Reproduce on Chrome via:
1. use a blank profile, or clear mouse content settings
3. Press "Pointer Lock Target1", but do NOT Accept mouse lock
4. Click to Lock the mouse again.
Text on page reads:
document.webkitPointerLockElement locked to target1
Apps track if they have already requested pointer lock and do not send an additional request when one is pending and hasn't received a change or error event.
Related Chrome issue
*** This bug has been marked as a duplicate of bug 91186 ***