/usr/include/libunity_webapps-0.2/ is in libunity-webapps-dev 2.5.0~+16.04.20160201-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libunity_webapps-0.2/unity-webapps-context.h
/usr/include/libunity_webapps-0.2/unity-webapps-dbus-defs.h
/usr/include/libunity_webapps-0.2/unity-webapps-dbus-util.h
/usr/include/libunity_webapps-0.2/unity-webapps-gen-context.h
/usr/include/libunity_webapps-0.2/unity-webapps-gen-indicator.h
/usr/include/libunity_webapps-0.2/unity-webapps-gen-launcher.h
/usr/include/libunity_webapps-0.2/unity-webapps-gen-music-player.h
/usr/include/libunity_webapps-0.2/unity-webapps-gen-notification.h
/usr/include/libunity_webapps-0.2/unity-webapps-gen-service.h
/usr/include/libunity_webapps-0.2/unity-webapps-indicator-context.h
/usr/include/libunity_webapps-0.2/unity-webapps-launcher-context.h
/usr/include/libunity_webapps-0.2/unity-webapps-music-player-context.h
/usr/include/libunity_webapps-0.2/unity-webapps-notification-context.h
/usr/include/libunity_webapps-0.2/unity-webapps-permissions.h
/usr/include/libunity_webapps-0.2/unity-webapps-rate.h
/usr/include/libunity_webapps-0.2/unity-webapps-sanitizer.h
/usr/include/libunity_webapps-0.2/unity-webapps-service.h