Revert 177842. This doesn't build in standalone webkit builds:

media/ffmpeg/ffmpeg_common.cc

Index: media/ffmpeg/ffmpeg_common.cc
===================================================================
--- media/ffmpeg/ffmpeg_common.cc	(revision 177952)
+++ media/ffmpeg/ffmpeg_common.cc	(working copy)
@@ -147,8 +147,6 @@
       return kCodecMPEG4;
     case CODEC_ID_VP8:
       return kCodecVP8;
-    case AV_CODEC_ID_VP9:
-      return kCodecVP9;
     default:
       DVLOG(1) << "Unknown video CodecID: " << codec_id;
   }
@@ -165,8 +163,6 @@
       return CODEC_ID_MPEG4;
     case kCodecVP8:
       return CODEC_ID_VP8;
-    case kCodecVP9:
-      return AV_CODEC_ID_VP9;
     default:
       DVLOG(1) << "Unknown VideoCodec: " << video_codec;
   }
@@ -339,28 +335,13 @@
     aspect_ratio = stream->codec->sample_aspect_ratio;
 
   VideoCodec codec = CodecIDToVideoCodec(stream->codec->codec_id);
-
-  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);
-
+  VideoCodecProfile profile = (codec == kCodecVP8) ? VP8PROFILE_MAIN :
+      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,
-                     format,
+                     PixelFormatToVideoFormat(stream->codec->pix_fmt),
                      coded_size, visible_rect, natural_size,
                      stream->codec->extradata, stream->codec->extradata_size,
                      false,  // Not encrypted.