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

media/base/media_switches.h

Index: media/base/media_switches.h
diff --git a/media/base/media_switches.h b/media/base/media_switches.h
new file mode 100644
index 0000000000000000000000000000000000000000..4afa5201169f8dbebc03594f27f816662ca678f6
--- /dev/null
+++ b/media/base/media_switches.h
@@ -0,0 +1,20 @@
+// 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.
+
+// Defines all the "media" command-line switches.
+
+#ifndef MEDIA_BASE_SWITCHES_H_
+#define MEDIA_BASE_SWITCHES_H_
+
+#include "build/build_config.h"
+
+namespace switches {
+
+#if defined(OS_LINUX)
+extern const char kAlsaDevice[];
+#endif
+
+}  // namespace switches
+
+#endif  // MEDIA_BASE_SWITCHES_H_