/usr/lib/x86_64-linux-gnu/libubuntu-download-manager-client.so.0 is in libubuntu-download-manager-client0 0.3+14.04.20140321-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libubuntu-download-manager-client.so.0.3.0