Have StyledMarkupSerializer work on the Composed tree

Source/core/editing/VisibleSelection.cpp

Index: Source/core/editing/VisibleSelection.cpp
diff --git a/Source/core/editing/VisibleSelection.cpp b/Source/core/editing/VisibleSelection.cpp
index 1026a939b56a50609928566ddc1bfea3f32a5692..4c1213c29cd864bba70351c9e043c71ea2726079 100644
--- a/Source/core/editing/VisibleSelection.cpp
+++ b/Source/core/editing/VisibleSelection.cpp
@@ -232,6 +232,11 @@ void VisibleSelection::normalizePositions(const Position& start, const Position&
     return normalizePositionsAlgorithm<Position>(start, end, outStart, outEnd);
 }
 
+void VisibleSelection::normalizePositions(const PositionInComposedTree& start, const PositionInComposedTree& end, PositionInComposedTree* outStart, PositionInComposedTree* outEnd)
+{
+    return normalizePositionsAlgorithm<PositionInComposedTree>(start, end, outStart, outEnd);
+}
+
 bool VisibleSelection::toNormalizedPositions(Position& start, Position& end) const
 {
     if (isNone())