/usr/share/doc/icedtea-8-plugin/changelog.Debian.gz is in icedtea-8-plugin 1.6.2-3.1ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/icedtea-8-plugin/../icedtea-netx/changelog.Debian.gz