repositionOverlay() {
      const ctrl = /** @type {OverlayController} */ (this._overlayCtrl);
      if (ctrl.placementMode === 'local' && ctrl._popper) {
        ctrl._popper.update();
      }
    }
Sometimes it's needed to recompute Popper position of an overlay, for instance when we have
an opened combobox and the surrounding context changes (the space consumed by the textbox
increases vertically)