/usr/include/openni2/ is in libopenni2-dev 2.2.0.33+dfsg-7+deb9u1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/openni2/Android-Arm/
/usr/include/openni2/Android-Arm/OniPlatformAndroid-Arm.h
/usr/include/openni2/Driver/
/usr/include/openni2/Driver/OniDriverAPI.h
/usr/include/openni2/Driver/OniDriverTypes.h
/usr/include/openni2/Linux-Arm/
/usr/include/openni2/Linux-Arm/OniPlatformLinux-Arm.h
/usr/include/openni2/Linux-generic/
/usr/include/openni2/Linux-generic/OniPlatformLinux-generic.h
/usr/include/openni2/Linux-x86/
/usr/include/openni2/Linux-x86/OniPlatformLinux-x86.h
/usr/include/openni2/MacOSX/
/usr/include/openni2/MacOSX/OniPlatformMacOSX.h
/usr/include/openni2/OniCAPI.h
/usr/include/openni2/OniCEnums.h
/usr/include/openni2/OniCProperties.h
/usr/include/openni2/OniCTypes.h
/usr/include/openni2/OniEnums.h
/usr/include/openni2/OniPlatform.h
/usr/include/openni2/OniProperties.h
/usr/include/openni2/OniVersion.h
/usr/include/openni2/OpenNI.h
/usr/include/openni2/PS1080.h
/usr/include/openni2/PSLink.h
/usr/include/openni2/PrimeSense.h
/usr/include/openni2/Win32/
/usr/include/openni2/Win32/OniPlatformWin32.h