[Chromecast] Implement new volume control API

chromecast/media/cma/backend/alsa/stream_mixer_alsa_input.h

 // Copyright 2015 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_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_H_
 #define CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread_checker.h"
 #include "chromecast/media/cma/backend/alsa/media_pipeline_backend_alsa.h"
 #include "chromecast/public/media/media_pipeline_device_params.h"
+#include "chromecast/public/volume_control.h"
 
 namespace chromecast {
 namespace media {
 
 class DecoderBufferBase;
 class StreamMixerAlsaInputImpl;
 
 // Input handle to the mixer. All methods (including constructor and destructor)
 // must be called on the same thread.
 class StreamMixerAlsaInput {
@@ skipping 20 matching lines @@
 
    protected:
     virtual ~Delegate() {}
   };
 
   // Adds a new input to the mixer, creating the mixer if it does not already
   // exist.
   StreamMixerAlsaInput(Delegate* delegate,
                        int samples_per_second,
                        bool primary,
-                       const std::string& device_id);
+                       const std::string& device_id,
+                       AudioContentType content_type);
   // Removes this input from the mixer, destroying the mixer if there are no
   // remaining inputs.
   ~StreamMixerAlsaInput();
 
   // Writes some PCM data to be mixed. |data| must be in planar float format.
   // Once the data has been written, the delegate's OnWritePcmCompletion()
   // method will be called on the same thread that the StreamMixerAlsaInput was
   // created on. Note that no further calls to WritePcm() should be made until
   // OnWritePcmCompletion() has been called.
   void WritePcm(const scoped_refptr<DecoderBufferBase>& data);
@@ skipping 10 matching lines @@
   StreamMixerAlsaInputImpl* impl_;
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(StreamMixerAlsaInput);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_H_