Make it possible to build without enable_supervised_users.

chrome/test/base/testing_profile.h

Index: chrome/test/base/testing_profile.h
diff --git a/chrome/test/base/testing_profile.h b/chrome/test/base/testing_profile.h
index 2384f0c602a94dd3adae1add3b7d2d512ff7d772..746766b659ee4b12bf618f38f6f6e63ec2df1325 100644
--- a/chrome/test/base/testing_profile.h
+++ b/chrome/test/base/testing_profile.h
@@ -15,6 +15,7 @@
 #include "base/memory/ref_counted.h"
 #include "build/build_config.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/common/features.h"
 #include "components/domain_reliability/clear_mode.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 #include "extensions/features/features.h"
@@ -380,9 +381,11 @@ class TestingProfile : public Profile {
   // Creates a TestingPrefService and associates it with the TestingProfile.
   void CreateTestingPrefService();
 
+#if BUILDFLAG(ENABLE_SUPERVISED_USERS)
   // Creates a pref service that uses SupervisedUserPrefStore and associates
   // it with the TestingProfile.
   void CreatePrefServiceForSupervisedUser();
+#endif
 
   // Initializes |prefs_| for an incognito profile, derived from
   // |original_profile_|.