Separate ash::test::DisplayManagerTestApi from ash

ash/display/mouse_cursor_event_filter.h

Index: ash/display/mouse_cursor_event_filter.h
diff --git a/ash/display/mouse_cursor_event_filter.h b/ash/display/mouse_cursor_event_filter.h
index 049f9b9c455dda63994c9441c4da6d1b04966684..c507a1d596080d097df9b6cd5aaa11010f0bda3c 100644
--- a/ash/display/mouse_cursor_event_filter.h
+++ b/ash/display/mouse_cursor_event_filter.h
@@ -24,6 +24,10 @@ namespace ash {
 class DisplayEdgeController;
 class MouseWarpController;
 
+namespace test {
+class AshTestBase;
+}
+
 // An event filter that controls mouse location in extended desktop
 // environment.
 class ASH_EXPORT MouseCursorEventFilter
@@ -48,7 +52,7 @@ class ASH_EXPORT MouseCursorEventFilter
   void OnMouseEvent(ui::MouseEvent* event) override;
 
  private:
-  friend class test::DisplayManagerTestApi;
+  friend class test::AshTestBase;
   friend class ExtendedMouseWarpControllerTest;
   friend class MouseCursorEventFilterTest;
   friend class UnifiedMouseWarpControllerTest;