/usr/include/google/protobuf/stubs/ is in libprotobuf-dev 2.6.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/google/protobuf/stubs/atomicops.h
/usr/include/google/protobuf/stubs/atomicops_internals_arm64_gcc.h
/usr/include/google/protobuf/stubs/atomicops_internals_arm_gcc.h
/usr/include/google/protobuf/stubs/atomicops_internals_arm_qnx.h
/usr/include/google/protobuf/stubs/atomicops_internals_atomicword_compat.h
/usr/include/google/protobuf/stubs/atomicops_internals_generic_gcc.h
/usr/include/google/protobuf/stubs/atomicops_internals_macosx.h
/usr/include/google/protobuf/stubs/atomicops_internals_mips_gcc.h
/usr/include/google/protobuf/stubs/atomicops_internals_pnacl.h
/usr/include/google/protobuf/stubs/atomicops_internals_solaris.h
/usr/include/google/protobuf/stubs/atomicops_internals_tsan.h
/usr/include/google/protobuf/stubs/atomicops_internals_x86_gcc.h
/usr/include/google/protobuf/stubs/atomicops_internals_x86_msvc.h
/usr/include/google/protobuf/stubs/common.h
/usr/include/google/protobuf/stubs/once.h
/usr/include/google/protobuf/stubs/platform_macros.h
/usr/include/google/protobuf/stubs/stl_util.h
/usr/include/google/protobuf/stubs/template_util.h
/usr/include/google/protobuf/stubs/type_traits.h