face: ProtocolFactory registry

refs #3904

Change-Id: Ic7c8b3d6138b7c27d4189a2e15cc646055ad1294
diff --git a/tests/daemon/face/factory-test-common.hpp b/tests/daemon/face/factory-test-common.hpp
index 0c67586..8622d06 100644
--- a/tests/daemon/face/factory-test-common.hpp
+++ b/tests/daemon/face/factory-test-common.hpp
@@ -31,6 +31,7 @@
 #include "tests/test-common.hpp"
 
 namespace nfd {
+namespace face {
 namespace tests {
 
 struct CreateFaceExpectedResult
@@ -76,6 +77,7 @@
 }
 
 } // namespace tests
+} // namespace face
 } // namespace nfd
 
 #endif // NFD_TESTS_DAEMON_FACE_FACTORY_TEST_COMMON_HPP