Log AVERROR messages from FFmpegDemuxer in chrome://media-internals.

media/filters/ffmpeg_video_decoder.cc

Index: media/filters/ffmpeg_video_decoder.cc
diff --git a/media/filters/ffmpeg_video_decoder.cc b/media/filters/ffmpeg_video_decoder.cc
index ad30943d1d0284fc6d0c4946bd20643b7673d226..c6541e65fe8d2585ef0c794ab6a17f1d2f901f3f 100644
--- a/media/filters/ffmpeg_video_decoder.cc
+++ b/media/filters/ffmpeg_video_decoder.cc
@@ -362,7 +362,8 @@ bool FFmpegVideoDecoder::FFmpegDecode(
   // Log the problem if we can't decode a video frame and exit early.
   if (result < 0) {
     MEDIA_LOG(DEBUG, media_log_)
-        << "avcodec_decode_video2(): " << AVErrorToString(result) << ", at "
+        << GetDisplayName()
+        << ": avcodec_decode_video2(): " << AVErrorToString(result) << ", at "
         << buffer->AsHumanReadableString();
     return false;
   }