Strip anonymous wrappers when a block flow no longer requires them

Source/core/layout/LayoutBlock.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 210 matching lines @@
     bool recalcOverflowAfterStyleChange();
 
 protected:
     void willBeDestroyed() override;
 
     void dirtyForLayoutFromPercentageHeightDescendants(SubtreeLayoutScope&);
 
     void layout() override;
     bool updateImageLoadingPriorities() final;
 
+    enum AdjacentSiblings {
+        PreviousSiblings,
+        NextSiblings
+    };
+
     enum PositionedLayoutBehavior {
         DefaultLayout,
         LayoutOnlyFixedPositionedObjects,
         ForcedLayoutAfterContainingBlockMoved
     };
 
     void layoutPositionedObjects(bool relayoutChildren, PositionedLayoutBehavior = DefaultLayout);
     void markFixedPositionObjectForLayoutIfNeeded(LayoutObject* child, SubtreeLayoutScope&);
 
     LayoutUnit marginIntrinsicLogicalWidthForChild(LayoutBox& child) const;
@@ skipping 70 matching lines @@
     // Promote all children and make them siblings that come right after this block.
     void promoteAllChildrenAndInsertAfter();
 
     virtual void removeLeftoverAnonymousBlock(LayoutBlock* child);
 
     static void collapseAnonymousBlockChild(LayoutBlock* parent, LayoutBlock* child);
 
     void dirtyLinesFromChangedChild(LayoutObject* child) final { m_lineBoxes.dirtyLinesFromChangedChild(LineLayoutItem(this), LineLayoutItem(child)); }
 
     void addChildIgnoringContinuation(LayoutObject* newChild, LayoutObject* beforeChild) override;
+    void addAdjacentSiblingsToAnonymousBox(AdjacentSiblings, LayoutBlock* anonymousBox);
 
     bool isSelfCollapsingBlock() const override;
 
     void removeAnonymousWrappersIfRequired();
 
     void insertIntoTrackedLayoutBoxMaps(LayoutBox* descendant, TrackedDescendantsMap*&, TrackedContainerMap*&);
     static void removeFromTrackedLayoutBoxMaps(LayoutBox* descendant, TrackedDescendantsMap*&, TrackedContainerMap*&);
 
     Node* nodeForHitTest() const;
 
@@ skipping 97 matching lines @@
     // FIXME: This is temporary as we move code that accesses block flow
     // member variables out of LayoutBlock and into LayoutBlockFlow.
     friend class LayoutBlockFlow;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlock, isLayoutBlock());
 
 } // namespace blink
 
 #endif // LayoutBlock_h