[Sync] Start implementation of migration for USS.

components/sync/engine_impl/model_type_worker_unittest.cc

Index: components/sync/engine_impl/model_type_worker_unittest.cc
diff --git a/components/sync/engine_impl/model_type_worker_unittest.cc b/components/sync/engine_impl/model_type_worker_unittest.cc
index ca1cc97cd78986ca0ed4dd035bc9cc5ed6c7d575..dc2fbc3f697c292c051dfd3806f1c556d478666c 100644
--- a/components/sync/engine_impl/model_type_worker_unittest.cc
+++ b/components/sync/engine_impl/model_type_worker_unittest.cc
@@ -190,7 +190,8 @@ class ModelTypeWorkerTest : public ::testing::Test {
 
     // TODO(maxbogue): crbug.com/529498: Inject pending updates somehow.
     worker_ = base::MakeUnique<ModelTypeWorker>(
-        kModelType, state, std::move(cryptographer_copy), &mock_nudge_handler_,
+        kModelType, state, !state.initial_sync_done(),
+        std::move(cryptographer_copy), &mock_nudge_handler_,
         std::move(processor));
   }