[Cleanup] Screen cleanup

ash/shell.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_SHELL_H_
 #define ASH_SHELL_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 395 matching lines @@
   }
 
   aura::client::ActivationClient* activation_client() {
     return activation_client_;
   }
 
   ShelfItemDelegateManager* shelf_item_delegate_manager() {
     return shelf_item_delegate_manager_.get();
   }
 
-  ScreenAsh* screen() { return screen_; }
-
   // Force the shelf to query for it's current visibility state.
   void UpdateShelfVisibility();
 
   // TODO(oshima): Define an interface to access shelf/launcher
   // state, or just use Launcher.
 
   // Sets/gets the shelf auto-hide behavior on |root_window|.
   void SetShelfAutoHideBehavior(ShelfAutoHideBehavior behavior,
                                 aura::Window* root_window);
   ShelfAutoHideBehavior GetShelfAutoHideBehavior(
@@ skipping 143 matching lines @@
   // Overridden from aura::client::ActivationChangeObserver:
   virtual void OnWindowActivated(aura::Window* gained_active,
                                  aura::Window* lost_active) OVERRIDE;
 
   static Shell* instance_;
 
   // If set before the Shell is initialized, the mouse cursor will be hidden
   // when the screen is initially created.
   static bool initially_hide_cursor_;
 
-  ScreenAsh* screen_;
-
   // When no explicit target display/RootWindow is given, new windows are
   // created on |scoped_target_root_window_| , unless NULL in
   // which case they are created on |target_root_window_|.
   // |target_root_window_| never becomes NULL during the session.
   aura::Window* target_root_window_;
   aura::Window* scoped_target_root_window_;
 
   // The CompoundEventFilter owned by aura::Env object.
   scoped_ptr<views::corewm::CompoundEventFilter> env_filter_;
 
@@ skipping 113 matching lines @@
   bool simulate_modal_window_open_for_testing_;
 
   bool is_touch_hud_projection_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_