Revert of [Sync] Make directory types registration explicit in ModelTypeRegistry

components/sync/engine_impl/cycle/sync_cycle_context.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.
 
 #include "components/sync/engine_impl/cycle/sync_cycle_context.h"
 
 #include "components/sync/base/extensions_activity.h"
 
 namespace syncer {
 
@@ skipping 25 matching lines @@
   for (it = listeners.begin(); it != listeners.end(); ++it)
     listeners_.AddObserver(*it);
 }
 
 SyncCycleContext::~SyncCycleContext() {}
 
 ModelTypeSet SyncCycleContext::GetEnabledTypes() const {
   return model_type_registry_->GetEnabledTypes();
 }
 
+void SyncCycleContext::SetRoutingInfo(
+    const ModelSafeRoutingInfo& routing_info) {
+  model_type_registry_->SetEnabledDirectoryTypes(routing_info);
+}
+
 }  // namespace syncer