/usr/include/ is in libubuntu-application-api-headers 3.0.1+16.04.20160203-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ubuntu/
/usr/include/ubuntu/unit.h
/usr/include/ubuntu/visibility.h
/usr/include/ubuntu/application/
/usr/include/ubuntu/application/instance.h
/usr/include/ubuntu/application/lifecycle_delegate.h
/usr/include/ubuntu/application/id.h
/usr/include/ubuntu/application/location/
/usr/include/ubuntu/application/location/service.h
/usr/include/ubuntu/application/location/heading_update.h
/usr/include/ubuntu/application/location/controller.h
/usr/include/ubuntu/application/location/velocity_update.h
/usr/include/ubuntu/application/location/session.h
/usr/include/ubuntu/application/location/position_update.h
/usr/include/ubuntu/application/options.h
/usr/include/ubuntu/application/archive.h
/usr/include/ubuntu/application/description.h
/usr/include/ubuntu/application/operation_mode.h
/usr/include/ubuntu/application/init.h
/usr/include/ubuntu/application/url_dispatcher/
/usr/include/ubuntu/application/url_dispatcher/service.h
/usr/include/ubuntu/application/url_dispatcher/session.h
/usr/include/ubuntu/application/sensors/
/usr/include/ubuntu/application/sensors/light.h
/usr/include/ubuntu/application/sensors/orientation.h
/usr/include/ubuntu/application/sensors/event/
/usr/include/ubuntu/application/sensors/event/light.h
/usr/include/ubuntu/application/sensors/event/orientation.h
/usr/include/ubuntu/application/sensors/event/proximity.h
/usr/include/ubuntu/application/sensors/event/accelerometer.h
/usr/include/ubuntu/application/sensors/proximity.h
/usr/include/ubuntu/application/sensors/haptic.h
/usr/include/ubuntu/application/sensors/accelerometer.h
/usr/include/ubuntu/status.h