[Sync] Plumb initial type set from engine to DTM.

components/sync/engine/fake_sync_engine.cc

Index: components/sync/engine/fake_sync_engine.cc
diff --git a/components/sync/engine/fake_sync_engine.cc b/components/sync/engine/fake_sync_engine.cc
index 969ea8910873db79d1591f0c4af115c33ecd6be8..141bed1ef0893417aaf21ce35bbf44a5f95eb68a 100644
--- a/components/sync/engine/fake_sync_engine.cc
+++ b/components/sync/engine/fake_sync_engine.cc
@@ -29,7 +29,7 @@ void FakeSyncEngine::Initialize(
     const base::Closure& report_unrecoverable_error_function,
     const HttpPostProviderFactoryGetter& http_post_provider_factory_getter,
     std::unique_ptr<SyncEncryptionHandler::NigoriState> saved_nigori_state) {
-  host->OnEngineInitialized(WeakHandle<JsBackend>(),
+  host->OnEngineInitialized(ModelTypeSet(), WeakHandle<JsBackend>(),
                             WeakHandle<DataTypeDebugInfoListener>(),
                             kTestCacheGuid, !fail_initial_download_);
 }