Add a ListModel::Move.

ui/app_list/apps_grid_view.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 "ui/app_list/apps_grid_view.h"
 
 #include <algorithm>
 
 #include "ui/app_list/app_list_item_view.h"
 #include "ui/app_list/pagination_model.h"
@@ skipping 305 matching lines @@
 void AppsGridView::ListItemsRemoved(size_t start, size_t count) {
   for (size_t i = 0; i < count; ++i)
     delete child_at(start);
 
   UpdatePaginationModel();
 
   Layout();
   SchedulePaint();
 }
 
+void AppsGridView::ListItemMoved(size_t index, size_t target_index) {
+  NOTREACHED();
+}
+
 void AppsGridView::ListItemsChanged(size_t start, size_t count) {
   NOTREACHED();
 }
 
 void AppsGridView::TotalPagesChanged() {
 }
 
 void AppsGridView::SelectedPageChanged(int old_selected, int new_selected) {
   Layout();
 }
 
 void AppsGridView::TransitionChanged() {
   // Update layout for valid page transition only since over-scroll no longer
   // animates app icons.
   const PaginationModel::Transition& transition =
       pagination_model_->transition();
   if (pagination_model_->is_valid_page(transition.target_page))
     Layout();
 }
 
 }  // namespace app_list