Refactor avoidsFloats() to reflect CSS2.1 spec more clearly

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 166 matching lines @@
 
     // FIXME: This should be const to avoid a const_cast, but can modify child dirty bits and RenderCombineText
     void computeInlinePreferredLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth);
 
     GapRects inlineSelectionGaps(const RenderBlock* rootBlock, const LayoutPoint& rootBlockPhysicalPosition, const LayoutSize& offsetFromRootBlock,
         LayoutUnit& lastLogicalTop, LayoutUnit& lastLogicalLeft, LayoutUnit& lastLogicalRight, const PaintInfo*) const;
 
     LayoutUnit paginationStrut() const { return m_rareData ? m_rareData->m_paginationStrut : LayoutUnit(); }
     void setPaginationStrut(LayoutUnit);
 
-    virtual bool avoidsFloats() const override;
-
     LayoutUnit xPositionForFloatIncludingMargin(const FloatingObject* child) const
     {
         if (isHorizontalWritingMode())
             return child->x() + child->renderer()->marginLeft();
 
         return child->x() + marginBeforeForChild(child->renderer());
     }
 
     LayoutUnit yPositionForFloatIncludingMargin(const FloatingObject* child) const
     {
@@ skipping 301 matching lines @@
 
 // END METHODS DEFINED IN RenderBlockLineLayout
 
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBlockFlow, isRenderBlockFlow());
 
 } // namespace blink
 
 #endif // RenderBlockFlow_h