Remove column set range map from RenderFlowThread.

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 470 matching lines @@
             }
         }
     }
 
     bool heightChanged = (previousHeight != newHeight);
     if (heightChanged)
         relayoutChildren = true;
 
     layoutPositionedObjects(relayoutChildren || isDocumentElement(), oldLeft != logicalLeft() ? ForcedLayoutAfterContainingBlockMoved : DefaultLayout);
 
-    computeRegionRangeForBlock(flowThreadContainingBlock());
-
     // Add overflow from children (unless we're multi-column, since in that case all our child overflow is clipped anyway).
     computeOverflow(oldClientAfterEdge);
 
     m_descendantsWithFloatsMarkedForLayout = false;
     return true;
 }
 
 void RenderBlockFlow::determineLogicalLeftPositionForChild(RenderBox* child)
 {
     LayoutUnit startPosition = borderStart() + paddingStart();
@@ skipping 2408 matching lines @@
 RenderBlockFlow::RenderBlockFlowRareData& RenderBlockFlow::ensureRareData()
 {
     if (m_rareData)
         return *m_rareData;
 
     m_rareData = adoptPtrWillBeNoop(new RenderBlockFlowRareData(this));
     return *m_rareData;
 }
 
 } // namespace blink