Add libvpx wrapper to media to support VP9 video decoding.

media/ffmpeg/ffmpeg_common.cc

Index: media/ffmpeg/ffmpeg_common.cc
diff --git a/media/ffmpeg/ffmpeg_common.cc b/media/ffmpeg/ffmpeg_common.cc
index 1fd5cd9991f82edbb8447f69c4e432c8102f2aca..3562ec3fdea4823211714ecd6ad780f0a01957d4 100644
--- a/media/ffmpeg/ffmpeg_common.cc
+++ b/media/ffmpeg/ffmpeg_common.cc
@@ -10,6 +10,10 @@
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
 
+// TODO(tomfinegan): Remove this once FFmpeg rolls for M25. The VP9 patch is in
+// tree, but this is required until the roll happens.
+#define AV_CODEC_ID_VP9 170
+
 namespace media {
 
 // Why FF_INPUT_BUFFER_PADDING_SIZE? FFmpeg assumes all input buffers are
@@ -149,6 +153,11 @@ VideoCodec CodecIDToVideoCodec(CodecID codec_id) {
     case CODEC_ID_VP8:
       return kCodecVP8;
     default:
+      if (codec_id == AV_CODEC_ID_VP9) {
+        // TODO(tomfinegan): Remove this once FFmpeg rolls for M25, and
+        // AV_CODEC_ID_VP9 is part of CodecID.
+        return kCodecVP9;
+      }
       DVLOG(1) << "Unknown video CodecID: " << codec_id;
   }
   return kUnknownVideoCodec;
@@ -168,6 +177,10 @@ static CodecID VideoCodecToCodecID(VideoCodec video_codec) {
       return CODEC_ID_MPEG4;
     case kCodecVP8:
       return CODEC_ID_VP8;
+    case kCodecVP9:
+      // TODO(tomfinegan): Remove this cast once FFmpeg rolls for M25, and the
+      // local define for AV_CODEC_ID_VP9 is removed.
+      return static_cast<CodecID>(AV_CODEC_ID_VP9);
     default:
       DVLOG(1) << "Unknown VideoCodec: " << video_codec;
   }
@@ -311,13 +324,28 @@ void AVStreamToVideoDecoderConfig(
     aspect_ratio = stream->codec->sample_aspect_ratio;
 
   VideoCodec codec = CodecIDToVideoCodec(stream->codec->codec_id);
-  VideoCodecProfile profile = (codec == kCodecVP8) ? VP8PROFILE_MAIN :
-      ProfileIDToVideoCodecProfile(stream->codec->profile);
+
+  VideoCodecProfile profile = VIDEO_CODEC_PROFILE_UNKNOWN;
+  if (codec == kCodecVP8)
+    profile = VP8PROFILE_MAIN;
+  else if (codec == kCodecVP9)
+    profile = VP9PROFILE_MAIN;
+  else
+    profile = ProfileIDToVideoCodecProfile(stream->codec->profile);
+
   gfx::Size natural_size = GetNaturalSize(
       visible_rect.size(), aspect_ratio.num, aspect_ratio.den);
+
+  VideoFrame::Format format = PixelFormatToVideoFormat(stream->codec->pix_fmt);
+  if (codec == kCodecVP9) {
+    // TODO(tomfinegan): libavcodec doesn't know about VP9.
+    format = VideoFrame::YV12;
+    coded_size = natural_size;
+  }
+
   config->Initialize(codec,
                      profile,
-                     PixelFormatToVideoFormat(stream->codec->pix_fmt),
+                     format,
                      coded_size, visible_rect, natural_size,
                      stream->codec->extradata, stream->codec->extradata_size,
                      false,  // Not encrypted.