GTK: More raw struct access removal, this time focusing on GtkDialog.

chrome/browser/ui/gtk/bookmarks/bookmark_editor_gtk.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/gtk/bookmarks/bookmark_editor_gtk.h"
 
 #include <gtk/gtk.h>
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 293 matching lines @@
       parent_window,
       GTK_DIALOG_MODAL,
       GTK_STOCK_CANCEL, GTK_RESPONSE_REJECT,
       GTK_STOCK_SAVE, GTK_RESPONSE_ACCEPT,
       NULL);
 #if !GTK_CHECK_VERSION(2, 22, 0)
   gtk_dialog_set_has_separator(GTK_DIALOG(dialog_), FALSE);
 #endif
 
   if (show_tree_) {
-    GtkWidget* action_area = GTK_DIALOG(dialog_)->action_area;
+    GtkWidget* action_area = gtk_dialog_get_action_area(GTK_DIALOG(dialog_));
     new_folder_button_ = gtk_button_new_with_label(
         l10n_util::GetStringUTF8(
             IDS_BOOKMARK_EDITOR_NEW_FOLDER_BUTTON).c_str());
     g_signal_connect(new_folder_button_, "clicked",
                      G_CALLBACK(OnNewFolderClickedThunk), this);
     gtk_container_add(GTK_CONTAINER(action_area), new_folder_button_);
     gtk_button_box_set_child_secondary(GTK_BUTTON_BOX(action_area),
                                        new_folder_button_, TRUE);
   }
 
@@ skipping 360 matching lines @@
       GTK_TREE_MODEL(tree_store_), &new_item_iter);
   gtk_tree_view_expand_to_path(GTK_TREE_VIEW(tree_view_), path);
 
   // Make the folder name editable.
   gtk_tree_view_set_cursor(GTK_TREE_VIEW(tree_view_), path,
       gtk_tree_view_get_column(GTK_TREE_VIEW(tree_view_), 0),
       TRUE);
 
   gtk_tree_path_free(path);
 }