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

media/audio/pulse/audio_manager_pulse.cc

 // 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.
 
 #include "media/audio/pulse/audio_manager_pulse.h"
 
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
@@ skipping 158 matching lines @@
 
 AudioParameters AudioManagerPulse::GetPreferredOutputStreamParameters(
     const std::string& output_device_id,
     const AudioParameters& input_params) {
   // TODO(tommi): Support |output_device_id|.
   VLOG_IF(0, !output_device_id.empty()) << "Not implemented!";
 
   ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
   int buffer_size = kMinimumOutputBufferSize;
   int bits_per_sample = 16;
-  int input_channels = 0;
   int sample_rate = GetNativeSampleRate();
   if (input_params.IsValid()) {
     bits_per_sample = input_params.bits_per_sample();
     channel_layout = input_params.channel_layout();
-    input_channels = input_params.input_channels();
     buffer_size =
         std::min(kMaximumOutputBufferSize,
                  std::max(buffer_size, input_params.frames_per_buffer()));
   }
 
   int user_buffer_size = GetUserBufferSize();
   if (user_buffer_size)
     buffer_size = user_buffer_size;
 
   return AudioParameters(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, input_channels,
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
       sample_rate, bits_per_sample, buffer_size, AudioParameters::NO_EFFECTS);
 }
 
 AudioOutputStream* AudioManagerPulse::MakeOutputStream(
     const AudioParameters& params,
     const std::string& device_id) {
   DCHECK(!device_id.empty());
   return new PulseAudioOutputStream(params, device_id, this);
 }
 
@@ skipping 129 matching lines @@
 void AudioManagerPulse::SampleRateInfoCallback(pa_context* context,
                                                const pa_server_info* info,
                                                void* user_data) {
   AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);
 
   manager->native_input_sample_rate_ = info->sample_spec.rate;
   pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
 }
 
 }  // namespace media