[Chromecast] Implement new volume control API

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

 // 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.
 
 #include "chromecast/media/cma/backend/alsa/stream_mixer_alsa_input.h"
 
 #include <utility>
 
 #include "chromecast/media/cma/backend/alsa/stream_mixer_alsa.h"
 #include "chromecast/media/cma/backend/alsa/stream_mixer_alsa_input_impl.h"
 
 namespace chromecast {
 namespace media {
 
 StreamMixerAlsaInput::StreamMixerAlsaInput(Delegate* delegate,
                                            int samples_per_second,
                                            bool primary,
-                                           const std::string& device_id) {
-  std::unique_ptr<StreamMixerAlsaInputImpl> impl(
-      new StreamMixerAlsaInputImpl(delegate, samples_per_second, primary,
-                                   device_id, StreamMixerAlsa::Get()));
+                                           const std::string& device_id,
+                                           AudioContentType content_type) {
+  std::unique_ptr<StreamMixerAlsaInputImpl> impl(new StreamMixerAlsaInputImpl(
+      delegate, samples_per_second, primary, device_id, content_type,
+      StreamMixerAlsa::Get()));
   impl_ = impl.get();  // Store a pointer to the impl, but the mixer owns it.
   StreamMixerAlsa::Get()->AddInput(std::move(impl));
 }
 
 StreamMixerAlsaInput::~StreamMixerAlsaInput() {
   DCHECK(thread_checker_.CalledOnValidThread());
   impl_->PreventDelegateCalls();
   StreamMixerAlsa::Get()->RemoveInput(impl_);
 }
 
 void StreamMixerAlsaInput::WritePcm(
     const scoped_refptr<DecoderBufferBase>& data) {
   DCHECK(thread_checker_.CalledOnValidThread());
   impl_->WritePcm(data);
 }
 
 void StreamMixerAlsaInput::SetPaused(bool paused) {
   DCHECK(thread_checker_.CalledOnValidThread());
   impl_->SetPaused(paused);
 }
 
 void StreamMixerAlsaInput::SetVolumeMultiplier(float multiplier) {
   DCHECK(thread_checker_.CalledOnValidThread());
   impl_->SetVolumeMultiplier(multiplier);
 }
 
 }  // namespace media
 }  // namespace chromecast