Move global function lowestEditableAncestor() to local function in VisibleSelection.cpp

Source/core/editing/EditingUtilities.h

 /*
  * Copyright (C) 2004, 2006, 2008 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 50 matching lines @@
 // -------------------------------------------------------------------------
 
 // Functions returning Node
 
 CORE_EXPORT ContainerNode* highestEditableRoot(const Position&, EditableType = ContentIsEditable);
 ContainerNode* highestEditableRoot(const PositionInComposedTree&, EditableType = ContentIsEditable);
 
 Node* highestEnclosingNodeOfType(const Position&, bool (*nodeIsOfType)(const Node*),
     EditingBoundaryCrossingRule = CannotCrossEditingBoundary, Node* stayWithin = nullptr);
 Node* highestNodeToRemoveInPruning(Node*, Node* excludeNode = nullptr);
-Element* lowestEditableAncestor(Node*);
 
 Element* enclosingBlock(Node*, EditingBoundaryCrossingRule = CannotCrossEditingBoundary);
 Element* enclosingBlock(const Position&, EditingBoundaryCrossingRule);
 Element* enclosingBlockFlowElement(Node&); // Deprecated, use enclosingBlock instead.
 bool inSameContainingBlockFlowElement(Node*, Node*);
 Element* enclosingTableCell(const Position&);
 Element* associatedElementOf(const Position&);
 Node* enclosingEmptyListItem(const VisiblePosition&);
 Element* enclosingAnchorElement(const Position&);
 Element* enclosingElementWithTag(const Position&, const QualifiedName&);
@@ skipping 227 matching lines @@
     // FIXME: this is required until 6853027 is fixed and text checking can do this for us.
     return character == '\'' || character == rightSingleQuotationMarkCharacter || character == hebrewPunctuationGershayimCharacter;
 }
 
 String stringWithRebalancedWhitespace(const String&, bool startIsStartOfParagraph, bool endIsEndOfParagraph);
 const String& nonBreakingSpaceString();
 
 }
 
 #endif