Move media/audio files into media namespace (relanding)

media/audio/simple_sources.h

Index: media/audio/simple_sources.h
diff --git a/media/audio/simple_sources.h b/media/audio/simple_sources.h
index a4373a09dd06039381975e744eee4cf9b6ee55c7..fa06857f13d7e3f60d83d0ec4f4c43b0fc2d741d 100644
--- a/media/audio/simple_sources.h
+++ b/media/audio/simple_sources.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -10,6 +10,8 @@
 #include "media/audio/audio_io.h"
 #include "media/base/seekable_buffer.h"
 
+namespace media {
+
 // An audio source that produces a pure sinusoidal tone.
 class MEDIA_EXPORT SineWaveAudioSource
     : public AudioOutputStream::AudioSourceCallback {
@@ -88,4 +90,6 @@ class MEDIA_EXPORT PushSource
   media::SeekableBuffer buffer_;
 };
 
+}  // namespace media
+
 #endif  // MEDIA_AUDIO_SIMPLE_SOURCES_H_