Eliminate ash::internal namespace

ash/wm/overview/window_selector_controller.h

Index: ash/wm/overview/window_selector_controller.h
diff --git a/ash/wm/overview/window_selector_controller.h b/ash/wm/overview/window_selector_controller.h
index 2bd9697a31a4cf81d6b37abd0c93e5743343c2f5..18104f8c0336c85dac25dd23cfaaedc99a4003af 100644
--- a/ash/wm/overview/window_selector_controller.h
+++ b/ash/wm/overview/window_selector_controller.h
@@ -21,12 +21,8 @@ class Window;
 }
 
 namespace ash {
-
-namespace internal {
-class WindowSelectorTest;
-}
-
 class WindowSelector;
+class WindowSelectorTest;
 
 // Manages a window selector which displays an overview of all windows and
 // allows selecting a window to activate it.
@@ -58,7 +54,7 @@ class ASH_EXPORT WindowSelectorController
   virtual void OnSelectionCanceled() OVERRIDE;
 
  private:
-  friend class internal::WindowSelectorTest;
+  friend class WindowSelectorTest;
 
   // Dispatched when window selection begins.
   void OnSelectionStarted();