[gtk+] Mention cairo_save/restore in the ::draw migration docs

[Matthias Clasen <matthiasc src gnome org>]

commit d7550bb8fb9dbc380b3c5898290c0c61a944345d
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat May 26 13:45:06 2012 -0400

    Mention cairo_save/restore in the ::draw migration docs
    
    https://bugzilla.gnome.org/show_bug.cgi?id=646798

 docs/reference/gtk/migrating-2to3.xml |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/docs/reference/gtk/migrating-2to3.xml b/docs/reference/gtk/migrating-2to3.xml
index 33d2275..9db760a 100644
--- a/docs/reference/gtk/migrating-2to3.xml
+++ b/docs/reference/gtk/migrating-2to3.xml
@@ -1001,7 +1001,8 @@ AM_CONDITIONAL(BUILD_x11, [test "x$have_x11" = "xyes"])
       Another convenience function that can help when implementing
       ::draw for multi-window widgets is gtk_cairo_transform_to_window(),
       which transforms a cairo context from widget-relative coordinates
-      to window-relative coordinates.
+      to window-relative coordinates. You may want to use cairo_save() and
+      cairo_restore() when modifying the cairo context in your draw function.
     </para>
     <para>
       All GtkStyle drawing functions (gtk_paint_box(), etc) have been changed