Disable paint invalidation state assert in invalidateScrollCornerRect()

Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp

Index: Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
diff --git a/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp b/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
index d60881bca20e76efa59897efde23d827a611e561..a8fc6806cfa9d788197770e98dce21c519c3fdff 100644
--- a/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
+++ b/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
@@ -251,6 +251,8 @@ void DeprecatedPaintLayerScrollableArea::invalidateScrollCornerRect(const IntRec
     ASSERT(!layerForScrollCorner());
 
     if (m_scrollCorner) {
+        // FIXME: We should not allow paint invalidation out of paint invalidation state. crbug.com/457415
+        DisablePaintInvalidationStateAsserts disabler;
         m_scrollCorner->invalidatePaintRectangle(LayoutRect(rect));
         if (RuntimeEnabledFeatures::slimmingPaintEnabled())
             box().invalidateDisplayItemClientForNonCompositingDescendantsOf(*m_scrollCorner);