/usr/include/ is in khronos-api 0~svn33340-0.1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/khronos-api/
/usr/include/khronos-api/EGL/
/usr/include/khronos-api/EGL/egl.h
/usr/include/khronos-api/EGL/eglext.h
/usr/include/khronos-api/GL/
/usr/include/khronos-api/GL/glcorearb.h
/usr/include/khronos-api/GL/glext.h
/usr/include/khronos-api/GL/glx.h
/usr/include/khronos-api/GL/glxext.h
/usr/include/khronos-api/GL/wgl.h
/usr/include/khronos-api/GL/wglext.h
/usr/include/khronos-api/GLES/
/usr/include/khronos-api/GLES/gl.h
/usr/include/khronos-api/GLES/glext.h
/usr/include/khronos-api/GLES2/
/usr/include/khronos-api/GLES2/gl2.h
/usr/include/khronos-api/GLES2/gl2ext.h
/usr/include/khronos-api/GLES3/
/usr/include/khronos-api/GLES3/gl3.h