Enable pinning stream output routing for webapp request on ChromeOS

media/audio/cras/cras_unified.h

 // Copyright 2013 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.
 //
 // Creates a unified stream based on the cras (ChromeOS audio server) interface.
 //
 // CrasUnifiedStream object is *not* thread-safe and should only be used
 // from the audio thread.
 
 #ifndef MEDIA_AUDIO_CRAS_CRAS_UNIFIED_H_
@@ skipping 17 matching lines @@
 
 // Implementation of AudioOuputStream for Chrome OS using the Chrome OS audio
 // server.
 // TODO(dgreid): This class is used for only output, either remove all the
 // relevant input code and change the class to CrasOutputStream or merge
 // cras_input.cc into this unified implementation.
 class MEDIA_EXPORT CrasUnifiedStream : public AudioOutputStream {
  public:
   // The ctor takes all the usual parameters, plus |manager| which is the
   // audio manager who is creating this object.
-  CrasUnifiedStream(const AudioParameters& params, AudioManagerCras* manager);
+  CrasUnifiedStream(const AudioParameters& params,
+                    AudioManagerCras* manager,
+                    const std::string& device_id);
 
   // The dtor is typically called by the AudioManager only and it is usually
   // triggered by calling AudioUnifiedStream::Close().
   ~CrasUnifiedStream() override;
 
   // Implementation of AudioOutputStream.
   bool Open() override;
   void Close() override;
   void Start(AudioSourceCallback* callback) override;
   void Stop() override;
@@ skipping 55 matching lines @@
 
   // Callback to get audio samples.
   AudioSourceCallback* source_callback_;
 
   // Container for exchanging data with AudioSourceCallback::OnMoreData().
   std::unique_ptr<AudioBus> output_bus_;
 
   // Direciton of the stream.
   CRAS_STREAM_DIRECTION stream_direction_;
 
+  // Index of the CRAS device to stream output to.
+  int pin_device_;
+
   DISALLOW_COPY_AND_ASSIGN(CrasUnifiedStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_CRAS_CRAS_UNIFIED_H_