[gtk+/wip/baedert/drawing] drawingarea: Remove useless line from code example

[Timm Bäder <baedert src gnome org>]

commit 6e1481d7ac6eb63c98b006db278d8902987fc109
Author: Timm Bäder <mail baedert org>
Date:   Wed Jun 28 11:17:03 2017 +0200

    drawingarea: Remove useless line from code example
    
    backgrounds are drawn automatically now.

 gtk/gtkdrawingarea.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtkdrawingarea.c b/gtk/gtkdrawingarea.c
index cc2c94a..12d46e7 100644
--- a/gtk/gtkdrawingarea.c
+++ b/gtk/gtkdrawingarea.c
@@ -80,8 +80,7 @@ static GParamSpec *props[LAST_PROP] = { NULL, };
  *
  * Note that GDK automatically clears the exposed area before causing a
  * redraw, and that drawing is implicitly clipped to the exposed
- * area. If you want to have a theme-provided background, you need
- * to call gtk_render_background() in your ::draw method.
+ * area.
  *
  * ## Simple GtkDrawingArea usage
  *
@@ -96,8 +95,6 @@ static GParamSpec *props[LAST_PROP] = { NULL, };
  *
  *   context = gtk_widget_get_style_context (GTK_WIDGET (area));
  *
- *   gtk_render_background (context, cr, 0, 0, width, height);
- *
  *   cairo_arc (cr,
  *              width / 2.0, height / 2.0,
  *              MIN (width, height) / 2.0,