Drop const_iterator for AttributeCollection

Source/core/dom/ElementData.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 96 matching lines @@
 bool ElementData::isEquivalent(const ElementData* other) const
 {
     AttributeCollection attributes = this->attributes();
     if (!other)
         return attributes.isEmpty();
 
     AttributeCollection otherAttributes = other->attributes();
     if (attributes.size() != otherAttributes.size())
         return false;
 
-    AttributeCollection::const_iterator end = attributes.end();
-    for (AttributeCollection::const_iterator it = attributes.begin(); it != end; ++it) {
+    AttributeCollection::iterator end = attributes.end();
+    for (AttributeCollection::iterator it = attributes.begin(); it != end; ++it) {
         const Attribute* otherAttr = otherAttributes.find(it->name());
         if (!otherAttr || it->value() != otherAttr->value())
             return false;
     }
     return true;
 }
 
 void ElementData::trace(Visitor* visitor)
 {
     if (m_isUnique)
@@ skipping 83 matching lines @@
     return adoptRefWillBeNoop(new (slot) ShareableElementData(*this));
 }
 
 void UniqueElementData::traceAfterDispatch(Visitor* visitor)
 {
     visitor->trace(m_presentationAttributeStyle);
     ElementData::traceAfterDispatch(visitor);
 }
 
 } // namespace blink