Select Menu List Wrongly Positioned

95776: REGRESSION(r120832): Layer::clampScrollOffset doesn't properly clamp

Manual test: click on the menu below and <select> the 'shown' option. Click somewhere on the page so that the <select> loses focus and click again on the <select>.

To pass the menu should be properly placed below the <select>.

| Test select: | hiddenshown | | Lorem ipsum | dolor sic amet. |