Make it possible to build without enable_supervised_users.

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 1874c5fb1d09c234a30c9697702529bd5b85ae9e..1fa2e3ade16c1abc51eb9436f0a75af3ff2f0759 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -261,8 +261,6 @@ split_static_library("browser") {
     "component_updater/sth_set_component_installer.h",
     "component_updater/subresource_filter_component_installer.cc",
     "component_updater/subresource_filter_component_installer.h",
-    "component_updater/supervised_user_whitelist_installer.cc",
-    "component_updater/supervised_user_whitelist_installer.h",
     "component_updater/sw_reporter_installer_win.cc",
     "component_updater/sw_reporter_installer_win.h",
     "conflicts/installed_programs_win.cc",
@@ -1349,8 +1347,6 @@ split_static_library("browser") {
     "sync/sessions/sync_sessions_web_contents_router.h",
     "sync/sessions/sync_sessions_web_contents_router_factory.cc",
     "sync/sessions/sync_sessions_web_contents_router_factory.h",
-    "sync/supervised_user_signin_manager_wrapper.cc",
-    "sync/supervised_user_signin_manager_wrapper.h",
     "sync/sync_startup_tracker.cc",
     "sync/sync_startup_tracker.h",
     "sync/user_event_service_factory.cc",
@@ -3282,10 +3278,14 @@ split_static_library("browser") {
 
     if (enable_supervised_users) {
       sources += [
+        "component_updater/supervised_user_whitelist_installer.cc",
+        "component_updater/supervised_user_whitelist_installer.h",
         "supervised_user/child_accounts/child_account_feedback_reporter_android.cc",
         "supervised_user/child_accounts/child_account_feedback_reporter_android.h",
         "supervised_user/child_accounts/child_account_service_android.cc",
         "supervised_user/child_accounts/child_account_service_android.h",
+        "sync/supervised_user_signin_manager_wrapper.cc",
+        "sync/supervised_user_signin_manager_wrapper.h",
       ]
     }
   } else {