The plan is for WebXR to initially implement a simplified input system that is focus on point-and-click style interactions rather than exposing full input device state. The exact shape of the API is still under discussion (see https://github.com/immersive-web/webxr/issues/319 for the latest). The eventual API should be implemented once the details are firmed up.
Comment 1 by bugdroid1@chromium.org
, Mar 6 2018