xvimagesink: don't paint the window black when going to NULL

Leave dealing with the appearance of the window when we are not playing to the
applications. We anyway want to go to NULL as quickly as possible.

Fixes #635800

sys/xvimage/xvimagesink.c

 /* GStreamer
  * Copyright (C) <2005> Julien Moutte <julien@moutte.net>
- *               <2009>,<2010> Stefan Kost <stefan.kost@nokia.com> 
+ *               <2009>,<2010> Stefan Kost <stefan.kost@nokia.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -1085,13 +1085,6 @@ gst_xvimagesink_xwindow_clear (GstXvImageSink * xvimagesink,
   XvStopVideo (xvimagesink->xcontext->disp, xvimagesink->xcontext->xv_port_id,
       xwindow->win);
 
-  XSetForeground (xvimagesink->xcontext->disp, xwindow->gc,
-      xvimagesink->xcontext->black);
-
-  XFillRectangle (xvimagesink->xcontext->disp, xwindow->win, xwindow->gc,
-      xvimagesink->render_rect.x, xvimagesink->render_rect.y,
-      xvimagesink->render_rect.w, xvimagesink->render_rect.h);
-
   XSync (xvimagesink->xcontext->disp, FALSE);
 
   g_mutex_unlock (xvimagesink->x_lock);
@@ -1879,7 +1872,7 @@ gst_xvimagesink_xcontext_get (GstXvImageSink * xvimagesink)
   for (i = 0; i < (sizeof (channels) / sizeof (char *)); i++) {
     XvAttribute *matching_attr = NULL;
 
-    /* Retrieve the property atom if it exists. If it doesn't exist, 
+    /* Retrieve the property atom if it exists. If it doesn't exist,
      * the attribute itself must not either, so we can skip */
     prop_atom = XInternAtom (xcontext->disp, channels[i], True);
     if (prop_atom == None)
@@ -2206,7 +2199,7 @@ gst_xvimagesink_setcaps (GstBaseSink * bsink, GstCaps * caps)
         GST_VIDEO_SINK_HEIGHT (xvimagesink));
   }
 
-  /* After a resize, we want to redraw the borders in case the new frame size 
+  /* After a resize, we want to redraw the borders in case the new frame size
    * doesn't cover the same area */
   xvimagesink->redraw_border = TRUE;