views: Extract SystemMenuModel from native_menu_win.*.

ui/views/controls/menu/native_menu_win.h

Index: ui/views/controls/menu/native_menu_win.h
diff --git a/ui/views/controls/menu/native_menu_win.h b/ui/views/controls/menu/native_menu_win.h
index 08e07bade49e0fd0a79c1036591753bae7de4824..4b97f7e24bc085bae70607ade0e1421c4a9687d1 100644
--- a/ui/views/controls/menu/native_menu_win.h
+++ b/ui/views/controls/menu/native_menu_win.h
@@ -13,10 +13,14 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
-#include "ui/base/models/simple_menu_model.h"
+#include "base/string16.h"
 #include "ui/views/controls/menu/menu_wrapper.h"
 #include "ui/views/views_export.h"
 
+namespace ui {
+class MenuModel;
+}
+
 namespace views {
 
 // A Windows implementation of MenuWrapper.
@@ -161,24 +165,6 @@ class VIEWS_EXPORT NativeMenuWin : public MenuWrapper {
   DISALLOW_COPY_AND_ASSIGN(NativeMenuWin);
 };
 
-// A SimpleMenuModel subclass that allows the system menu for a window to be
-// wrapped.
-class VIEWS_EXPORT SystemMenuModel : public ui::SimpleMenuModel {
- public:
-  explicit SystemMenuModel(Delegate* delegate);
-  virtual ~SystemMenuModel();
-
-  // Overridden from ui::MenuModel:
-  virtual int GetFirstItemIndex(gfx::NativeMenu native_menu) const;
-
- protected:
-  // Overridden from SimpleMenuModel:
-  virtual int FlipIndex(int index) const { return GetItemCount() - index - 1; }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(SystemMenuModel);
-};
-
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_NATIVE_MENU_WIN_H_