De-virtualize BView::InvalidateLayout() and introduce LayoutInvalidated() hook, like BLayout.

headers/os/interface/CheckBox.h

@@ -52,8 +52,6 @@ public:
 									float* _height);
 	virtual	void				ResizeToPreferred();
 
-	virtual	void				InvalidateLayout(bool descendants = false);
-
 	virtual	BSize				MinSize();
 	virtual	BSize				MaxSize();
 	virtual	BSize				PreferredSize();
@@ -70,6 +68,9 @@ public:
 
 	virtual	status_t			Perform(perform_code code, void* data);
 
+protected:
+	virtual	void				LayoutInvalidated(bool descendants = false);
+
 private:
 	// FBC padding
 	virtual	void				_ReservedCheckBox1();