libvpx: Pull from upstream

source/libvpx/vp9/decoder/vp9_decoder.h

 /*
  *  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 37 matching lines @@
 
   int ready_for_new_data;
 
   int refresh_frame_flags;
 
   int frame_parallel_decode;  // frame-based threading.
 
   // TODO(hkuang): Combine this with cur_buf in macroblockd as they are
   // the same.
   RefCntBuffer *cur_buf;   //  Current decoding frame buffer.
-  RefCntBuffer *prev_buf;  //  Previous decoding frame buffer.
 
   VP9Worker *frame_worker_owner;   // frame_worker that owns this pbi.
   VP9Worker lf_worker;
   VP9Worker *tile_workers;
   TileWorkerData *tile_worker_data;
   TileInfo *tile_worker_info;
   int num_tile_workers;
 
   TileData *tile_data;
   int total_tiles;
@@ skipping 59 matching lines @@
       pool->release_fb_cb(pool->cb_priv, &frame_bufs[idx].raw_frame_buffer);
     }
   }
 }
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // VP9_DECODER_VP9_DECODER_H_