Introduce positionForPoint() in LocalFrame class as replacement of visiblePositionForPoint()

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 c0181c12bd7402842a092f053a0dc055849a9406..710f24a737413b32a0715978a2a93d4106e0fbff 100644
--- a/Source/core/editing/VisibleSelection.cpp
+++ b/Source/core/editing/VisibleSelection.cpp
@@ -70,6 +70,11 @@ VisibleSelection::VisibleSelection(const PositionInComposedTree& base, const Pos
 {
 }
 
+VisibleSelection::VisibleSelection(const PositionWithAffinity& pos, bool isDirectional)
+    : VisibleSelection(pos.position(), pos.affinity(), isDirectional)
+{
+}
+
 VisibleSelection::VisibleSelection(const VisiblePosition& pos, bool isDirectional)
     : VisibleSelection(pos, pos, isDirectional)
 {