libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_writer.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.
  */
 
 #ifndef VP9_ENCODER_VP9_WRITER_H_
 #define VP9_ENCODER_VP9_WRITER_H_
 
 #include "vpx_ports/mem.h"
 
 #include "vp9/common/vp9_prob.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef struct {
+typedef struct vp9_writer {
   unsigned int lowvalue;
   unsigned int range;
   int count;
   unsigned int pos;
   uint8_t *buffer;
 } vp9_writer;
 
 void vp9_start_encode(vp9_writer *bc, uint8_t *buffer);
 void vp9_stop_encode(vp9_writer *bc);
 
@@ skipping 56 matching lines @@
     vp9_write_bit(w, 1 & (data >> bit));
 }
 
 #define vp9_write_prob(w, v) vp9_write_literal((w), (v), 8)
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // VP9_ENCODER_VP9_WRITER_H_