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

chrome/browser/ui/views/bookmarks/bookmark_bar_view.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/views/bookmarks/bookmark_bar_view.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <vector>
@@ skipping 1603 matching lines @@
   if (!theme_provider)
     return;
   SkColor text_color =
       theme_provider->GetColor(ThemeService::COLOR_BOOKMARK_TEXT);
   for (int i = 0; i < GetBookmarkButtonCount(); ++i)
     GetBookmarkButton(i)->SetEnabledColor(text_color);
   other_bookmarked_button()->SetEnabledColor(text_color);
 }
 
 void BookmarkBarView::UpdateOtherBookmarksVisibility() {
-  bool has_other_children = model_->other_node()->child_count() > 0;
+  bool has_other_children = !model_->other_node()->empty();
   if (has_other_children == other_bookmarked_button_->IsVisible())
     return;
   other_bookmarked_button_->SetVisible(has_other_children);
   bookmarks_separator_view_->SetVisible(has_other_children);
   Layout();
   SchedulePaint();
 }
 
 gfx::Size BookmarkBarView::LayoutItems(bool compute_bounds_only) {
   gfx::Size prefsize;
@@ skipping 138 matching lines @@
               (1 - size_animation_->GetCurrentValue())));
     } else {
       prefsize.set_height(
           static_cast<int>(
               browser_defaults::kBookmarkBarHeight *
               size_animation_->GetCurrentValue()));
     }
   }
   return prefsize;
 }