Moving SwitchOutputDevice out of OutputDevice interface, eliminating OutputDevice

media/base/output_device.h

-// Copyright (c) 2015 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_OUTPUT_DEVICE_H_
-#define MEDIA_BASE_OUTPUT_DEVICE_H_
-
-#include <string>
-
-#include "base/callback.h"
-#include "media/audio/audio_parameters.h"
-#include "media/base/media_export.h"
-#include "url/origin.h"
-
-namespace media {
-
-// Result of an audio output device switch operation
-enum OutputDeviceStatus {
-  OUTPUT_DEVICE_STATUS_OK = 0,
-  OUTPUT_DEVICE_STATUS_ERROR_NOT_FOUND,
-  OUTPUT_DEVICE_STATUS_ERROR_NOT_AUTHORIZED,
-  OUTPUT_DEVICE_STATUS_ERROR_INTERNAL,
-  OUTPUT_DEVICE_STATUS_LAST = OUTPUT_DEVICE_STATUS_ERROR_INTERNAL,
-};
-
-typedef base::Callback<void(OutputDeviceStatus)> SwitchOutputDeviceCB;
-
-// OutputDevice is an interface that allows performing operations related
-// audio output devices.
-
-class OutputDevice {
- 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::SwitchOutputDeviceResult 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 SwitchOutputDeviceCB& callback) = 0;
-
-  // Returns the device's audio output parameters.
-  // The return value is undefined if the device status (as returned by
-  // GetDeviceStatus()) is different from OUTPUT_DEVICE_STATUS_OK.
-  // If the parameters are not available, this method may block until they
-  // become available.
-  // This method must never be called on the IO thread.
-  virtual AudioParameters GetOutputParameters() = 0;
-
-  // Returns the status of output device.
-  // If the status is not available, this method may block until it becomes
-  // available. Must never be called on the IO thread.
-  virtual OutputDeviceStatus GetDeviceStatus() = 0;
-
- protected:
-  virtual ~OutputDevice() {}
-};
-
-}  // namespace media
-
-#endif  // MEDIA_BASE_OUTPUT_DEVICE_H_