aura: Implement app list M19 mock.

ash/app_list/app_list_item_group_model.cc

Index: ash/app_list/app_list_item_group_model.cc
diff --git a/ash/app_list/app_list_item_group_model.cc b/ash/app_list/app_list_item_group_model.cc
deleted file mode 100644
index c2fce3ad44844b9453e062aa12f9bc14b7d7ebda..0000000000000000000000000000000000000000
--- a/ash/app_list/app_list_item_group_model.cc
+++ /dev/null
@@ -1,25 +0,0 @@
-// 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 "ash/app_list/app_list_item_group_model.h"
-
-namespace ash {
-
-AppListItemGroupModel::AppListItemGroupModel(const std::string& title)
-    : title_(title) {
-}
-
-AppListItemGroupModel::~AppListItemGroupModel() {
-}
-
-void AppListItemGroupModel::AddItem(AppListItemModel* item) {
-  items_.Add(item);
-}
-
-AppListItemModel* AppListItemGroupModel::GetItem(int index) {
-  DCHECK(index >= 0 && index < item_count());
-  return items_.item_at(index);
-}
-
-}  // namespace ash