libvpx: Pull from upstream

source/libvpx/vp9/decoder/vp9_decoder.c

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 250 matching lines @@
     if (cm->new_fb_idx > 0 && cm->frame_bufs[cm->new_fb_idx].ref_count > 0)
       cm->frame_bufs[cm->new_fb_idx].ref_count--;
 
     return -1;
   }
 
   cm->error.setjmp = 1;
 
   vp9_decode_frame(pbi, source, source + size, psource);
 
-  if (!cm->show_existing_frame)
-    swap_frame_buffers(pbi);
-  else
-    cm->frame_to_show = get_frame_new_buffer(cm);
+  swap_frame_buffers(pbi);
 
   vp9_clear_system_state();
 
   cm->last_width = cm->width;
   cm->last_height = cm->height;
 
   if (!cm->show_existing_frame)
     cm->last_show_frame = cm->show_frame;
   if (cm->show_frame) {
     if (!cm->show_existing_frame)
@@ skipping 32 matching lines @@
     *sd = *cm->frame_to_show;
     ret = 0;
   }
 #else
   *sd = *cm->frame_to_show;
   ret = 0;
 #endif /*!CONFIG_POSTPROC*/
   vp9_clear_system_state();
   return ret;
 }