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

ash/shelf/shelf_view.h

Index: ash/shelf/shelf_view.h
diff --git a/ash/shelf/shelf_view.h b/ash/shelf/shelf_view.h
index 9f7c2ddf7c1a7f0516bbc34e4da94ff80ce8340e..d909d9160d5ab4371437984c07cb0f4c59e6e7c7 100644
--- a/ash/shelf/shelf_view.h
+++ b/ash/shelf/shelf_view.h
@@ -169,7 +169,7 @@ class ASH_EXPORT ShelfView : public views::View,
 
   // Calculates the ideal bounds. The bounds of each button corresponding to an
   // item in the model is set in |view_model_|.
-  void CalculateIdealBounds(IdealBounds* bounds);
+  void CalculateIdealBounds(IdealBounds* bounds) const;
 
   // Returns the index of the last view whose max primary axis coordinate is
   // less than |max_value|. Returns -1 if nothing fits, or there are no views.
@@ -203,7 +203,7 @@ class ASH_EXPORT ShelfView : public views::View,
   void FinalizeRipOffDrag(bool cancel);
 
   // Check if an item can be ripped off or not.
-  RemovableState RemovableByRipOff(int index);
+  RemovableState RemovableByRipOff(int index) const;
 
   // Returns true if |typea| and |typeb| should be in the same drag range.
   bool SameDragType(ShelfItemType typea, ShelfItemType typeb) const;
@@ -238,10 +238,10 @@ class ASH_EXPORT ShelfView : public views::View,
   void StartFadeInLastVisibleItem();
 
   // Updates the visible range of overflow items in |overflow_view|.
-  void UpdateOverflowRange(ShelfView* overflow_view);
+  void UpdateOverflowRange(ShelfView* overflow_view) const;
 
   // 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;
@@ -334,7 +334,7 @@ class ASH_EXPORT ShelfView : public views::View,
 
   // Last index of a launcher button that is visible
   // (does not go into overflow).
-  int last_visible_index_;
+  mutable int last_visible_index_;
 
   scoped_ptr<views::BoundsAnimator> bounds_animator_;
 
@@ -380,7 +380,7 @@ class ASH_EXPORT ShelfView : public views::View,
 
   // Index of the last hidden launcher item. If there are no hidden items this
   // will be equal to last_visible_index_ + 1.
-  int last_hidden_index_;
+  mutable int last_hidden_index_;
 
   // The timestamp of the event which closed the last menu - or 0.
   base::TimeDelta closing_event_time_;