Eliminate ash::internal namespace

ash/system/win/audio/tray_audio_win.cc

Index: ash/system/win/audio/tray_audio_win.cc
diff --git a/ash/system/win/audio/tray_audio_win.cc b/ash/system/win/audio/tray_audio_win.cc
index 0d2226c02523261c7cec25e64f164c9c9243dc69..c3205412b2145cfc2fd82f59323875c863d47eb2 100644
--- a/ash/system/win/audio/tray_audio_win.cc
+++ b/ash/system/win/audio/tray_audio_win.cc
@@ -11,8 +11,6 @@ namespace ash {
 using system::TrayAudioDelegate;
 using system::TrayAudioDelegateWin;
 
-namespace internal {
-
 TrayAudioWin::TrayAudioWin(SystemTray* system_tray)
     : TrayAudio(system_tray,
                 scoped_ptr<TrayAudioDelegate>(new TrayAudioDelegateWin())) {
@@ -21,5 +19,4 @@ TrayAudioWin::TrayAudioWin(SystemTray* system_tray)
 TrayAudioWin::~TrayAudioWin() {
 }
 
-}  // namespace internal
 }  // namespace ash