static PassRefPtr<TransformPaintPropertyNode> createScrollTranslationIfNeeded(const LayoutObject& object, PaintPropertyTreeBuilderContext& context)
{
    if (!object.isBoxModelObject() || !object.hasOverflowClip())
        return nullptr;

    PaintLayer* layer = toLayoutBoxModelObject(object).layer();
    ASSERT(layer);
    DoubleSize scrollOffset = layer->scrollableArea()->scrollOffset();
    if (scrollOffset.isZero() && !layer->scrollsOverflow())
        return nullptr;

    RefPtr<TransformPaintPropertyNode> newTransformNodeForScrollTranslation = TransformPaintPropertyNode::create(
        TransformationMatrix().translate(-scrollOffset.width(), -scrollOffset.height()),
        FloatPoint3D(), context.currentTransform);
    context.currentTransform = newTransformNodeForScrollTranslation.get();
    return newTransformNodeForScrollTranslation.release();
}
void PaintPropertyTreeBuilder::updateScrollTranslation(const LayoutObject& object, PaintPropertyTreeBuilderContext& context)
{
    if (!object.isBoxModelObject() || !object.hasOverflowClip())
        return;

    PaintLayer* layer = toLayoutBoxModelObject(object).layer();
    ASSERT(layer);
    DoubleSize scrollOffset = layer->getScrollableArea()->scrollOffset();
    if (scrollOffset.isZero() && !layer->scrollsOverflow())
        return;

    RefPtr<TransformPaintPropertyNode> scrollTranslation = TransformPaintPropertyNode::create(
        TransformationMatrix().translate(-scrollOffset.width(), -scrollOffset.height()),
        FloatPoint3D(),
        context.currentTransform);
    context.currentTransform = scrollTranslation.get();
    object.getMutableForPainting().ensureObjectPaintProperties().setScrollTranslation(scrollTranslation.release());
}