Eliminate ash::internal namespace

ash/first_run/desktop_cleaner.h

Index: ash/first_run/desktop_cleaner.h
diff --git a/ash/first_run/desktop_cleaner.h b/ash/first_run/desktop_cleaner.h
index c3077b42c2f60fba35b70436abaccc9b1750fc38..061f1120fe8c9564948f3ed94f4eb07cd2cfcb36 100644
--- a/ash/first_run/desktop_cleaner.h
+++ b/ash/first_run/desktop_cleaner.h
@@ -13,16 +13,13 @@
 #include "base/memory/scoped_ptr.h"
 
 namespace ash {
+class ContainerHider;
+class NotificationBlocker;
 
 namespace test {
 class FirstRunHelperTest;
 }
 
-namespace internal {
-
-class ContainerHider;
-class NotificationBlocker;
-
 // Class used to "clean" ash desktop, i.e. hide all windows and notifications.
 class ASH_EXPORT DesktopCleaner {
  public:
@@ -40,7 +37,6 @@ class ASH_EXPORT DesktopCleaner {
   DISALLOW_COPY_AND_ASSIGN(DesktopCleaner);
 };
 
-}  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_FIRST_RUN_DESKTOP_CLEANER_