Wire up the output device id and provide an implementation on Windows.

media/audio/audio_output_dispatcher.h

 // Copyright (c) 2012 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.
 
 // AudioOutputDispatcher is a single-threaded base class that dispatches
 // creation and deletion of audio output streams. AudioOutputProxy objects use
 // this class to allocate and recycle actual audio output streams. When playback
 // is started, the proxy calls StartStream() to get an output stream that it
 // uses to play audio. When playback is stopped, the proxy returns the stream
 // back to the dispatcher by calling StopStream().
@@ skipping 20 matching lines @@
 
 namespace media {
 
 class AudioOutputProxy;
 
 class MEDIA_EXPORT AudioOutputDispatcher
     : public base::RefCountedThreadSafe<AudioOutputDispatcher> {
  public:
   AudioOutputDispatcher(AudioManager* audio_manager,
                         const AudioParameters& params,
+                        const std::string& output_device_id,
                         const std::string& input_device_id);
 
   // Called by AudioOutputProxy to open the stream.
   // Returns false, if it fails to open it.
   virtual bool OpenStream() = 0;
 
   // Called by AudioOutputProxy when the stream is started.
   // Uses |callback| to get source data and report errors, if any.
   // Does *not* take ownership of this callback.
   // Returns true if started successfully, false otherwise.
@@ skipping 21 matching lines @@
   friend class base::RefCountedThreadSafe<AudioOutputDispatcher>;
   friend class AudioOutputProxyTest;
 
   virtual ~AudioOutputDispatcher();
 
   // A no-reference-held pointer (we don't want circular references) back to the
   // AudioManager that owns this object.
   AudioManager* audio_manager_;
   base::MessageLoop* message_loop_;
   AudioParameters params_;
+  const std::string output_device_id_;
   const std::string input_device_id_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcher);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_H_