Update padding/alignment constants to match ffmpeg.

media/ffmpeg/ffmpeg_common.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_FFMPEG_FFMPEG_COMMON_H_
 #define MEDIA_FFMPEG_FFMPEG_COMMON_H_
 
 // Used for FFmpeg error codes.
 #include <cerrno>
 
@@ skipping 13 matching lines @@
 // file or the headers below will generate different structures.
 #define FF_API_PIX_FMT_DESC 0
 #define FF_API_OLD_DECODE_AUDIO 0
 #define FF_API_DESTRUCT_PACKET 0
 #define FF_API_GET_BUFFER 0
 
 // Temporarily disable possible loss of data warning.
 // TODO(scherkus): fix and upstream the compiler warnings.
 MSVC_PUSH_DISABLE_WARNING(4244);
 #include <libavcodec/avcodec.h>
+#include <libavcodec/internal.h>

[wtc1, 2015/09/05 01:46:04]

The "internal.h" file name suggests this header is internal. Also it is not
installed in /usr/include/libavcodec on my Ubuntu 14.04 computer.

 #include <libavformat/avformat.h>
 #include <libavformat/internal.h>
 #include <libavformat/avio.h>
 #include <libavutil/avutil.h>
 #include <libavutil/imgutils.h>
 #include <libavutil/log.h>
 #include <libavutil/mathematics.h>
 #include <libavutil/opt.h>
 MSVC_POP_WARNING();
 }  // extern "C"
@@ skipping 84 matching lines @@
                                     AVColorRange color_range);
 
 // Convert FFmpeg UTC representation (YYYY-MM-DD HH:MM:SS) to base::Time.
 // Returns true and sets |*out| if |date_utc| contains a valid
 // date string. Otherwise returns fals and timeline_offset is unmodified.
 MEDIA_EXPORT bool FFmpegUTCDateToTime(const char* date_utc, base::Time* out);
 
 }  // namespace media
 
 #endif  // MEDIA_FFMPEG_FFMPEG_COMMON_H_