[Chromoting] Update comments in AudioCapturerWin

remoting/host/audio_capturer_win.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 "remoting/host/audio_capturer_win.h"
 
 #include <avrt.h>
 #include <mmreg.h>
 #include <mmsystem.h>
 #include <objbase.h>
@@ skipping 256 matching lines @@
       break;
 
     if (volume_filter_.Apply(reinterpret_cast<int16_t*>(data), frames)) {
       std::unique_ptr<AudioPacket> packet(new AudioPacket());
       packet->add_data(data, frames * wave_format_ex_->nBlockAlign);
       packet->set_encoding(AudioPacket::ENCODING_RAW);
       packet->set_sampling_rate(sampling_rate_);
       packet->set_bytes_per_sample(AudioPacket::BYTES_PER_SAMPLE_2);
       // Only the count of channels is taken into account now, we should also
       // consider dwChannelMask.
-      // TODO(zijiehe): Support also layouts.
+      // TODO(zijiehe): Convert dwChannelMask to layout and pass it to
+      // AudioPump. So the stream can be downmixed properly with both number and
+      // layouts of speakers.
       packet->set_channels(static_cast<AudioPacket::Channels>(
           wave_format_ex_->nChannels));
 
       callback_.Run(std::move(packet));
     }
 
     hr = audio_capture_client_->ReleaseBuffer(frames);
     if (FAILED(hr))
       break;
   }
@@ skipping 13 matching lines @@
 
 bool AudioCapturer::IsSupported() {
   return true;
 }
 
 std::unique_ptr<AudioCapturer> AudioCapturer::Create() {
   return base::WrapUnique(new AudioCapturerWin());
 }
 
 }  // namespace remoting