Moving SwitchOutputDevice out of OutputDevice interface, eliminating OutputDevice

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/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "media/base/audio_renderer_sink.h"
 
 namespace media {
 class AudioInputDevice;
-class AudioOutputDevice;
 }
 
 namespace url {
 class Origin;
 }
 
 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:
   // Types of audio sources.
   enum SourceType {
     kSourceNone = 0,
     kSourceMediaElement,
     kSourceWebRtc,
     kSourceNonRtcAudioTrack,
     kSourceWebAudio,
     kSourceLast = kSourceWebAudio  // Only used for validation of format.
   };
 
-  // Creates an AudioOutputDevice.
+  // Creates a sink for AudioRendererMixer.
   // |render_frame_id| refers to the RenderFrame containing the entity
   // 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(
+  static scoped_refptr<media::AudioRendererSink> NewAudioRendererMixerSink(
       int render_frame_id,
       int session_id,
       const std::string& device_id,
       const url::Origin& security_origin);
 
   // Creates an AudioRendererSink bound to an AudioOutputDevice.
   // Basing on |source_type| and build configuration, audio played out through
   // the sink goes to AOD directly or can be mixed with other audio before that.
   // TODO(olka): merge it with NewRestartableOutputDevice() as soon as
   // AudioOutputDevice is fixed to be restartable.
   static scoped_refptr<media::AudioRendererSink> NewAudioRendererSink(
       SourceType source_type,
       int render_frame_id,
       int session_id,
       const std::string& device_id,
       const url::Origin& security_origin);
 
-  // Creates a RestartableAudioRendererSink bound to an AudioOutputDevice
+  // Creates a SwitchableAudioRendererSink bound to an AudioOutputDevice
   // Basing on |source_type| and build configuration, audio played out through
   // the sink goes to AOD directly or can be mixed with other audio before that.
-  static scoped_refptr<media::RestartableAudioRendererSink>
-  NewRestartableAudioRendererSink(SourceType source_type,
-                                  int render_frame_id,
-                                  int session_id,
-                                  const std::string& device_id,
-                                  const url::Origin& security_origin);
+  static scoped_refptr<media::SwitchableAudioRendererSink>
+  NewSwitchableAudioRendererSink(SourceType source_type,
+                                 int render_frame_id,
+                                 int session_id,
+                                 const std::string& device_id,
+                                 const url::Origin& security_origin);
 
   // A helper to get HW device status in the absence of AudioOutputDevice.
   static media::OutputDeviceStatus GetOutputDeviceStatus(

[Guido Urdaneta, 2016/03/22 15:30:18]

What if we change this to return the whole OutputDeviceInfo?
I think it can be more useful while having the same cost.

[o1ka, 2016/03/22 16:13:55]

Done.

       int render_frame_id,
       int session_id,
       const std::string& device_id,
       const url::Origin& 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(
+  virtual scoped_refptr<media::AudioRendererSink> CreateAudioRendererMixerSink(
       int render_frame_id,
       int sesssion_id,
       const std::string& device_id,
       const url::Origin& security_origin) = 0;
 
-  virtual media::AudioRendererSink* CreateAudioRendererSink(
+  virtual scoped_refptr<media::AudioRendererSink> CreateAudioRendererSink(
       SourceType source_type,
       int render_frame_id,
       int sesssion_id,
       const std::string& device_id,
       const url::Origin& security_origin) = 0;
 
-  virtual media::RestartableAudioRendererSink*
-  CreateRestartableAudioRendererSink(SourceType source_type,
-                                     int render_frame_id,
-                                     int sesssion_id,
-                                     const std::string& device_id,
-                                     const url::Origin& security_origin) = 0;
+  virtual scoped_refptr<media::SwitchableAudioRendererSink>
+  CreateSwitchableAudioRendererSink(SourceType source_type,
+                                    int render_frame_id,
+                                    int sesssion_id,
+                                    const std::string& device_id,
+                                    const url::Origin& security_origin) = 0;
 
-  virtual media::AudioInputDevice* CreateInputDevice(int render_frame_id) = 0;
+  virtual scoped_refptr<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_