Fix incorrect AudioConverter setup for discrete channel layouts.

media/base/audio_converter.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.
 //
 // AudioConverter implementation.  Uses MultiChannelSincResampler for resampling
 // audio, ChannelMixer for channel mixing, and AudioPullFifo for buffering.
 //
 // Delay estimates are provided to InputCallbacks based on the frame delay
 // information reported via the resampler and FIFO units.
 
@@ skipping 15 matching lines @@
                                const AudioParameters& output_params,
                                bool disable_fifo)
     : chunk_size_(input_params.frames_per_buffer()),
       downmix_early_(false),
       resampler_frame_delay_(0),
       input_channel_count_(input_params.channels()) {
   CHECK(input_params.IsValid());
   CHECK(output_params.IsValid());
 
   // Handle different input and output channel layouts.
-  if (input_params.channel_layout() != output_params.channel_layout()) {
+  if (input_params.channel_layout() != output_params.channel_layout() ||
+      input_params.channels() != output_params.channels()) {
     DVLOG(1) << "Remixing channel layout from " << input_params.channel_layout()
              << " to " << output_params.channel_layout() << "; from "
              << input_params.channels() << " channels to "
              << output_params.channels() << " channels.";
     channel_mixer_.reset(new ChannelMixer(input_params, output_params));
 
     // Pare off data as early as we can for efficiency.
     downmix_early_ = input_params.channels() > output_params.channels();
   }
 
@@ skipping 195 matching lines @@
   else
     SourceCallback(0, dest);
 }
 
 void AudioConverter::CreateUnmixedAudioIfNecessary(int frames) {
   if (!unmixed_audio_ || unmixed_audio_->frames() != frames)
     unmixed_audio_ = AudioBus::Create(input_channel_count_, frames);
 }
 
 }  // namespace media