Eliminate ash::internal namespace

ash/wm/maximize_mode/maximize_mode_window_manager.h

Index: ash/wm/maximize_mode/maximize_mode_window_manager.h
diff --git a/ash/wm/maximize_mode/maximize_mode_window_manager.h b/ash/wm/maximize_mode/maximize_mode_window_manager.h
index 0c51cb3ba0c2b87025b8745e545bc28be601255b..fb1e693733c04d5eaad47dd9c29a418fb6f9617b 100644
--- a/ash/wm/maximize_mode/maximize_mode_window_manager.h
+++ b/ash/wm/maximize_mode/maximize_mode_window_manager.h
@@ -17,10 +17,8 @@
 #include "ui/gfx/display_observer.h"
 
 namespace ash {
-class Shell;
-
-namespace internal{
 class MaximizeModeWindowState;
+class Shell;
 
 // A window manager which - when created - will force all windows into maximized
 // mode. Exception are panels and windows which cannot be maximized.
@@ -114,7 +112,6 @@ class ASH_EXPORT MaximizeModeWindowManager : public aura::WindowObserver,
   DISALLOW_COPY_AND_ASSIGN(MaximizeModeWindowManager);
 };
 
-}  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_MAXIMIZE_MODE_MAXIMIZE_MODE_WINDOW_MANAGER_H_