/usr/share/doc/libwebrtc-audio-processing-dev/changelog.Debian.gz is in libwebrtc-audio-processing-dev 0.3-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libwebrtc-audio-processing-dev/../libwebrtc-audio-processing1/changelog.Debian.gz