Move media/audio files into media namespace

media/audio/mac/audio_manager_mac.cc

Index: media/audio/mac/audio_manager_mac.cc
diff --git a/media/audio/mac/audio_manager_mac.cc b/media/audio/mac/audio_manager_mac.cc
index 3b1161d5d1e7cf352e51d6ac8448135f7b398197..2bd85018713331c8fa0941c19a9619ebea1b9fe8 100644
--- a/media/audio/mac/audio_manager_mac.cc
+++ b/media/audio/mac/audio_manager_mac.cc
@@ -15,6 +15,8 @@
 #include "media/audio/mac/audio_output_mac.h"
 #include "media/base/limits.h"
 
+namespace media {
+
 // Maximum number of output streams that can be open simultaneously.
 static const int kMaxOutputStreams = 50;
 
@@ -293,3 +295,5 @@ AudioInputStream* AudioManagerMac::MakeLowLatencyInputStream(
 AudioManager* CreateAudioManager() {
   return new AudioManagerMac();
 }
+
+}  // namespace media