[gtk+] Set a bg on GtkViewport to ensure we get fast scrolling

[Alexander Larsson <alexl src gnome org>]

commit 4b200a04294e445af6083924c9796d6467a41187
Author: Alexander Larsson <alexl redhat com>
Date:   Tue Feb 14 15:14:37 2012 +0100

    Set a bg on GtkViewport to ensure we get fast scrolling
    
    Otherwise it will use the default alpha transparency and
    not scroll efficiently.

 gtk/gtk-win32.css |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtk-win32.css b/gtk/gtk-win32.css
index c27fd23..f0349a0 100644
--- a/gtk/gtk-win32.css
+++ b/gtk/gtk-win32.css
@@ -12,7 +12,8 @@
 @define-color error_fg_color rgb (166, 38, 38);
 @define-color error_bg_color rgb (237, 54, 54);
 
-GtkWindow {
+GtkWindow,
+GtkViewport {
     background-color: @bg_color;
 }