[USS] Add function for update storage key for processor

components/sync/model/fake_model_type_change_processor.cc

Index: components/sync/model/fake_model_type_change_processor.cc
diff --git a/components/sync/model/fake_model_type_change_processor.cc b/components/sync/model/fake_model_type_change_processor.cc
index 9f418794a80b306a379de541bbe205100f265a3e..0c396655c628fdbd8e62a6e5d63e7a98b927a842 100644
--- a/components/sync/model/fake_model_type_change_processor.cc
+++ b/components/sync/model/fake_model_type_change_processor.cc
@@ -35,6 +35,11 @@ void FakeModelTypeChangeProcessor::Delete(
     const std::string& client_tag,
     MetadataChangeList* metadata_change_list) {}
 
+void FakeModelTypeChangeProcessor::UpdateStorageKey(
+    const std::string& old_storage_key,
+    const std::string& new_storage_key,
+    MetadataChangeList* metadata_change_list) {}
+
 void FakeModelTypeChangeProcessor::ModelReadyToSync(
     std::unique_ptr<MetadataBatch> batch) {}