/usr/lib/x86_64-linux-gnu/libboost_chrono.so is in libboost-chrono1.58-dev 1.58.0+dfsg-5ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libboost_chrono.so.1.58.0
/usr/lib/x86_64-linux-gnu/libboost_chrono.so.1.58.0