Move Alsa device opening into the audio thread, and add in support for multi-channel audio.

media/audio/mac/audio_output_mac.cc

 // Copyright (c) 2009 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/mac/audio_manager_mac.h"
 #include "media/audio/mac/audio_output_mac.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "media/audio/audio_util.h"
@@ skipping 153 matching lines @@
   if (!audio_queue_)
     return;
   *left_level = volume_;
   *right_level = volume_;
 }
 
 // Reorder PCM from AAC layout to Core Audio layout.
 // TODO(fbarchard): Switch layout when ffmpeg is updated.
 namespace {
 template<class Format>
-static void SwizzleLayout(Format *b, size_t filled) {
+static void SwizzleLayout(Format* b, size_t filled) {
   static const int kNumSurroundChannels = 6;
   Format aac[kNumSurroundChannels];
   for (size_t i = 0; i < filled; i += sizeof(aac), b += kNumSurroundChannels) {
     memcpy(aac, b, sizeof(aac));
     b[0] = aac[1];  // L
     b[1] = aac[2];  // R
     b[2] = aac[0];  // C
     b[3] = aac[5];  // LFE
     b[4] = aac[3];  // Ls
     b[5] = aac[4];  // Rs
@@ skipping 82 matching lines @@
       HandleError(err);
       return;
     }
   }
   err  = AudioQueueStart(audio_queue_, NULL);
   if (err != noErr) {
     HandleError(err);
     return;
   }
 }
-