Moving SwitchOutputDevice out of OutputDevice interface, eliminating OutputDevice

content/public/renderer/media_stream_audio_renderer.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.
 
 #ifndef CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_AUDIO_RENDERER_H_
 #define CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_AUDIO_RENDERER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 23 matching lines @@
   // Sets the output volume.
   virtual void SetVolume(float volume) = 0;
 
   // Returns a pointer to the internal output device.
   // The pointer is not to be owned by the caller and is valid only during
   // the lifetime of the MediaStreamAudioRenderer.
   // It can be null, which means that access to the output device is not
   // supported.
   virtual media::OutputDevice* GetOutputDevice() = 0;
 
+  // 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
+  // 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 media::OutputDeviceStatusCB& callback) = 0;
+
   // Time stamp that reflects the current render time. Should not be updated
   // when paused.
   virtual base::TimeDelta GetCurrentRenderTime() const = 0;
 
   // Returns true if the implementation is a local renderer and false
   // otherwise.
   virtual bool IsLocalRenderer() const = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<MediaStreamAudioRenderer>;
 
   virtual ~MediaStreamAudioRenderer() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_AUDIO_RENDERER_H_