libvpx: Pull from upstream

source/libvpx/y4menc.h

 /*
  *  Copyright (c) 2014 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 Y4MENC_H_
 #define Y4MENC_H_
 
 #include "./tools_common.h"
 
 #include "vpx/vpx_decoder.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 #define Y4M_BUFFER_SIZE 128
 
 int y4m_write_file_header(char *buf, size_t len, int width, int height,
                           const struct VpxRational *framerate,
-                          vpx_img_fmt_t fmt);
+                          vpx_img_fmt_t fmt, unsigned int bit_depth);
 int y4m_write_frame_header(char *buf, size_t len);
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // Y4MENC_H_