Move session service and supervised users to buildflags.

chrome/browser/prefs/chrome_pref_service_factory.cc

Index: chrome/browser/prefs/chrome_pref_service_factory.cc
diff --git a/chrome/browser/prefs/chrome_pref_service_factory.cc b/chrome/browser/prefs/chrome_pref_service_factory.cc
index f27aafb2b7e86610bea60233afe4cfc5ac156358..fe58fc30c7a23bad5cd0d18484b1795fe25f9752 100644
--- a/chrome/browser/prefs/chrome_pref_service_factory.cc
+++ b/chrome/browser/prefs/chrome_pref_service_factory.cc
@@ -28,6 +28,7 @@
 #include "chrome/browser/sync/glue/sync_start_util.h"
 #include "chrome/browser/ui/profile_error_dialog.h"
 #include "chrome/common/chrome_constants.h"
+#include "chrome/common/features.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/grit/browser_resources.h"
 #include "chrome/grit/chromium_strings.h"
@@ -64,7 +65,7 @@
 #include "extensions/browser/pref_names.h"
 #endif
 
-#if defined(ENABLE_SUPERVISED_USERS)
+#if BUILDFLAG(ENABLE_SUPERVISED_USERS)
 #include "chrome/browser/supervised_user/supervised_user_pref_store.h"
 #endif
 
@@ -428,7 +429,7 @@ void PrepareFactory(sync_preferences::PrefServiceSyncableFactory* factory,
   factory->SetManagedPolicies(policy_service, policy_connector);
   factory->SetRecommendedPolicies(policy_service, policy_connector);
 
-#if defined(ENABLE_SUPERVISED_USERS)
+#if BUILDFLAG(ENABLE_SUPERVISED_USERS)
   if (supervised_user_settings) {
     scoped_refptr<PrefStore> supervised_user_prefs = make_scoped_refptr(
         new SupervisedUserPrefStore(supervised_user_settings));