Make enclosingBlockFlowElement() to take const Node reference

third_party/WebKit/Source/core/editing/EditingUtilities.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 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 700 matching lines @@
 Element* enclosingBlock(const Position& position, EditingBoundaryCrossingRule rule)
 {
     return enclosingBlockAlgorithm<EditingStrategy>(position, rule);
 }
 
 Element* enclosingBlock(const PositionInFlatTree& position, EditingBoundaryCrossingRule rule)
 {
     return enclosingBlockAlgorithm<EditingInFlatTreeStrategy>(position, rule);
 }
 
-Element* enclosingBlockFlowElement(Node& node)
+Element* enclosingBlockFlowElement(const Node& node)
 {
     if (isBlockFlowElement(node))
-        return &toElement(node);
+        return const_cast<Element*>(&toElement(node));
 
     for (Node* n = node.parentNode(); n; n = n->parentNode()) {
         if (isBlockFlowElement(*n) || isHTMLBodyElement(*n))
             return toElement(n);
     }
-    return 0;
+    return nullptr;
 }
 
 bool inSameContainingBlockFlowElement(Node* a, Node* b)
 {
     return a && b && enclosingBlockFlowElement(*a) == enclosingBlockFlowElement(*b);
 }
 
 bool nodeIsUserSelectAll(const Node* node)
 {
     return RuntimeEnabledFeatures::userSelectAllEnabled() && node && node->layoutObject() && node->layoutObject()->style()->userSelect() == SELECT_ALL;
@@ skipping 936 matching lines @@
     // instead of possibly at the end of the last node before the selection
     return mostForwardCaretPosition(visiblePosition.deepEquivalent());
 }
 
 bool isTextSecurityNode(const Node* node)
 {
     return node && node->layoutObject() && node->layoutObject()->style()->textSecurity() != TSNONE;
 }
 
 } // namespace blink