Move media/audio files into media namespace

media/audio/linux/alsa_output.cc

Index: media/audio/linux/alsa_output.cc
diff --git a/media/audio/linux/alsa_output.cc b/media/audio/linux/alsa_output.cc
index 8ba86df6f6677ab2cc7bf1de82d04c21a0241610..19823afc30ce9d5642bd28633a55d4c7be13e3d9 100644
--- a/media/audio/linux/alsa_output.cc
+++ b/media/audio/linux/alsa_output.cc
@@ -49,6 +49,8 @@
 #include "media/base/data_buffer.h"
 #include "media/base/seekable_buffer.h"
 
+namespace media {
+
 // Amount of time to wait if we've exhausted the data source.  This is to avoid
 // busy looping.
 static const uint32 kNoDataSleepMilliseconds = 10;
@@ -797,3 +799,5 @@ void AlsaPcmOutputStream::set_source_callback(AudioSourceCallback* callback) {
   DCHECK(IsOnAudioThread());
   source_callback_ = callback;
 }
+
+}  // namespace media