DecoderStreamTraits: remove redundant explicit instantiation definitions

media/filters/decoder_stream_traits.cc

Index: media/filters/decoder_stream_traits.cc
diff --git a/media/filters/decoder_stream_traits.cc b/media/filters/decoder_stream_traits.cc
index e59d99f9d66392a12afa4ac54443828ad3dd2be3..deaedddc372ab73126eaf0f7ba183c2a716358e3 100644
--- a/media/filters/decoder_stream_traits.cc
+++ b/media/filters/decoder_stream_traits.cc
@@ -103,7 +103,4 @@ void DecoderStreamTraits<DemuxerStream::AUDIO>::OnDecodeDone(
   audio_ts_validator_->RecordOutputDuration(buffer);
 }
 
-template class DecoderStreamTraits<DemuxerStream::VIDEO>;
-template class DecoderStreamTraits<DemuxerStream::AUDIO>;
-
 }  // namespace media