Revert of Revert of Remove the last piece of deprecated synchronous IO code.

components/copresence/mediums/audio/audio_recorder.cc

 // Copyright 2014 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.
 
 #include "components/copresence/mediums/audio/audio_recorder.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 86 matching lines @@
   DCHECK(media::AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
 
   media::AudioParameters params =
       params_for_testing_
           ? *params_for_testing_
           : media::AudioManager::Get()->GetInputStreamParameters(
                 media::AudioManagerBase::kDefaultDeviceId);
 
   const media::AudioParameters dest_params(params.format(),
                                            kDefaultChannelLayout,
-                                           kDefaultChannels,
-                                           params.input_channels(),
                                            kDefaultSampleRate,
                                            kDefaultBitsPerSample,
                                            params.frames_per_buffer(),
                                            media::AudioParameters::NO_EFFECTS);
 
   converter_.reset(new media::AudioConverter(
       params, dest_params, params.sample_rate() == dest_params.sample_rate()));
   converter_->AddInput(this);
 
   total_buffer_frames_ = kProcessIntervalMs * dest_params.sample_rate() / 1000;
@@ skipping 125 matching lines @@
   base::RunLoop rl;
   media::AudioManager::Get()->GetTaskRunner()->PostTaskAndReply(
       FROM_HERE,
       base::Bind(base::IgnoreResult(&AudioRecorder::FlushAudioLoopForTesting),
                  base::Unretained(this)),
       rl.QuitClosure());
   rl.Run();
 }
 
 }  // namespace copresence