[New Multicolumn] Add support for column-span:all

Source/core/rendering/RenderBlockFlow.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) 2003-2013 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ skipping 95 matching lines @@
 
     void markAllDescendantsWithFloatsForLayout(RenderBox* floatToRemove = 0, bool inLayout = true);
     void markSiblingsWithFloatsForLayout(RenderBox* floatToRemove = 0);
 
     virtual bool containsFloats() const OVERRIDE FINAL { return m_floatingObjects && !m_floatingObjects->set().isEmpty(); }
     bool containsFloat(RenderBox*) const;
 
     void removeFloatingObjects();
 
     virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0) OVERRIDE;
+    virtual void removeChild(RenderObject* oldChild) OVERRIDE;
 
     void moveAllChildrenIncludingFloatsTo(RenderBlock* toBlock, bool fullRemoveInsert);
 
     bool generatesLineBoxesForInlineChild(RenderObject*);
 
     LayoutUnit logicalTopForFloat(const FloatingObject* floatingObject) const { return isHorizontalWritingMode() ? floatingObject->y() : floatingObject->x(); }
     LayoutUnit logicalBottomForFloat(const FloatingObject* floatingObject) const { return isHorizontalWritingMode() ? floatingObject->maxY() : floatingObject->maxX(); }
     LayoutUnit logicalLeftForFloat(const FloatingObject* floatingObject) const { return isHorizontalWritingMode() ? floatingObject->x() : floatingObject->y(); }
     LayoutUnit logicalRightForFloat(const FloatingObject* floatingObject) const { return isHorizontalWritingMode() ? floatingObject->maxX() : floatingObject->maxY(); }
     LayoutUnit logicalWidthForFloat(const FloatingObject* floatingObject) const { return isHorizontalWritingMode() ? floatingObject->width() : floatingObject->height(); }
@@ skipping 367 matching lines @@
 
 // END METHODS DEFINED IN RenderBlockLineLayout
 
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBlockFlow, isRenderBlockFlow());
 
 } // namespace WebCore
 
 #endif // RenderBlockFlow_h