Move media/audio files into media namespace

media/audio/linux/alsa_input.h

Index: media/audio/linux/alsa_input.h
diff --git a/media/audio/linux/alsa_input.h b/media/audio/linux/alsa_input.h
index bbe965de030d0063fc2f1cdec02b3fdc18f93e10..70e79a0ff54a79b5a25ab1b101dea2ba47810d1c 100644
--- a/media/audio/linux/alsa_input.h
+++ b/media/audio/linux/alsa_input.h
@@ -16,6 +16,8 @@
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
 
+namespace media {
+
 class AlsaWrapper;
 class AudioManagerLinux;
 
@@ -84,4 +86,6 @@ class AlsaPcmInputStream : public AudioInputStream {
   DISALLOW_COPY_AND_ASSIGN(AlsaPcmInputStream);
 };
 
+}  // namespace media
+
 #endif  // MEDIA_AUDIO_LINUX_ALSA_INPUT_H_