[Sync] Let ModelTypeRegistry filter out initial download USS types.

components/sync/engine_impl/sync_manager_impl.cc

Index: components/sync/engine_impl/sync_manager_impl.cc
diff --git a/components/sync/engine_impl/sync_manager_impl.cc b/components/sync/engine_impl/sync_manager_impl.cc
index 7a3466d019f9677252cc1452e80be7f5d712afa6..471bafc175996efcb08fc4a83b808b5289e0e62e 100644
--- a/components/sync/engine_impl/sync_manager_impl.cc
+++ b/components/sync/engine_impl/sync_manager_impl.cc
@@ -194,6 +194,10 @@ void SyncManagerImpl::ConfigureSyncer(
   DCHECK(!ready_task.is_null());
   DCHECK(initialized_);
 
+  // Don't download non-blocking types that have already completed initial sync.
+  to_download.RemoveAll(
+      model_type_registry_->GetInitialSyncDoneNonBlockingTypes());
+
   DVLOG(1) << "Configuring -"
            << "\n\t"
            << "current types: "