Include overflow when setting the logical flowthread bottom on the last column set.

Source/core/layout/LayoutMultiColumnSet.h

Index: Source/core/layout/LayoutMultiColumnSet.h
diff --git a/Source/core/layout/LayoutMultiColumnSet.h b/Source/core/layout/LayoutMultiColumnSet.h
index a563ece690d6e5a5a289d8eded33ac35066c23f0..0eecd1453b7e025f7eb2b5df004f49f61c491b0b 100644
--- a/Source/core/layout/LayoutMultiColumnSet.h
+++ b/Source/core/layout/LayoutMultiColumnSet.h
@@ -137,10 +137,6 @@ public:
     // set or spanner.
     void endFlow(LayoutUnit offsetInFlowThread);
 
-    // Expand this set's flow thread portion rectangle to contain all trailing flow thread
-    // overflow. Only to be called on the last set.
-    void expandToEncompassFlowThreadContentsIfNeeded();
-
     void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const final;
 
     void attachToFlowThread();