Allow dynamic enabling/disabling of unified desktop

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 b73e65d8fcfe48ef47755b97e0dbbb167fbc0ad8..4bb070d438d581e5720c0ed9c53b17f1af399b53 100644
--- a/ash/test/display_manager_test_api.h
+++ b/ash/test/display_manager_test_api.h
@@ -34,8 +34,6 @@ class DisplayManagerTestApi {
   static bool TestIfMouseWarpsAt(ui::test::EventGenerator& event_generator,
                                  const gfx::Point& point_in_screen);
 
-  static void EnableUnifiedDesktopForTest();
-
   DisplayManagerTestApi();
   virtual ~DisplayManagerTestApi();