Allow AudioOutputDevice objects to be initialized with a specific hardware output device and store …

content/renderer/media/audio_device_factory.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.
 
 #ifndef CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_FACTORY_H_
 #define CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_FACTORY_H_
 
+#include <string>
+
 #include "base/basictypes.h"
+#include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 
+class GURL;
+
 namespace media {
 class AudioInputDevice;
 class AudioOutputDevice;
 }
 
 namespace content {
 
 // A factory for creating AudioOutputDevices and AudioInputDevices.  There is a
 // global factory function that can be installed for the purposes of testing to
 // provide specialized implementations.
 class CONTENT_EXPORT AudioDeviceFactory {
  public:
-  // Creates an AudioOutputDevice using the currently registered factory.
+  // Creates an AudioOutputDevice.
   // |render_frame_id| refers to the RenderFrame containing the entity
-  // producing the audio.
+  // producing the audio. If |session_id| is nonzero, it is used by the browser
+  // to select the correct input device ID and its associated output device, if
+  // it exists. If |session_id| is zero, |device_id| and |security_origin|
+  // identify the output device to use.
+  // If |session_id| is zero and |device_id| and |security_origin| are empty,
+  // the default output device will be selected.
   static scoped_refptr<media::AudioOutputDevice> NewOutputDevice(
-      int render_frame_id);
+      int render_frame_id,
+      int session_id,
+      const std::string& device_id,
+      const GURL& security_origin);
 
   // Creates an AudioInputDevice using the currently registered factory.
   // |render_frame_id| refers to the RenderFrame containing the entity
   // consuming the audio.
   static scoped_refptr<media::AudioInputDevice> NewInputDevice(
       int render_frame_id);
 
  protected:
   AudioDeviceFactory();
   virtual ~AudioDeviceFactory();
 
   // You can derive from this class and specify an implementation for these
   // functions to provide alternate audio device implementations.
   // If the return value of either of these function is NULL, we fall back
   // on the default implementation.
-  virtual media::AudioOutputDevice* CreateOutputDevice(int render_frame_id) = 0;
+  virtual media::AudioOutputDevice* CreateOutputDevice(
+      int render_frame_id,
+      int sesssion_id,
+      const std::string& device_id,
+      const GURL& security_origin) = 0;
   virtual media::AudioInputDevice* CreateInputDevice(int render_frame_id) = 0;
 
  private:
   // The current globally registered factory. This is NULL when we should
   // create the default AudioRendererSinks.
   static AudioDeviceFactory* factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDeviceFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_FACTORY_H_