Sync: Support multiple setup UIs.

chrome/browser/supervised_user/supervised_user_service.cc

Index: chrome/browser/supervised_user/supervised_user_service.cc
diff --git a/chrome/browser/supervised_user/supervised_user_service.cc b/chrome/browser/supervised_user/supervised_user_service.cc
index 0f71827875aeaaebb3c71482ecd4956c8741e3f2..44a1d4a857781ea2fd860d2653d90e28e2e2bff9 100644
--- a/chrome/browser/supervised_user/supervised_user_service.cc
+++ b/chrome/browser/supervised_user/supervised_user_service.cc
@@ -682,7 +682,8 @@ void SupervisedUserService::SetupSync() {
 void SupervisedUserService::StartSetupSync() {
   // Tell the sync service that setup is in progress so we don't start syncing
   // until we've finished configuration.
-  ProfileSyncServiceFactory::GetForProfile(profile_)->SetSetupInProgress(true);
+  sync_blocker_ = ProfileSyncServiceFactory::GetForProfile(profile_)
+                      ->GetSetupInProgressHandle();
 }
 
 void SupervisedUserService::FinishSetupSyncWhenReady() {
@@ -712,7 +713,7 @@ void SupervisedUserService::FinishSetupSync() {
   service->OnUserChoseDatatypes(sync_everything, synced_datatypes);
 
   // Notify ProfileSyncService that we are done with configuration.
-  service->SetSetupInProgress(false);
+  sync_blocker_.reset();
   service->SetFirstSetupComplete();
 }
 #endif