Make SyncBackendRegistrar aware of loaded data

sync/engine/syncer_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Syncer unit tests. Unfortunately a lot of these tests
 // are outdated and need to be reworked and updated.
 
 #include <algorithm>
 #include <limits>
 #include <list>
@@ skipping 217 matching lines @@
     ModelSafeRoutingInfo routing_info;
     std::vector<ModelSafeWorker*> workers;
 
     GetModelSafeRoutingInfo(&routing_info);
     GetWorkers(&workers);
 
     throttled_data_type_tracker_.reset(new ThrottledDataTypeTracker(NULL));
 
     context_.reset(
         new SyncSessionContext(
-            mock_server_.get(), directory(), routing_info, workers,
+            mock_server_.get(), directory(), workers,
             &extensions_activity_monitor_, throttled_data_type_tracker_.get(),
             listeners, NULL, &traffic_recorder_));
+    context_->set_routing_info(routing_info);
     ASSERT_FALSE(context_->resolver());
     syncer_ = new Syncer();
     session_.reset(MakeSession());
 
     syncable::ReadTransaction trans(FROM_HERE, directory());
     syncable::Directory::ChildHandles children;
     directory()->GetChildHandlesById(&trans, trans.root_id(), &children);
     ASSERT_EQ(0u, children.size());
     saw_syncer_event_ = false;
     root_id_ = TestIdFactory::root();
@@ skipping 4572 matching lines @@
 
 TEST_F(SyncerPositionTiebreakingTest, MidLowHigh) {
   Add(mid_id_);
   Add(low_id_);
   Add(high_id_);
   SyncShareNudge();
   ExpectLocalOrderIsByServerId();
 }
 
 }  // namespace syncer