Move media/audio files into media namespace

media/audio/linux/alsa_output.h

Index: media/audio/linux/alsa_output.h
diff --git a/media/audio/linux/alsa_output.h b/media/audio/linux/alsa_output.h
index ee257ebb391ceb4a34d2a938bbc270c5c056f346..0da7fade22c5feaf52a39684236307d6a159735f 100644
--- a/media/audio/linux/alsa_output.h
+++ b/media/audio/linux/alsa_output.h
@@ -32,13 +32,13 @@
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
 
+class MessageLoop;
+
 namespace media {
-class SeekableBuffer;
-};  // namespace media
 
 class AlsaWrapper;
 class AudioManagerLinux;
-class MessageLoop;
+class SeekableBuffer;
 
 class MEDIA_EXPORT AlsaPcmOutputStream : public AudioOutputStream {
  public:
@@ -210,4 +210,6 @@ class MEDIA_EXPORT AlsaPcmOutputStream : public AudioOutputStream {
 MEDIA_EXPORT std::ostream& operator<<(std::ostream& os,
                                       AlsaPcmOutputStream::InternalState);
 
+};  // namespace media
+
 #endif  // MEDIA_AUDIO_LINUX_ALSA_OUTPUT_H_