Move media/audio files into media namespace

media/audio/audio_manager_base.h

Index: media/audio/audio_manager_base.h
diff --git a/media/audio/audio_manager_base.h b/media/audio/audio_manager_base.h
index ba272217afcccd2906e48f3b45c460d9865d35b1..acb85b621eb5257d217214d3856e08cddd355e35 100644
--- a/media/audio/audio_manager_base.h
+++ b/media/audio/audio_manager_base.h
@@ -13,12 +13,14 @@
 #include "base/synchronization/lock.h"
 #include "media/audio/audio_manager.h"
 
-class AudioOutputDispatcher;
-
 namespace base {
 class Thread;
 }
 
+namespace media {
+
+class AudioOutputDispatcher;
+
 // AudioManagerBase provides AudioManager functions common for all platforms.
 class MEDIA_EXPORT AudioManagerBase : public AudioManager {
  public:
@@ -124,4 +126,6 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 };
 
+}  // namespace media
+
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_