/usr/share/doc/libwnck-dev/html is in libwnck-doc 2.30.7-5.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libwnck-dev/../../gtk-doc/html/libwnck
/usr/share/doc/libwnck-dev/../../gtk-doc/html/libwnck