Remove column set range map from RenderFlowThread.

Source/core/rendering/RenderFlexibleBox.cpp

Index: Source/core/rendering/RenderFlexibleBox.cpp
diff --git a/Source/core/rendering/RenderFlexibleBox.cpp b/Source/core/rendering/RenderFlexibleBox.cpp
index d71accfa31a8cca3c227a327e50373efdec09540..a2220935f50b6250f53fdc43fa80b77a09818ac6 100644
--- a/Source/core/rendering/RenderFlexibleBox.cpp
+++ b/Source/core/rendering/RenderFlexibleBox.cpp
@@ -256,8 +256,6 @@ void RenderFlexibleBox::layoutBlock(bool relayoutChildren)
 
         layoutPositionedObjects(relayoutChildren || isDocumentElement());
 
-        computeRegionRangeForBlock(flowThreadContainingBlock());
-
         // FIXME: css3/flexbox/repaint-rtl-column.html seems to issue paint invalidations for more overflow than it needs to.
         computeOverflow(clientLogicalBottomAfterRepositioning());
     }