[sync] Set up notification-free infra for triggering local sync refresh

chrome/browser/sync/profile_sync_service.cc

Index: chrome/browser/sync/profile_sync_service.cc
diff --git a/chrome/browser/sync/profile_sync_service.cc b/chrome/browser/sync/profile_sync_service.cc
index 14126fbbde159391c54251595fe085f0abf542f1..6e13e6eaaea9f49fa34d6e6867afe14012fe263f 100644
--- a/chrome/browser/sync/profile_sync_service.cc
+++ b/chrome/browser/sync/profile_sync_service.cc
@@ -1688,6 +1688,11 @@ bool ProfileSyncService::IsSyncActive() const {
          data_type_manager_->state() != DataTypeManager::STOPPED;
 }
 
+void ProfileSyncService::TriggerRefresh(const syncer::ModelTypeSet& types) {
+  if (backend_initialized_)
+    backend_->TriggerRefresh(types);
+}
+
 bool ProfileSyncService::IsSignedIn() const {
   // Sync is logged in if there is a non-empty effective account id.
   return !signin_->GetAccountIdToUse().empty();