Remove libvpx from FFmpeg in favour of ffvp8.

ffmpeg/source/config/Chromium/linux/x64/config.asm

Index: ffmpeg/source/config/Chromium/linux/x64/config.asm
diff --git a/ffmpeg/source/config/Chromium/linux/x64/config.asm b/ffmpeg/source/config/Chromium/linux/x64/config.asm
index e463dd5e3d9143abe9a40ecea815a6c38a3cafe6..4ac806f4c93cf35632267ec8ea768a6e0e8cb631 100644
--- a/ffmpeg/source/config/Chromium/linux/x64/config.asm
+++ b/ffmpeg/source/config/Chromium/linux/x64/config.asm
@@ -66,7 +66,7 @@
 %define HAVE_YASM
 %define CONFIG_DECODERS
 %define CONFIG_DEMUXERS
-%define CONFIG_ENCODERS
+%define CONFIG_PARSERS
 %define CONFIG_PROTOCOLS
 %define CONFIG_AVCODEC
 %define CONFIG_AVDEVICE
@@ -76,7 +76,7 @@
 %define CONFIG_FFPROBE
 %define CONFIG_FFT
 %define CONFIG_GOLOMB
-%define CONFIG_LIBVPX
+%define CONFIG_H264PRED
 %define CONFIG_MDCT
 %define CONFIG_PIC
 %define CONFIG_RDFT
@@ -86,12 +86,12 @@
 %define CONFIG_AVUTIL
 %define CONFIG_THEORA_DECODER
 %define CONFIG_VP3_DECODER
+%define CONFIG_VP8_DECODER
 %define CONFIG_VORBIS_DECODER
 %define CONFIG_PCM_F32LE_DECODER
 %define CONFIG_PCM_S16LE_DECODER
 %define CONFIG_PCM_U8_DECODER
-%define CONFIG_LIBVPX_DECODER
-%define CONFIG_LIBVPX_ENCODER
+%define CONFIG_VP8_PARSER
 %define CONFIG_MATROSKA_DEMUXER
 %define CONFIG_OGG_DEMUXER
 %define CONFIG_WAV_DEMUXER