Chromecast: Add stream id interface in DecoderBufferBase class

chromecast/media/cma/base/decoder_buffer_base.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_
 #define CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_
 
 #include "base/basictypes.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 
 namespace media {
 class DecryptConfig;
 }
 
 namespace chromecast {
 namespace media {
 
+enum StreamId {
+  kPrimary = 0,
+  kSecondary
+};
+
 // DecoderBufferBase exposes only the properties of an audio/video buffer.
 // The way a DecoderBufferBase is created and organized in memory
 // is left as a detail of the implementation of derived classes.
 class DecoderBufferBase
     : public base::RefCountedThreadSafe<DecoderBufferBase> {
  public:
   DecoderBufferBase();
 
+  // Returns the stream id of this decoder buffer belonging to. it's optional
+  // and default value is kPrimary.
+  virtual StreamId stream_id() const = 0;
+
   // Returns the PTS of the frame.
   virtual base::TimeDelta timestamp() const = 0;
 
   // Gets the frame data.
   virtual const uint8* data() const = 0;
   virtual uint8* writable_data() const = 0;
 
   // Returns the size of the frame in bytes.
   virtual size_t data_size() const = 0;
 
@@ skipping 10 matching lines @@
   virtual ~DecoderBufferBase();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DecoderBufferBase);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_