Use mojo Shelf interfaces for both mash and classic ash.

ash/common/wm_shell.h

 // Copyright 2016 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_COMMON_WM_SHELL_H_
 #define ASH_COMMON_WM_SHELL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 42 matching lines @@
 class ImmersiveFullscreenController;
 class KeyEventWatcher;
 class KeyboardBrightnessControlDelegate;
 class KeyboardUI;
 class MaximizeModeController;
 class MruWindowTracker;
 class NewWindowDelegate;
 class PaletteDelegate;
 class ScopedDisableInternalMouseAndKeyboard;
 class SessionStateDelegate;
+class ShelfController;
 class ShelfDelegate;
 class ShelfModel;
 class ShelfWindowWatcher;
 class ShellDelegate;
 class ShellObserver;
 class SystemTrayDelegate;
 class SystemTrayController;
 class SystemTrayNotifier;
 class ToastManager;
 class WallpaperController;
@@ skipping 66 matching lines @@
     return new_window_delegate_.get();
   }
 
   // NOTE: Prefer ScopedRootWindowForNewWindows when setting temporarily.
   void set_root_window_for_new_windows(WmWindow* root) {
     root_window_for_new_windows_ = root;
   }
 
   PaletteDelegate* palette_delegate() { return palette_delegate_.get(); }
 
+  ShelfController* shelf_controller() { return shelf_controller_.get(); }
+
   ShelfDelegate* shelf_delegate() { return shelf_delegate_.get(); }
 
-  ShelfModel* shelf_model() { return shelf_model_.get(); }
+  ShelfModel* shelf_model();
 
   SystemTrayController* system_tray_controller() {
     return system_tray_controller_.get();
   }
 
   SystemTrayNotifier* system_tray_notifier() {
     return system_tray_notifier_.get();
   }
 
   SystemTrayDelegate* system_tray_delegate() {
@@ skipping 304 matching lines @@
   std::unique_ptr<FocusCycler> focus_cycler_;
   std::unique_ptr<ImmersiveContextAsh> immersive_context_;
   std::unique_ptr<KeyboardBrightnessControlDelegate>
       keyboard_brightness_control_delegate_;
   std::unique_ptr<KeyboardUI> keyboard_ui_;
   std::unique_ptr<MaximizeModeController> maximize_mode_controller_;
   std::unique_ptr<MediaDelegate> media_delegate_;
   std::unique_ptr<MruWindowTracker> mru_window_tracker_;
   std::unique_ptr<NewWindowDelegate> new_window_delegate_;
   std::unique_ptr<PaletteDelegate> palette_delegate_;
+  std::unique_ptr<ShelfController> shelf_controller_;
   std::unique_ptr<ShelfDelegate> shelf_delegate_;
-  std::unique_ptr<ShelfModel> shelf_model_;
   std::unique_ptr<ShelfWindowWatcher> shelf_window_watcher_;
   std::unique_ptr<SystemTrayController> system_tray_controller_;
   std::unique_ptr<SystemTrayNotifier> system_tray_notifier_;
   std::unique_ptr<SystemTrayDelegate> system_tray_delegate_;
   std::unique_ptr<ToastManager> toast_manager_;
   std::unique_ptr<WallpaperController> wallpaper_controller_;
   std::unique_ptr<WallpaperDelegate> wallpaper_delegate_;
   std::unique_ptr<WindowCycleController> window_cycle_controller_;
   std::unique_ptr<WindowSelectorController> window_selector_controller_;
 
   base::ObserverList<LockStateObserver> lock_state_observers_;
 
   // See comment for GetRootWindowForNewWindows().
   WmWindow* root_window_for_new_windows_ = nullptr;
   WmWindow* scoped_root_window_for_new_windows_ = nullptr;
 
   bool simulate_modal_window_open_for_testing_ = false;
 
   scoped_refptr<base::SequencedWorkerPool> blocking_pool_;
 
 #if defined(OS_CHROMEOS)
   std::unique_ptr<LogoutConfirmationController> logout_confirmation_controller_;
 #endif
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_SHELL_H_