Move media/audio files into media namespace

media/audio/mac/audio_manager_mac.h

Index: media/audio/mac/audio_manager_mac.h
diff --git a/media/audio/mac/audio_manager_mac.h b/media/audio/mac/audio_manager_mac.h
index d54f2936d323ed9acb194d5a65f258301e55f4a2..54ff3a6d3a995dfb6729d03f279ac09dedde555c 100644
--- a/media/audio/mac/audio_manager_mac.h
+++ b/media/audio/mac/audio_manager_mac.h
@@ -9,6 +9,8 @@
 #include "base/compiler_specific.h"
 #include "media/audio/audio_manager_base.h"
 
+namespace media {
+
 // Mac OS X implementation of the AudioManager singleton. This class is internal
 // to the audio output and only internal users can call methods not exposed by
 // the AudioManager class.
@@ -41,4 +43,6 @@ class MEDIA_EXPORT AudioManagerMac : public AudioManagerBase {
   DISALLOW_COPY_AND_ASSIGN(AudioManagerMac);
 };
 
+}  // namespace media
+
 #endif  // MEDIA_AUDIO_MAC_AUDIO_MANAGER_MAC_H_