Remove some dead code from rendering/ folder

Source/core/rendering/RenderBlockFlow.cpp

 /*
  * 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
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 152 matching lines @@
 {
 }
 
 RenderBlockFlow* RenderBlockFlow::createAnonymous(Document* document)
 {
     RenderBlockFlow* renderer = new RenderBlockFlow(0);
     renderer->setDocumentForAnonymous(document);
     return renderer;
 }
 
-RenderBlockFlow* RenderBlockFlow::createAnonymousBlockFlow() const
-{
-    return toRenderBlockFlow(createAnonymousWithParentRendererAndDisplay(this, BLOCK));
-}
-
 RenderObject* RenderBlockFlow::layoutSpecialExcludedChild(bool relayoutChildren, SubtreeLayoutScope& layoutScope)
 {
     RenderMultiColumnFlowThread* flowThread = multiColumnFlowThread();
     if (!flowThread)
         return 0;
     setLogicalTopForChild(flowThread, borderBefore() + paddingBefore());
     flowThread->layoutColumns(relayoutChildren, layoutScope);
     determineLogicalLeftPositionForChild(flowThread);
     return flowThread;
 }
@@ skipping 2616 matching lines @@
 RenderBlockFlow::RenderBlockFlowRareData& RenderBlockFlow::ensureRareData()
 {
     if (m_rareData)
         return *m_rareData;
 
     m_rareData = adoptPtr(new RenderBlockFlowRareData(this));
     return *m_rareData;
 }
 
 } // namespace WebCore