/usr/include/json-glib-1.0/ is in libjson-glib-dev 1.1.2-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/json-glib-1.0/json-glib/
/usr/include/json-glib-1.0/json-glib/json-builder.h
/usr/include/json-glib-1.0/json-glib/json-enum-types.h
/usr/include/json-glib-1.0/json-glib/json-generator.h
/usr/include/json-glib-1.0/json-glib/json-glib.h
/usr/include/json-glib-1.0/json-glib/json-gobject.h
/usr/include/json-glib-1.0/json-glib/json-gvariant.h
/usr/include/json-glib-1.0/json-glib/json-parser.h
/usr/include/json-glib-1.0/json-glib/json-path.h
/usr/include/json-glib-1.0/json-glib/json-reader.h
/usr/include/json-glib-1.0/json-glib/json-types.h
/usr/include/json-glib-1.0/json-glib/json-utils.h
/usr/include/json-glib-1.0/json-glib/json-version-macros.h
/usr/include/json-glib-1.0/json-glib/json-version.h