Fix chromeos=1 so Pulse is preferred when use_cras=0.

media/audio/cras/audio_manager_cras.cc

 // Copyright 2013 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/cras/audio_manager_cras.h"
 
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/logging.h"
 #include "base/nix/xdg_util.h"
@@ skipping 120 matching lines @@
 AudioOutputStream* AudioManagerCras::MakeOutputStream(
     const AudioParameters& params) {
   return new CrasUnifiedStream(params, this);
 }
 
 AudioInputStream* AudioManagerCras::MakeInputStream(
     const AudioParameters& params, const std::string& device_id) {
   return new CrasInputStream(params, this, device_id);
 }
 
+snd_pcm_format_t AudioManagerCras::BitsToFormat(int bits_per_sample) {
+  switch (bits_per_sample) {
+    case 8:
+      return SND_PCM_FORMAT_U8;
+    case 16:
+      return SND_PCM_FORMAT_S16;
+    case 24:
+      return SND_PCM_FORMAT_S24;
+    case 32:
+      return SND_PCM_FORMAT_S32;
+    default:
+      return SND_PCM_FORMAT_UNKNOWN;
+  }
+}
+
 }  // namespace media