Get rid of a redundant function Position::deprecatedEditingOffset()

Source/core/editing/Position.h

Index: Source/core/editing/Position.h
diff --git a/Source/core/editing/Position.h b/Source/core/editing/Position.h
index 496e35502d612574739363db7b17ee3503092e6b..308c5d631537adcebe0a8fed3b452c67a33a12d0 100644
--- a/Source/core/editing/Position.h
+++ b/Source/core/editing/Position.h
@@ -137,9 +137,6 @@ public:
     // anchor node.
     int computeEditingOffset() const;
 
-    // New code should not use this function.
-    int deprecatedEditingOffset() const;
-
     // These are convenience methods which are smart about whether the position is neighbor anchored or parent anchored
     Node* computeNodeBeforePosition() const;
     Node* computeNodeAfterPosition() const;