[USS] Change the place where SharedModelTypeProcessor got created

sync/api/model_type_service.cc

Index: sync/api/model_type_service.cc
diff --git a/sync/api/model_type_service.cc b/sync/api/model_type_service.cc
index 87df14bf6011dc559b98e90082d0e2d29f1235d7..1918db98e45a465e7fd9909367b0b9fa586da17c 100644
--- a/sync/api/model_type_service.cc
+++ b/sync/api/model_type_service.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "sync/api/model_type_service.h"
+#include "sync/internal_api/public/shared_model_type_processor.h"
 
 namespace syncer_v2 {
 
@@ -14,13 +15,17 @@ ModelTypeChangeProcessor* ModelTypeService::change_processor() const {
   return change_processor_.get();
 }
 
-void ModelTypeService::set_change_processor(
-    scoped_ptr<ModelTypeChangeProcessor> change_processor) {
-  DCHECK(!change_processor_);
-  change_processor_.swap(change_processor);
+void ModelTypeService::InitializeProcessor(syncer::ModelType type) {
+  DCHECK(!change_processor_.get());
+  change_processor_.reset(CreateSharedModelTypeProcessor(type).release());
   OnChangeProcessorSet();
 }
 
+scoped_ptr<SharedModelTypeProcessor>
+ModelTypeService::CreateSharedModelTypeProcessor(syncer::ModelType type) {
+  return make_scoped_ptr(new syncer_v2::SharedModelTypeProcessor(type, this));
+}
+
 void ModelTypeService::clear_change_processor() {
   change_processor_.reset();
 }