/usr/share/gtk-doc/html/gstreamer-libs-0.10 is in gstreamer0.10-doc 0.10.36-1.2ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/gtk-doc/html/../../doc/gstreamer0.10-doc/gstreamer-libs-0.10