Eliminate ash::internal namespace

ash/shelf/shelf_tooltip_manager.h

Index: ash/shelf/shelf_tooltip_manager.h
diff --git a/ash/shelf/shelf_tooltip_manager.h b/ash/shelf/shelf_tooltip_manager.h
index 5bb5f0966bb3a49c73c337ff0736e9ccfb3cd383..d7ca088610ceb6d0b6ea49df4bc430db84f0ed72 100644
--- a/ash/shelf/shelf_tooltip_manager.h
+++ b/ash/shelf/shelf_tooltip_manager.h
@@ -26,15 +26,14 @@ class Label;
 }
 
 namespace ash {
+class ShelfView;
+class ShelfLayoutManager;
+
 namespace test {
 class ShelfTooltipManagerTest;
 class ShelfViewTest;
 }
 
-namespace internal {
-class ShelfView;
-class ShelfLayoutManager;
-
 // ShelfTooltipManager manages the tooltip balloon poping up on shelf items.
 class ASH_EXPORT ShelfTooltipManager : public ui::EventHandler,
                                        public ShelfLayoutManagerObserver {
@@ -115,7 +114,6 @@ protected:
   DISALLOW_COPY_AND_ASSIGN(ShelfTooltipManager);
 };
 
-}  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_TOOLTIP_MANAGER_H_