sync: Introduce ModelTypeRegistry and helpers

sync/sessions/sync_session_unittest.cc

Index: sync/sessions/sync_session_unittest.cc
diff --git a/sync/sessions/sync_session_unittest.cc b/sync/sessions/sync_session_unittest.cc
index e712552f580679d48d753d5010495583d7f0df18..09a6851b07863d6dc690f04127f208bb6aec35da 100644
--- a/sync/sessions/sync_session_unittest.cc
+++ b/sync/sessions/sync_session_unittest.cc
@@ -54,19 +54,21 @@ class SyncSessionTest : public testing::Test,
     std::vector<ModelSafeWorker*> workers;
     GetWorkers(&workers);
 
+    model_type_registry_.reset(new ModelTypeRegistry(NULL, workers));
+
     context_.reset(
         new SyncSessionContext(
             NULL,
             NULL,
-            workers,
             extensions_activity_.get(),
             std::vector<SyncEngineEventListener*>(),
             NULL,
             NULL,
+            model_type_registry_.get(),
             true,  // enable keystore encryption
             false,  // force enable pre-commit GU avoidance experiment
             "fake_invalidator_client_id"));
-    context_->set_routing_info(routes_);
+    context_->SetRoutingInfo(routes_);
 
     session_.reset(MakeSession());
   }
@@ -139,6 +141,7 @@ class SyncSessionTest : public testing::Test,
   base::MessageLoop message_loop_;
   bool controller_invocations_allowed_;
   scoped_ptr<SyncSession> session_;
+  scoped_ptr<ModelTypeRegistry> model_type_registry_;
   scoped_ptr<SyncSessionContext> context_;
   std::vector<scoped_refptr<ModelSafeWorker> > workers_;
   ModelSafeRoutingInfo routes_;