Encrypted Media: Support config change in DecryptingDemuxerStream.

media/filters/decrypting_demuxer_stream.h

Index: media/filters/decrypting_demuxer_stream.h
diff --git a/media/filters/decrypting_demuxer_stream.h b/media/filters/decrypting_demuxer_stream.h
index 73ba1fb5aad34fd4182c8edf5ff5fb9e604e9306..b51ce3e8b7a08a9f6b091c0a0ca8973a8824dd1a 100644
--- a/media/filters/decrypting_demuxer_stream.h
+++ b/media/filters/decrypting_demuxer_stream.h
@@ -91,6 +91,9 @@ class MEDIA_EXPORT DecryptingDemuxerStream : public DemuxerStream {
   // Returns Decryptor::StreamType converted from |stream_type_|.
   Decryptor::StreamType GetDecryptorStreamType() const;
 
+  // Sets |{audio|video}_config_| from |stream|.
+  void SetDecoderConfig(const scoped_refptr<DemuxerStream>& stream);
+
   scoped_refptr<base::MessageLoopProxy> message_loop_;
 
   State state_;