/usr/ is in libmatemixer-dev 1.16.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/mate-mixer/
/usr/include/mate-mixer/libmatemixer/
/usr/include/mate-mixer/libmatemixer/matemixer-app-info.h
/usr/include/mate-mixer/libmatemixer/matemixer-context.h
/usr/include/mate-mixer/libmatemixer/matemixer-device-switch.h
/usr/include/mate-mixer/libmatemixer/matemixer-device.h
/usr/include/mate-mixer/libmatemixer/matemixer-enum-types.h
/usr/include/mate-mixer/libmatemixer/matemixer-enums.h
/usr/include/mate-mixer/libmatemixer/matemixer-stored-control.h
/usr/include/mate-mixer/libmatemixer/matemixer-stream-control.h
/usr/include/mate-mixer/libmatemixer/matemixer-stream-switch.h
/usr/include/mate-mixer/libmatemixer/matemixer-stream-toggle.h
/usr/include/mate-mixer/libmatemixer/matemixer-stream.h
/usr/include/mate-mixer/libmatemixer/matemixer-switch-option.h
/usr/include/mate-mixer/libmatemixer/matemixer-switch.h
/usr/include/mate-mixer/libmatemixer/matemixer-types.h
/usr/include/mate-mixer/libmatemixer/matemixer-version.h
/usr/include/mate-mixer/libmatemixer/matemixer.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/libmatemixer.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libmatemixer-dev/
/usr/share/doc/libmatemixer-dev/changelog.Debian.gz
/usr/share/doc/libmatemixer-dev/changelog.gz
/usr/share/doc/libmatemixer-dev/copyright
/usr/lib/x86_64-linux-gnu/libmatemixer.so