inline LayoutUnit borderAndPaddingBeforeInWritingMode(const RenderBox& renderer, WritingMode writingMode)
{
    switch (writingMode) {
    case TopToBottomWritingMode: return renderer.borderTop() + renderer.paddingTop();
    case BottomToTopWritingMode: return renderer.borderBottom() + renderer.paddingBottom();
    case LeftToRightWritingMode: return renderer.borderLeft() + renderer.paddingLeft();
    case RightToLeftWritingMode: return renderer.borderRight() + renderer.paddingRight();
    }

    ASSERT_NOT_REACHED();
    return renderer.borderAndPaddingBefore();
}