Introduce composed tree version of endOfDocument()

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 51b060c8ae00bddf007417ac6672149cd29b94c0..93ff96ac721e24380b596c5dd9f9e3a5e3c85e1e 100644
--- a/Source/core/editing/VisibleUnits.h
+++ b/Source/core/editing/VisibleUnits.h
@@ -158,9 +158,9 @@ bool isEndOfBlock(const VisiblePosition&);
 
 // document
 VisiblePosition startOfDocument(const Node*);
-VisiblePosition endOfDocument(const Node*);
 VisiblePosition startOfDocument(const VisiblePosition&);
-VisiblePosition endOfDocument(const VisiblePosition&);
+CORE_EXPORT VisiblePosition endOfDocument(const VisiblePosition&);
+CORE_EXPORT VisiblePositionInComposedTree endOfDocument(const VisiblePositionInComposedTree&);
 bool isStartOfDocument(const VisiblePosition&);
 bool isEndOfDocument(const VisiblePosition&);