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

media/audio/cras/audio_manager_cras.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/cras/audio_manager_cras.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/environment.h"
@@ skipping 106 matching lines @@
 
 AudioParameters AudioManagerCras::GetPreferredOutputStreamParameters(
     const std::string& output_device_id,
     const AudioParameters& input_params) {
   // TODO(tommi): Support |output_device_id|.
   DLOG_IF(ERROR, !output_device_id.empty()) << "Not implemented!";
   ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
   int sample_rate = kDefaultSampleRate;
   int buffer_size = kMinimumOutputBufferSize;
   int bits_per_sample = 16;
-  int input_channels = 0;
   if (input_params.IsValid()) {
     sample_rate = input_params.sample_rate();
     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* AudioManagerCras::MakeOutputStream(
     const AudioParameters& params) {
   return new CrasUnifiedStream(params, this);
 }
 
 AudioInputStream* AudioManagerCras::MakeInputStream(
     const AudioParameters& params, const std::string& device_id) {
   return new CrasInputStream(params, this, device_id);
 }
 
 snd_pcm_format_t AudioManagerCras::BitsToFormat(int bits_per_sample) {
   switch (bits_per_sample) {
     case 8:
       return SND_PCM_FORMAT_U8;
     case 16:
       return SND_PCM_FORMAT_S16;
     case 24:
       return SND_PCM_FORMAT_S24;
     case 32:
       return SND_PCM_FORMAT_S32;
     default:
       return SND_PCM_FORMAT_UNKNOWN;
   }
 }
 
 }  // namespace media