Refactor AudioParameters member setting.

media/base/audio_buffer_converter.cc

Index: media/base/audio_buffer_converter.cc
diff --git a/media/base/audio_buffer_converter.cc b/media/base/audio_buffer_converter.cc
index 0297ff6a3d29d585757731372da52067f4bbbb78..a927de2eb50a0794789d11110e838b236886dea5 100644
--- a/media/base/audio_buffer_converter.cc
+++ b/media/base/audio_buffer_converter.cc
@@ -141,7 +141,6 @@ void AudioBufferConverter::ResetConverter(
   input_params_.Reset(
       input_params_.format(),
       buffer->channel_layout(),
-      buffer->channel_count(),
       buffer->sample_rate(),
       input_params_.bits_per_sample(),
       // If resampling is needed and the FIFO disabled, the AudioConverter will
@@ -150,6 +149,7 @@ void AudioBufferConverter::ResetConverter(
       buffer->sample_rate() == output_params_.sample_rate()
           ? output_params_.frames_per_buffer()
           : SincResampler::kDefaultRequestSize);
+  input_params_.set_channels_for_discrete(buffer->channel_count());
 
   io_sample_rate_ratio_ = static_cast<double>(input_params_.sample_rate()) /
                           output_params_.sample_rate();