frames: apply modified hack from Mutter/Metacity

- this will be needed for proper window decoration color updates on theme change
  when theme variants fixes are applied

- realize/unrealize functions are dropped instead of map/unmap ones, because
  we didn't change these during GTK+3 porting

- MetaFrames now has GtkWindow as parent instead of GtkInvisible, otherwise
  the hack doesn't work (revert part of 96c7256d638b8c76c8abf786ba307e82a595dd67)

adapted from:
https://github.com/GNOME/metacity/commit/ba8500663457ad9f18ebfdf405162c2cb5caf88f

1 files changed, 2 insertions, 2 deletions

diff --git a/src/ui/frames.h b/src/ui/frames.h
index f1258783..ad86ee44 100644
--- a/src/ui/frames.h
+++ b/src/ui/frames.h
@@ -90,7 +90,7 @@ struct _MetaUIFrame
 
 struct _MetaFrames
 {
-  GtkInvisible parent_instance;
+  GtkWindow parent_instance;
 
   GHashTable *text_heights;
 
@@ -110,7 +110,7 @@ struct _MetaFrames
 
 struct _MetaFramesClass
 {
-  GtkInvisibleClass parent_class;
+  GtkWindowClass parent_class;
 };
 
 GType        meta_frames_get_type               (void) G_GNUC_CONST;