[gnome-flashback] screenshot: set rubberband css class in setup_window

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 460fb5436b587c3271675bac46ec76d0d928a685
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Oct 26 11:58:45 2019 +0300

    screenshot: set rubberband css class in setup_window
    
    Otherwise GTK will think that window is opaque.

 gnome-flashback/libscreenshot/gf-select-area.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/gnome-flashback/libscreenshot/gf-select-area.c b/gnome-flashback/libscreenshot/gf-select-area.c
index 494e590..d72b052 100644
--- a/gnome-flashback/libscreenshot/gf-select-area.c
+++ b/gnome-flashback/libscreenshot/gf-select-area.c
@@ -66,14 +66,9 @@ draw_cb (GtkWidget *widget,
   width = gtk_widget_get_allocated_width (widget);
   height = gtk_widget_get_allocated_height (widget);
 
-  gtk_style_context_save (context);
-  gtk_style_context_add_class (context, GTK_STYLE_CLASS_RUBBERBAND);
-
   gtk_render_background (context, cr, 0, 0, width, height);
   gtk_render_frame (context, cr, 0, 0, width, height);
 
-  gtk_style_context_restore (context);
-
   return TRUE;
 }
 
@@ -213,8 +208,13 @@ setup_window (GfSelectArea *select_area)
 
   if (gdk_screen_is_composited (screen) && visual != NULL)
     {
+      GtkStyleContext *context;
+
       gtk_widget_set_visual (select_area->window, visual);
       select_area->composited = TRUE;
+
+      context = gtk_widget_get_style_context (select_area->window);
+      gtk_style_context_add_class (context, GTK_STYLE_CLASS_RUBBERBAND);
     }
 
   g_signal_connect (select_area->window, "draw",