native: Make gtk_native_get_surface_transform public

This api is needed to translate between surface
and widget coordinates.

docs/reference/gtk/gtk4-sections.txt

@@ -6617,6 +6617,7 @@ gtk_native_get_for_surface
 gtk_native_get_surface
 gtk_native_get_renderer
 gtk_native_check_resize
+gtk_native_get_surface_transform
 
 <SUBSECTION Private>
 gtk_native_get_type

gtk/gtknative.h

@@ -67,6 +67,11 @@ GdkSurface *gtk_native_get_surface     (GtkNative *self);
 GDK_AVAILABLE_IN_ALL
 GskRenderer *gtk_native_get_renderer   (GtkNative *self);
 
+GDK_AVAILABLE_IN_ALL
+void         gtk_native_get_surface_transform (GtkNative *self,
+                                               int       *x,
+                                               int       *y);
+
 G_END_DECLS
 
 #endif /* __GTK_NATIVE_H__ */

gtk/gtknativeprivate.h

@@ -5,10 +5,6 @@
 
 G_BEGIN_DECLS
 
-void          gtk_native_get_surface_transform (GtkNative *self,
-                                                int       *x,
-                                                int       *y);
-
 G_END_DECLS
 
 #endif /* __GTK_NATIVE_PRIVATE_H__ */