ui/base/models: Make ComboboxModel::GetItemCount() a constant function.

chrome/browser/bookmarks/recently_used_folders_combo_model.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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/bookmarks/recently_used_folders_combo_model.h"
 
 #include "chrome/browser/bookmarks/bookmark_utils.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
 namespace {
@@ skipping 35 matching lines @@
     nodes_.push_back(model->mobile_node());
 
   std::vector<const BookmarkNode*>::iterator it = std::find(nodes_.begin(),
                                                             nodes_.end(),
                                                             node->parent());
   node_parent_index_ = static_cast<int>(it - nodes_.begin());
 }
 
 RecentlyUsedFoldersComboModel::~RecentlyUsedFoldersComboModel() {}
 
-int RecentlyUsedFoldersComboModel::GetItemCount() {
+int RecentlyUsedFoldersComboModel::GetItemCount() const {
   return static_cast<int>(nodes_.size() + 1);
 }
 
 string16 RecentlyUsedFoldersComboModel::GetItemAt(int index) {
   if (index == static_cast<int>(nodes_.size()))
     return
        l10n_util::GetStringUTF16(IDS_BOOKMARK_BUBBLE_CHOOSER_ANOTHER_FOLDER);
   return nodes_[index]->GetTitle();
 }
 
 const BookmarkNode* RecentlyUsedFoldersComboModel::GetNodeAt(int index) {
   if (index < 0 || index >= static_cast<int>(nodes_.size()))
     return NULL;
   return nodes_[index];
 }
 
 void RecentlyUsedFoldersComboModel::RemoveNode(const BookmarkNode* node) {
   std::vector<const BookmarkNode*>::iterator it = std::find(nodes_.begin(),
                                                             nodes_.end(),
                                                             node);
   if (it != nodes_.end())
     nodes_.erase(it);
 }