/usr/share/doc/libwebkit2-sharp-4.0-cil-dev/changelog.Debian.gz is in libwebkit2-sharp-4.0-cil-dev 2.10.9+git20160917-1.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libwebkit2-sharp-4.0-cil-dev/../libwebkit2-sharp-4.0-cil/changelog.Debian.gz