Add GetAssociatedOutputDeviceID support to pulse.

media/audio/pulse/pulse_util.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_AUDIO_PULSE_PULSE_UTIL_H_
 #define MEDIA_AUDIO_PULSE_PULSE_UTIL_H_
 
 #include <pulse/pulseaudio.h>
 
 #include "base/macros.h"
 #include "media/audio/audio_device_name.h"
 #include "media/base/channel_layout.h"
 
 namespace media {
 
 class AudioParameters;
 
 namespace pulse {
 
+enum class RequestType : int8_t { INPUT, OUTPUT };
+
 // A helper class that acquires pa_threaded_mainloop_lock() while in scope.
 class AutoPulseLock {
  public:
   explicit AutoPulseLock(pa_threaded_mainloop* pa_mainloop)
       : pa_mainloop_(pa_mainloop) {
     pa_threaded_mainloop_lock(pa_mainloop_);
   }
 
   ~AutoPulseLock() {
     pa_threaded_mainloop_unlock(pa_mainloop_);
@@ skipping 38 matching lines @@
 bool CreateOutputStream(pa_threaded_mainloop** mainloop,
                         pa_context** context,
                         pa_stream** stream,
                         const AudioParameters& params,
                         const std::string& device_id,
                         const std::string& app_name,
                         pa_stream_notify_cb_t stream_callback,
                         pa_stream_request_cb_t write_callback,
                         void* user_data);
 
+// Utility functions to match up outputs and inputs.
+std::string GetBusOfInput(pa_threaded_mainloop* mainloop,
+                          pa_context* context,
+                          const std::string& name);
+std::string GetOutputCorrespondingTo(pa_threaded_mainloop* mainloop,
+                                     pa_context* context,
+                                     const std::string& bus);
+std::string GetRealDefaultDeviceId(pa_threaded_mainloop* mainloop,
+                                   pa_context* context,
+                                   RequestType type);
 }  // namespace pulse
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_PULSE_PULSE_UTIL_H_