Remove multicol special-cases from invalidation and the pre-paint tree walk

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
@@ skipping 2049 matching lines @@
   void removeCursorImageClient(const CursorList*);
 
 #if DCHECK_IS_ON()
   void checkBlockPositionedObjectsNeedLayout();
 #endif
 
   bool isTextOrSVGChild() const { return isText() || isSVGChild(); }
 
   static bool isAllowedToModifyLayoutTreeStructure(Document&);
 
-  // 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().
+  // Returns the parent for paint invalidation. For LayoutView, returns the
+  // owner layout object in the containing frame if any, or nullptr.
   inline LayoutObject* paintInvalidationParent() const;
   LayoutObject* slowPaintInvalidationParentForTesting() const;
 
   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 594 matching lines @@
 CORE_EXPORT void showLineTree(const blink::LayoutObject*);
 CORE_EXPORT void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 CORE_EXPORT void showLayoutTree(const blink::LayoutObject* object1,
                                 const blink::LayoutObject* object2);
 
 #endif
 
 #endif  // LayoutObject_h