Delete WindowManagerWindowTreeFactorySetTestApi.

services/ui/ws/cursor_unittest.cc

Index: services/ui/ws/cursor_unittest.cc
diff --git a/services/ui/ws/cursor_unittest.cc b/services/ui/ws/cursor_unittest.cc
index cc44915b8064af314738c00ae9a2a7114a90d296..a3f59444200db61faa16f4b44407e36940807fdc 100644
--- a/services/ui/ws/cursor_unittest.cc
+++ b/services/ui/ws/cursor_unittest.cc
@@ -52,9 +52,7 @@ class CursorTest : public testing::Test {
     window_server_delegate()->CreateDisplays(1);
 
     // As a side effect, this allocates Displays.
-    WindowManagerWindowTreeFactorySetTestApi(
-        window_server()->window_manager_window_tree_factory_set())
-        .Add(kTestId1);
+    AddWindowManager(window_server(), kTestId1);
     window_server()->user_id_tracker()->AddUserId(kTestId1);
     window_server()->user_id_tracker()->SetActiveUserId(kTestId1);
   }