Add a ListModel::Move.

ui/app_list/apps_grid_view.h

 // 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.
 
 #ifndef UI_APP_LIST_APPS_GRID_VIEW_H_
 #define UI_APP_LIST_APPS_GRID_VIEW_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/app_list/app_list_export.h"
@@ skipping 55 matching lines @@
   void UpdatePaginationModel();
 
   AppListItemView* CreateViewForItemAtIndex(size_t index);
 
   AppListItemView* GetItemViewAtIndex(int index);
   void SetSelectedItemByIndex(int index);
 
   // Overridden from ListModelObserver:
   virtual void ListItemsAdded(size_t start, size_t count) OVERRIDE;
   virtual void ListItemsRemoved(size_t start, size_t count) OVERRIDE;
+  virtual void ListItemMoved(size_t index, size_t target_index) OVERRIDE;
   virtual void ListItemsChanged(size_t start, size_t count) OVERRIDE;
 
   // Overridden from PaginationModelObserver:
   virtual void TotalPagesChanged() OVERRIDE;
   virtual void SelectedPageChanged(int old_selected, int new_selected) OVERRIDE;
   virtual void TransitionChanged() OVERRIDE;
 
   AppListModel::Apps* model_;  // Owned by AppListModel.
   views::ButtonListener* listener_;
   PaginationModel* pagination_model_;  // Owned by AppListController.
 
   gfx::Size icon_size_;
   int cols_;
   int rows_per_page_;
 
   int selected_item_index_;
 
   DISALLOW_COPY_AND_ASSIGN(AppsGridView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_APPS_GRID_VIEW_H_