Revert 115515 - [Aura] Implement views-based applist.

ui/aura_shell/app_list/app_list_model.h

-// 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.
-
-#ifndef UI_AURA_SHELL_APP_LIST_APP_LIST_MODEL_H_
-#define UI_AURA_SHELL_APP_LIST_APP_LIST_MODEL_H_
-#pragma once
-
-#include "base/basictypes.h"
-#include "ui/aura_shell/app_list/app_list_item_group_model.h"
-#include "ui/aura_shell/aura_shell_export.h"
-#include "ui/base/models/list_model.h"
-
-namespace aura_shell {
-
-// Model for AppListView. It is consisted of a list of AppListItemGroupModels,
-// which in turn owns a list of AppListItemModels.
-class AURA_SHELL_EXPORT AppListModel {
- public:
-  AppListModel();
-  virtual ~AppListModel();
-
-  void AddGroup(AppListItemGroupModel* group);
-  AppListItemGroupModel* GetGroup(int index);
-
-  void AddObserver(ui::ListModelObserver* observer);
-  void RemoveObserver(ui::ListModelObserver* observer);
-
-  int group_count() const {
-    return groups_.item_count();
-  }
-
- private:
-  ui::ListModel<AppListItemGroupModel> groups_;
-
-  DISALLOW_COPY_AND_ASSIGN(AppListModel);
-};
-
-}  // namespace aura_shell
-
-#endif  // UI_AURA_SHELL_APP_LIST_APP_LIST_MODEL_H_