Make SelectorChecker a const operation over element.

sky/engine/core/dom/SelectorQuery.cpp

 /*
  * Copyright (C) 2011, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Samsung Electronics. 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.
@@ skipping 55 matching lines @@
 {
     for (Element* element = ElementTraversal::firstWithin(rootNode); element; element = ElementTraversal::next(*element, &rootNode)) {
         if (selectorMatches(rootNode, *element))
             return element;
     }
     return nullptr;
 }
 
 bool SelectorQuery::selectorMatches(ContainerNode& rootNode, Element& element) const
 {
-    SelectorChecker checker(element.document(), SelectorChecker::QueryingRules);
+    SelectorChecker checker;
     for (const CSSSelector* selector = m_selectors.first(); selector; selector = CSSSelectorList::next(*selector)) {
         SelectorChecker::SelectorCheckingContext context(*selector, &element);
         context.scope = !rootNode.isDocumentNode() ? &rootNode : 0;
         if (checker.match(context))
             return true;
     }
     return false;
 }
 
 SelectorQuery* SelectorQueryCache::add(const AtomicString& selectors, const Document& document, ExceptionState& exceptionState)
@@ skipping 12 matching lines @@
     }
 
     const unsigned maximumSelectorQueryCacheSize = 256;
     if (m_entries.size() == maximumSelectorQueryCacheSize)
         m_entries.remove(m_entries.begin());
 
     return m_entries.add(selectors, SelectorQuery::adopt(selectorList)).storedValue->value.get();
 }
 
 }