Remove some dead code from rendering/ folder

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 36 matching lines @@
 class LineBreaker;
 class LineWidth;
 class RenderMultiColumnFlowThread;
 
 class RenderBlockFlow : public RenderBlock {
 public:
     explicit RenderBlockFlow(ContainerNode*);
     virtual ~RenderBlockFlow();
 
     static RenderBlockFlow* createAnonymous(Document*);
-    RenderBlockFlow* createAnonymousBlockFlow() const;
 
     virtual bool isRenderBlockFlow() const OVERRIDE FINAL { return true; }
 
     virtual void layoutBlock(bool relayoutChildren) OVERRIDE;
 
     virtual void computeOverflow(LayoutUnit oldClientAfterEdge, bool recomputeFloats = false) OVERRIDE;
     virtual void deleteLineBoxTree() OVERRIDE FINAL;
 
     LayoutUnit availableLogicalWidthForLine(LayoutUnit position, bool shouldIndentText, LayoutUnit logicalHeight = 0) const
     {
@@ skipping 426 matching lines @@
 
 // END METHODS DEFINED IN RenderBlockLineLayout
 
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBlockFlow, isRenderBlockFlow());
 
 } // namespace WebCore
 
 #endif // RenderBlockFlow_h