Move media/audio files into media namespace

media/audio/linux/audio_manager_linux.h

Index: media/audio/linux/audio_manager_linux.h
diff --git a/media/audio/linux/audio_manager_linux.h b/media/audio/linux/audio_manager_linux.h
index 81e53c4a46febc3bc0b15ed27ce4556e3d086eca..d62d3610b1248d98dfd69db7745fa3297059f7dd 100644
--- a/media/audio/linux/audio_manager_linux.h
+++ b/media/audio/linux/audio_manager_linux.h
@@ -11,6 +11,8 @@
 #include "base/threading/thread.h"
 #include "media/audio/audio_manager_base.h"
 
+namespace media {
+
 class AlsaWrapper;
 
 class MEDIA_EXPORT AudioManagerLinux : public AudioManagerBase {
@@ -73,4 +75,6 @@ class MEDIA_EXPORT AudioManagerLinux : public AudioManagerBase {
   DISALLOW_COPY_AND_ASSIGN(AudioManagerLinux);
 };
 
+}  // namespace media
+
 #endif  // MEDIA_AUDIO_LINUX_AUDIO_MANAGER_LINUX_H_