Use Position instead of VisiblePosition for SurroundingText.

Source/core/editing/VisiblePosition.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Portions Copyright (c) 2011 Motorola Mobility, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 707 matching lines @@
     m_deepPosition.showTreeForThis();
 }
 
 #endif
 
 PassRefPtrWillBeRawPtr<Range> makeRange(const VisiblePosition &start, const VisiblePosition &end)
 {
     if (start.isNull() || end.isNull())
         return nullptr;
 
-    Position s = start.deepEquivalent().parentAnchoredEquivalent();
-    Position e = end.deepEquivalent().parentAnchoredEquivalent();
-    if (s.isNull() || e.isNull())
-        return nullptr;
-
-    return Range::create(s.containerNode()->document(), s.containerNode(), s.offsetInContainerNode(), e.containerNode(), e.offsetInContainerNode());
+    return makeRange(start.deepEquivalent(), end.deepEquivalent());
 }
 
 VisiblePosition startVisiblePosition(const Range *r, EAffinity affinity)
 {
     return VisiblePosition(r->startPosition(), affinity);
 }
 
 bool setStart(Range *r, const VisiblePosition &visiblePosition)
 {
     if (!r)
@@ skipping 60 matching lines @@
     if (vpos)
         vpos->showTreeForThis();
 }
 
 void showTree(const WebCore::VisiblePosition& vpos)
 {
     vpos.showTreeForThis();
 }
 
 #endif