Replace RenderArena with PartitionAlloc.

Source/core/rendering/RenderMultiColumnSet.cpp

 /*
  * Copyright (C) 2012 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 33 matching lines @@
     , m_minimumColumnHeight(0)
     , m_forcedBreaksCount(0)
     , m_maximumDistanceBetweenForcedBreaks(0)
     , m_forcedBreakOffset(0)
 {
 }
 
 RenderMultiColumnSet* RenderMultiColumnSet::createAnonymous(RenderFlowThread* flowThread)
 {
     Document* document = flowThread->document();
-    RenderMultiColumnSet* renderer = new (document->renderArena()) RenderMultiColumnSet(flowThread);
+    RenderMultiColumnSet* renderer = new RenderMultiColumnSet(flowThread);
     renderer->setDocumentForAnonymous(document);
     return renderer;
 }
 
 LayoutUnit RenderMultiColumnSet::pageLogicalTopForOffset(LayoutUnit offset) const
 {
     LayoutUnit portionLogicalTop = (isHorizontalWritingMode() ? flowThreadPortionRect().y() : flowThreadPortionRect().x());
     unsigned columnIndex = (offset - portionLogicalTop) / computedColumnHeight();
     return portionLogicalTop + columnIndex * computedColumnHeight();
 }
@@ skipping 347 matching lines @@
         fragments.append(fragment);
     }
 }
 
 const char* RenderMultiColumnSet::renderName() const
 {    
     return "RenderMultiColumnSet";
 }
 
 }