[libchamplain] Add comment about background pattern performance

[Jiří Techet <jiritechet src gnome org>]

commit 1e748b01b86b6790aff595ab5fb0ef7111f09e26
Author: Jiří Techet <techet gmail com>
Date:   Mon Apr 29 01:56:20 2013 +0200

    Add comment about background pattern performance

 champlain/champlain-view.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/champlain/champlain-view.c b/champlain/champlain-view.c
index 1fba45d..c9d05bc 100644
--- a/champlain/champlain-view.c
+++ b/champlain/champlain-view.c
@@ -2423,7 +2423,9 @@ champlain_view_ensure_layers_visible (ChamplainView *view,
  * @view: a #ChamplainView
  * @background: The background texture
  *
- * Sets the background texture displayed behind the map.
+ * Sets the background texture displayed behind the map. Setting the background
+ * pattern affects performence slightly - use reasonably large patterns for
+ * better performance.
  *
  * Since: 0.12.4
  */