Refactor AudioParameters member setting.

media/audio/mac/audio_manager_mac.cc

 // 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.
 
 #include "media/audio/mac/audio_manager_mac.h"
 
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/mac/mac_logging.h"
@@ skipping 654 matching lines @@
   // work correctly.
   int output_channels = input_params.channels();
   ChannelLayout channel_layout = input_params.channel_layout();
   if (!has_valid_input_params || output_channels > hardware_channels) {
     output_channels = hardware_channels;
     channel_layout = GuessChannelLayout(output_channels);
     if (channel_layout == CHANNEL_LAYOUT_UNSUPPORTED)
       channel_layout = CHANNEL_LAYOUT_DISCRETE;
   }
 
-  return AudioParameters(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, output_channels,
-      hardware_sample_rate, 16, buffer_size, AudioParameters::NO_EFFECTS);
+  AudioParameters params(AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
+                         hardware_sample_rate, 16, buffer_size,
+                         AudioParameters::NO_EFFECTS);
+  params.set_channels_for_discrete(output_channels);
+  return params;
 }
 
 void AudioManagerMac::InitializeOnAudioThread() {
   DCHECK(GetTaskRunner()->BelongsToCurrentThread());
   power_observer_.reset(new AudioPowerObserver());
 }
 
 void AudioManagerMac::ShutdownOnAudioThread() {
   DCHECK(GetTaskRunner()->BelongsToCurrentThread());
   output_device_listener_.reset();
@@ skipping 137 matching lines @@
     basic_input_streams_.erase(stream_it);
 
   AudioManagerBase::ReleaseInputStream(stream);
 }
 
 AudioManager* CreateAudioManager(AudioLogFactory* audio_log_factory) {
   return new AudioManagerMac(audio_log_factory);
 }
 
 }  // namespace media