GUI2/Window: removed restore flag and restorer surface

src/gui/widgets/window.cpp

@@ -315,9 +315,7 @@ window::window(CVideo& video,
 	, variables_()
 	, invalidate_layout_blocked_(false)
 	, suspend_drawing_(true)
-	, restore_(true)
 	, is_toplevel_(!is_in_dialog())
-	, restorer_()
 	, automatic_placement_(automatic_placement)
 	, horizontal_placement_(horizontal_placement)
 	, vertical_placement_(vertical_placement)

src/gui/widgets/window.hpp

@@ -527,15 +527,9 @@ class window : public panel, public cursor::setter
 	/** Avoid drawing the window.  */
 	bool suspend_drawing_;
 
-	/** Whether the window should undraw the window using restorer_ */
-	bool restore_;
-
 	/** Whether the window has other windows behind it */
 	bool is_toplevel_;
 
-	/** When the window closes this surface is used to undraw the window. */
-	surface restorer_;
-
 	/** Do we wish to place the widget automatically? */
 	const bool automatic_placement_;