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

ui/views/controls/menu/submenu_view.h

Index: ui/views/controls/menu/submenu_view.h
diff --git a/ui/views/controls/menu/submenu_view.h b/ui/views/controls/menu/submenu_view.h
index 6cfefad9f668c5a432a18cdcb9ad29a9cf2069e0..1b7d36243d2bcbf035366f68bd385e53acb49047 100644
--- a/ui/views/controls/menu/submenu_view.h
+++ b/ui/views/controls/menu/submenu_view.h
@@ -55,7 +55,7 @@ class VIEWS_EXPORT SubmenuView : public PrefixDelegate,
   // Positions and sizes the child views. This tiles the views vertically,
   // giving each child the available width.
   virtual void Layout() OVERRIDE;
-  virtual gfx::Size GetPreferredSize() OVERRIDE;
+  virtual gfx::Size GetPreferredSize() const OVERRIDE;
 
   // Override from View.
   virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
@@ -201,7 +201,7 @@ class VIEWS_EXPORT SubmenuView : public PrefixDelegate,
   MenuScrollViewContainer* scroll_view_container_;
 
   // See description above getter.
-  int max_minor_text_width_;
+  mutable int max_minor_text_width_;
 
   // Minimum width returned in GetPreferredSize().
   int minimum_preferred_width_;