void PaintLayerScrollableArea::ClearPreviousVisualRects() {
  SetHorizontalScrollbarVisualRect(LayoutRect());
  SetVerticalScrollbarVisualRect(LayoutRect());
  SetScrollCornerAndResizerVisualRect(LayoutRect());
}

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.