LayoutObject::paintInvalidationParent() to fix multicol spanner invalidation

third_party/WebKit/Source/core/layout/LayoutObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1649 matching lines @@
     void checkBlockPositionedObjectsNeedLayout();
 #endif
 
     bool isTextOrSVGChild() const { return isText() || (isSVG() && !isSVGRoot()); }
 
     static bool isAllowedToModifyLayoutTreeStructure(Document&);
 
     // The passed rect is mutated into the coordinate space of the paint invalidation container.
     const LayoutBoxModelObject* invalidatePaintRectangleInternal(const LayoutRect&) const;
 
-    LayoutObject* parentCrossingFrameBoundaries() const;
+    // Returns the parent for paint invalidation.
+    // - For LayoutView, returns the owner layout object in the containing frame if any or nullptr;
+    // - For multi-column spanner, returns the spanner placeholder;
+    // - Otherwise returns parent().
+    LayoutObject* paintInvalidationParent() const;
 
     static LayoutPoint uninitializedPaintOffset() { return LayoutPoint(LayoutUnit::max(), LayoutUnit::max()); }
 
     RefPtr<ComputedStyle> m_style;
 
     // Oilpan: This untraced pointer to the owning Node is considered safe.
     UntracedMember<Node> m_node;
 
     LayoutObject* m_parent;
     LayoutObject* m_previous;
@@ skipping 507 matching lines @@
 void showTree(const blink::LayoutObject*);
 void showLineTree(const blink::LayoutObject*);
 void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 void showLayoutTree(const blink::LayoutObject* object1, const blink::LayoutObject* object2);
 
 #endif
 
 #endif // LayoutObject_h