ui/base/models: Add empty() accessor to TreeNode class.

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

 // 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.
 
 #include "chrome/browser/ui/gtk/bookmarks/bookmark_menu_controller_gtk.h"
 
 #include <gtk/gtk.h>
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 179 matching lines @@
     // not the handler that the drag source uses.
     if (node->is_folder()) {
       signals_.Connect(menu_item, "button-press-event",
                        G_CALLBACK(OnFolderButtonPressedThunk), this);
     }
 
     gtk_menu_shell_append(GTK_MENU_SHELL(menu), menu_item);
     node_to_menu_widget_map_[node] = menu_item;
   }
 
-  if (parent->child_count() == 0) {
+  if (parent->empty()) {
     GtkWidget* empty_menu = gtk_menu_item_new_with_label(
         l10n_util::GetStringUTF8(IDS_MENU_EMPTY_SUBMENU).c_str());
     gtk_widget_set_sensitive(empty_menu, FALSE);
     g_object_set_data(G_OBJECT(menu), "parent-node", AsVoid(parent));
     gtk_menu_shell_append(GTK_MENU_SHELL(menu), empty_menu);
   }
 }
 
 gboolean BookmarkMenuController::OnMenuButtonPressedOrReleased(
     GtkWidget* sender,
@@ skipping 152 matching lines @@
 }
 
 void BookmarkMenuController::OnMenuItemDragGet(
     GtkWidget* widget, GdkDragContext* context,
     GtkSelectionData* selection_data,
     guint target_type, guint time) {
   const BookmarkNode* node = bookmark_utils::BookmarkNodeForWidget(widget);
   bookmark_utils::WriteBookmarkToSelection(node, selection_data, target_type,
                                            profile_);
 }