Move media/audio files into media namespace (relanding)

media/audio/android/audio_track_output_android.cc

Index: media/audio/android/audio_track_output_android.cc
diff --git a/media/audio/android/audio_track_output_android.cc b/media/audio/android/audio_track_output_android.cc
index d65ff193bcf9aee5737069ff7a2e7d1680c648b9..7342750c5781ca8efb7aa32812cb106235d68ca3 100644
--- a/media/audio/android/audio_track_output_android.cc
+++ b/media/audio/android/audio_track_output_android.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -12,6 +12,8 @@
 using base::android::AttachCurrentThread;
 using base::android::CheckException;
 
+namespace media {
+
 static const int kTimerIntervalInMilliseconds = 50;
 
 class AudioTrackOutputStream::StreamBuffer {
@@ -309,3 +311,5 @@ void AudioTrackOutputStream::FillAudioBufferTask() {
   CheckException(env);
   env->DeleteLocalRef(buf);
 }
+
+}  // namespace media