fix parsing error at the end of stream

media/filters/ffmpeg_demuxer.cc

Index: media/filters/ffmpeg_demuxer.cc
diff --git a/media/filters/ffmpeg_demuxer.cc b/media/filters/ffmpeg_demuxer.cc
index 4092023906d4671527af8a83cb1617c44ada8ab3..c47250467f09df11d6978daf0a369f8a9206a953 100644
--- a/media/filters/ffmpeg_demuxer.cc
+++ b/media/filters/ffmpeg_demuxer.cc
@@ -117,7 +117,7 @@ base::TimeDelta FFmpegDemuxerStream::EnqueuePacket(AVPacket* packet) {
   }
 
   // Convert if the packet if there is bitstream filter.
-  if (bitstream_converter_.get() &&
+  if (packet->data && bitstream_converter_.get() &&
       !bitstream_converter_->ConvertPacket(packet)) {
     LOG(ERROR) << "Format converstion failed.";
   }