Moving SwitchOutputDevice out of OutputDevice interface, eliminating OutputDevice

media/base/audio_renderer_sink.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 MEDIA_BASE_AUDIO_RENDERER_SINK_H_
 #define MEDIA_BASE_AUDIO_RENDERER_SINK_H_
 
 #include <stdint.h>
 
 #include <string>
-#include <vector>
 
 #include "base/callback.h"
-#include "base/logging.h"
 #include "base/memory/ref_counted.h"
-#include "media/audio/audio_output_ipc.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_bus.h"
-#include "media/base/media_export.h"
-#include "media/base/output_device.h"
-#include "url/gurl.h"
-
-namespace base {
-class SingleThreadTaskRunner;
-}
+#include "media/base/output_device_info.h"
+#include "url/origin.h"
 
 namespace media {
 
 // AudioRendererSink is an interface representing the end-point for
 // rendered audio.  An implementation is expected to
 // periodically call Render() on a callback object.
 
 class AudioRendererSink
     : public base::RefCountedThreadSafe<media::AudioRendererSink> {
  public:
@@ skipping 28 matching lines @@
   // Pauses playback.
   virtual void Pause() = 0;
 
   // Resumes playback after calling Pause().
   virtual void Play() = 0;
 
   // Sets the playback volume, with range [0.0, 1.0] inclusive.
   // Returns |true| on success.
   virtual bool SetVolume(double volume) = 0;
 
-  // Returns a pointer to the internal output device.
-  // This pointer is not to be owned by the caller and is valid only during
-  // the lifetime of the AudioRendererSink.
-  // It can be null, which means that access to the output device is not
-  // supported.
-  virtual OutputDevice* GetOutputDevice() = 0;
+  // Returns current output device information. If the information is not
+  // available yet, this method may block until it becomes available.
+  // If the sink does not support output device, |device_status| of

[miu, 2016/03/24 21:32:02]

nit: s/does not support output device/is not an output device implementation/

[o1ka, 2016/03/29 13:39:54]

(The sink needs to be associated with OD, but not necessarily implements it:
since we don't have OD interface, "implement" is not quite applicable any more.
Also, a sink can be build on top of another sink and thus it's associated with
OD through that lower sink.)

Fixed.

+  // OutputDeviceInfo should be set to OUTPUT_DEVICE_STATUS_ERROR_INTERNAL.
+  // Must never be called on the IO thread.
+  virtual OutputDeviceInfo GetOutputDeviceInfo() = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<AudioRendererSink>;
   virtual ~AudioRendererSink() {}
 };
 
 // Same as AudioRendererSink except that Initialize() and Start() can be called
 // again after Stop().
 // TODO(sandersd): Fold back into AudioRendererSink once all subclasses support
 // this.
 
 class RestartableAudioRendererSink : public AudioRendererSink {
  protected:
   ~RestartableAudioRendererSink() override {}
 };
 
+class SwitchableAudioRendererSink : public RestartableAudioRendererSink {
+ public:
+  // Attempts to switch the audio output device.
+  // Once the attempt is finished, |callback| is invoked with the
+  // result of the operation passed as a parameter. The result is a value from
+  // the media::OutputDeviceStatus enum.
+  // There is no guarantee about the thread where |callback| will

[miu, 2016/03/24 21:32:02]

ditto here (see comments in
content/public/renderer/media_stream_audio_renderer.h).

[o1ka, 2016/03/29 13:39:54]

Done.

+  // be invoked, so users are advised to use media::BindToCurrentLoop() to
+  // ensure that |callback| runs on the correct thread.
+  // Note also that copy constructors and destructors for arguments bound to
+  // |callback| may run on arbitrary threads as |callback| is moved across
+  // threads. It is advisable to bind arguments such that they are released by
+  // |callback| when it runs in order to avoid surprises.
+  virtual void SwitchOutputDevice(const std::string& device_id,
+                                  const url::Origin& security_origin,
+                                  const OutputDeviceStatusCB& callback) = 0;
+
+ protected:
+  ~SwitchableAudioRendererSink() override {}
+};
+
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_RENDERER_SINK_H_