, GError* error);
 
   // Helper function for initializing |context_|'s PrintSettings with a given
   // |settings|.
   void InitPrintSettings(printing::PrintSettings* settings);
 
+  // aura::WindowObserver implementation.
+  virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
+
   // Printing dialog callback.
   PrintingContextLinux::PrintSettingsCallback callback_;
   PrintingContextLinux* context_;
 
   // Print dialog settings. PrintDialogGtk2 owns |dialog_| and holds references
   // to the other objects.
   GtkWidget* dialog_;
   GtkPrintSettings* gtk_settings_;
   GtkPageSetup* page_setup_;
   GtkPrinter* printer_;
 
   base::FilePath path_to_pdf_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintDialogGtk2);
 };
 
 #endif  // CHROME_BROWSER_UI_LIBGTK2UI_PRINT_DIALOG_GTK2_H_