Add SupportsConfigChanges() to DemuxerStream.

media/filters/decrypting_demuxer_stream.cc

Index: media/filters/decrypting_demuxer_stream.cc
diff --git a/media/filters/decrypting_demuxer_stream.cc b/media/filters/decrypting_demuxer_stream.cc
index b069567a0645966539c59511a34a28401c32294c..821ea8b6541dbfd780c6b0afc636640f0879c81a 100644
--- a/media/filters/decrypting_demuxer_stream.cc
+++ b/media/filters/decrypting_demuxer_stream.cc
@@ -161,6 +161,10 @@ void DecryptingDemuxerStream::EnableBitstreamConverter() {
   demuxer_stream_->EnableBitstreamConverter();
 }
 
+bool DecryptingDemuxerStream::SupportsConfigChanges() {
+  return demuxer_stream_->SupportsConfigChanges();
+}
+
 DecryptingDemuxerStream::~DecryptingDemuxerStream() {
   DVLOG(2) << __FUNCTION__ << " : state_ = " << state_;
 }