Eliminate ash::internal namespace

ash/system/chromeos/system_clock_observer.cc

Index: ash/system/chromeos/system_clock_observer.cc
diff --git a/ash/system/chromeos/system_clock_observer.cc b/ash/system/chromeos/system_clock_observer.cc
index c5ab20c3d51a7008764d29231a6fa557eb32d557..d154d5eda2e6101b9603473ac5c77193aae5f0b7 100644
--- a/ash/system/chromeos/system_clock_observer.cc
+++ b/ash/system/chromeos/system_clock_observer.cc
@@ -9,7 +9,6 @@
 #include "chromeos/dbus/dbus_thread_manager.h"
 
 namespace ash {
-namespace internal {
 
 SystemClockObserver::SystemClockObserver() {
   chromeos::DBusThreadManager::Get()->GetSystemClockClient()
@@ -32,5 +31,4 @@ void SystemClockObserver::TimezoneChanged(const icu::TimeZone& timezone) {
   Shell::GetInstance()->system_tray_notifier()->NotifyRefreshClock();
 }
 
-}  // namespace internal
 }  // namespace ash