Chromecast: Add stream id interface in DecoderBufferBase class

chromecast/media/cma/pipeline/decrypt_util.cc

Index: chromecast/media/cma/pipeline/decrypt_util.cc
diff --git a/chromecast/media/cma/pipeline/decrypt_util.cc b/chromecast/media/cma/pipeline/decrypt_util.cc
index 1f1fbe85c62bff47a347278455f7ba522712af2f..0010380ca3e048deb7f8cb6733764f86fe29ee7e 100644
--- a/chromecast/media/cma/pipeline/decrypt_util.cc
+++ b/chromecast/media/cma/pipeline/decrypt_util.cc
@@ -22,6 +22,7 @@ class DecoderBufferClear : public DecoderBufferBase {
   explicit DecoderBufferClear(const scoped_refptr<DecoderBufferBase>& buffer);
 
   // DecoderBufferBase implementation.
+  StreamId stream_id() const override;
   base::TimeDelta timestamp() const override;
   const uint8* data() const override;
   uint8* writable_data() const override;
@@ -45,6 +46,10 @@ DecoderBufferClear::DecoderBufferClear(
 DecoderBufferClear::~DecoderBufferClear() {
 }
 
+StreamId DecoderBufferClear::stream_id() const {
+  return buffer_->stream_id();
+}
+
 base::TimeDelta DecoderBufferClear::timestamp() const {
   return buffer_->timestamp();
 }