Introduce composed tree version of inSameLine()

Source/core/editing/VisibleUnits.h

Index: Source/core/editing/VisibleUnits.h
diff --git a/Source/core/editing/VisibleUnits.h b/Source/core/editing/VisibleUnits.h
index 1ecf859ec616b2ee181819d1659d979068be6c88..aeb58123ff7e3a5cbb5316c7eb7f8a0ad4ee56a2 100644
--- a/Source/core/editing/VisibleUnits.h
+++ b/Source/core/editing/VisibleUnits.h
@@ -120,6 +120,7 @@ VisiblePosition endOfLine(const VisiblePosition&);
 CORE_EXPORT VisiblePosition previousLinePosition(const VisiblePosition&, LayoutUnit lineDirectionPoint, EditableType = ContentIsEditable);
 CORE_EXPORT VisiblePosition nextLinePosition(const VisiblePosition&, LayoutUnit lineDirectionPoint, EditableType = ContentIsEditable);
 CORE_EXPORT bool inSameLine(const VisiblePosition&, const VisiblePosition&);
+CORE_EXPORT bool inSameLine(const VisiblePositionInComposedTree&, const VisiblePositionInComposedTree&);
 CORE_EXPORT bool inSameLine(const PositionWithAffinity&, const PositionWithAffinity&);
 CORE_EXPORT bool inSameLine(const PositionInComposedTreeWithAffinity&, const PositionInComposedTreeWithAffinity&);
 bool isStartOfLine(const VisiblePosition&);