views: Make view::Views::GetPreferredSize() const.

ash/shelf/shelf_view.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_SHELF_SHELF_VIEW_H_
 #define ASH_SHELF_SHELF_VIEW_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 223 matching lines @@
   // Invoked after the fading out animation for item deletion is ended.
   void OnFadeOutAnimationEnded();
 
   // Fade in last visible item.
   void StartFadeInLastVisibleItem();
 
   // Updates the visible range of overflow items in |overflow_view|.
   void UpdateOverflowRange(ShelfView* overflow_view);
 
   // Overridden from views::View:
-  virtual gfx::Size GetPreferredSize() OVERRIDE;
+  virtual gfx::Size GetPreferredSize() const OVERRIDE;
   virtual void OnBoundsChanged(const gfx::Rect& previous_bounds) OVERRIDE;
   virtual FocusTraversable* GetPaneFocusTraversable() OVERRIDE;
   virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
 
   // Overridden from ui::EventHandler:
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
   // Overridden from ShelfModelObserver:
   virtual void ShelfItemAdded(int model_index) OVERRIDE;
   virtual void ShelfItemRemoved(int model_index, ShelfID id) OVERRIDE;
@@ skipping 178 matching lines @@
 
   // True when ripped item from overflow bubble is entered into Shelf.
   bool dragged_off_from_overflow_to_shelf_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_VIEW_H_