Eliminate ash::internal namespace

ash/test/display_manager_test_api.h

Index: ash/test/display_manager_test_api.h
diff --git a/ash/test/display_manager_test_api.h b/ash/test/display_manager_test_api.h
index db47ab31765905914c99535065a7ff2229606292..6c5d565ce34d0fef8c1a9bd6033ada611ba37fc6 100644
--- a/ash/test/display_manager_test_api.h
+++ b/ash/test/display_manager_test_api.h
@@ -12,15 +12,13 @@
 #include "ui/display/display_constants.h"
 
 namespace ash {
-namespace internal {
 class DisplayManager;
-}  // internal
 
 namespace test {
 
 class DisplayManagerTestApi {
  public:
-  explicit DisplayManagerTestApi(internal::DisplayManager* display_manager);
+  explicit DisplayManagerTestApi(DisplayManager* display_manager);
   virtual ~DisplayManagerTestApi();
 
   // Update the display configuration as given in |display_specs|. The format of
@@ -42,7 +40,7 @@ class DisplayManagerTestApi {
       const std::vector<ui::ColorCalibrationProfile>& profiles);
 
  private:
-  internal::DisplayManager* display_manager_;  // not owned
+  DisplayManager* display_manager_;  // not owned
 
   DISALLOW_COPY_AND_ASSIGN(DisplayManagerTestApi);
 };