Remove old (dead) app list code.

ash/app_list/app_list_presenter_delegate.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 ASH_APP_LIST_APP_LIST_PRESENTER_DELEGATE_H_
 #define ASH_APP_LIST_APP_LIST_PRESENTER_DELEGATE_H_
 
 #include <stdint.h>
 
 #include "ash/ash_export.h"
@@ skipping 54 matching lines @@
 
   // ui::EventHandler overrides:
   void OnMouseEvent(ui::MouseEvent* event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
 
   // KeyboardControllerObserver overrides:
   void OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) override;
   void OnKeyboardClosed() override;
 
   // ShellObserver overrides:
-  void OnShelfAlignmentChanged(WmWindow* root_window) override;
   void OnOverviewModeStarting() override;
   void OnMaximizeModeStarted() override;
   void OnMaximizeModeEnded() override;
 
   // WmShelfObserver overrides:
   void OnShelfIconPositionsChanged() override;
 
   // Whether the app list is visible (or in the process of being shown).
   bool is_visible_ = false;
 
-  // Whether the app list should remain centered.
-  bool is_centered_ = false;
-
   // Not owned. Pointer is guaranteed to be valid while this object is alive.
   app_list::AppListPresenter* presenter_;
 
   // Not owned. Pointer is guaranteed to be valid while this object is alive.
   app_list::AppListViewDelegateFactory* view_delegate_factory_;
 
   // Owned by its widget.
   app_list::AppListView* view_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(AppListPresenterDelegate);
 };
 
 }  // namespace ash
 
 #endif  // ASH_APP_LIST_APP_LIST_PRESENTER_DELEGATE_H_