/usr/share/gtk-doc/html/ is in libxfcegui4-dev 4.8.1-5.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gtk-doc/html/libxfcegui4/
/usr/share/gtk-doc/html/libxfcegui4/XfceAboutDialog.html
/usr/share/gtk-doc/html/libxfcegui4/XfceAppMenuItem.html
/usr/share/gtk-doc/html/libxfcegui4/XfceFramebox.html
/usr/share/gtk-doc/html/libxfcegui4/XfceHeading.html
/usr/share/gtk-doc/html/libxfcegui4/XfceIconTheme.html
/usr/share/gtk-doc/html/libxfcegui4/XfceTitledDialog.html
/usr/share/gtk-doc/html/libxfcegui4/home.png
/usr/share/gtk-doc/html/libxfcegui4/index.html
/usr/share/gtk-doc/html/libxfcegui4/index.sgml
/usr/share/gtk-doc/html/libxfcegui4/left.png
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-Standard-Macros.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-Xfce-Gdk-extensions.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-Xfce-Gtk+-extensions.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-XfceFileChooser.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-core.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-dialogs.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-fundamentals.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-netk.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4-xfce-exec.html
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4.devhelp
/usr/share/gtk-doc/html/libxfcegui4/libxfcegui4.devhelp2
/usr/share/gtk-doc/html/libxfcegui4/reference.html
/usr/share/gtk-doc/html/libxfcegui4/right.png
/usr/share/gtk-doc/html/libxfcegui4/style.css
/usr/share/gtk-doc/html/libxfcegui4/up.png