[gnome-control-center] display: Fix coordinate calculations

[Matthias Clasen <matthiasc src gnome org>]

commit a61f0654b98357283ef68bea6d827aabc0a2779e
Author: Benjamin Berg <benjamin sipsolutions net>
Date:   Sun Sep 16 17:09:45 2012 -0400

    display: Fix coordinate calculations
    
    https://bugzilla.gnome.org/show_bug.cgi?id=681475

 panels/display/scrollarea.c |   11 ++---------
 1 files changed, 2 insertions(+), 9 deletions(-)
---
diff --git a/panels/display/scrollarea.c b/panels/display/scrollarea.c
index d705f02..995872d 100644
--- a/panels/display/scrollarea.c
+++ b/panels/display/scrollarea.c
@@ -1194,17 +1194,10 @@ user_to_device (double *x, double *y,
   gdouble ox, oy;
   user_to_device_data* data = user_data;
 
-  /* Required in case the user does transformations (eg. translates) */
+  /* The translations by the user */
   cairo_user_to_device (data->cr, x, y);
 
-  /* The device offset is different for a full redraw.
-   * So we cannot make assumptions about it. */
-  cairo_surface_get_device_offset(cairo_get_target(data->cr), &ox, &oy);
-
-  *x -= ox;
-  *y -= oy;
-
-  /* The input_window does not of the allocation offset. */
+  /* The position of the widget on the window. */
   *x -= data->allocation.x;
   *y -= data->allocation.y;
 }