Mix to an intermediate buffer.

services/media/audio/BUILD.gn

 # Copyright 2015 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.
 
 import("//mojo/public/mojo_application.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
 group("audio") {
   deps = [
     ":audio_server",
@@ skipping 15 matching lines @@
     "audio_output_manager.cc",
     "audio_pipe.cc",
     "audio_server_app.cc",
     "audio_server_impl.cc",
     "audio_track_impl.cc",
     "audio_track_to_output_link.cc",
     "platform/generic/mixer.cc",
     "platform/generic/mixers/linear_sampler.cc",
     "platform/generic/mixers/no_op.cc",
     "platform/generic/mixers/point_sampler.cc",
+    "platform/generic/output_formatter.cc",
     "platform/generic/standard_output_base.cc",
     "platform/generic/throttle_output.cc",
   ]
 
   libs = []
 
   if (is_linux && !is_fnl && !is_android) {
     sources += [ "platform/linux/alsa_output.cc" ]
     libs += [ "asound" ]
   } else {
     sources += [ "platform/stubs/alsa_output_stub.cc" ]
   }
 }