message: Fix unhandled exception on iOS when exitPointerLock is called.
diff: @@ -2003,7 +2003,7 @@ class ViewLookAndMove extends ViewNavigate {
  document.removeEventListener("pointerlockchange", this._pointerLockChangeListener, false);
  this._pointerLockChangeListener = undefined;
  }
  - if (null !== document.pointerLockElement)
  + if (null !== document.pointerLockElement && undefined !== document.exitPointerLock)
  document.exitPointerLock();
  }
  