Handle ::content and :host-context correctly in SelectorQuery.

Source/core/css/CSSSelectorList.h

 /*
  * Copyright (C) 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 43 matching lines @@
     {
         const CSSSelector& current = selectorAt(index);
         const CSSSelector* next = this->next(current);
         if (!next)
             return kNotFound;
         return next - m_selectorArray;
     }
 
     bool selectorsNeedNamespaceResolution();
 
+    bool selectorNeedsUpdatedDistribution(size_t index) const;
+
+    // TODO(esprehn): These methods are confusing and incorrectly named.
     bool hasShadowDistributedAt(size_t index) const;
     bool selectorCrossesTreeScopes(size_t index) const;
 
     String selectorsText() const;
 
 private:
     unsigned length() const;
     void deleteSelectors();
 
     // Hide.
     CSSSelectorList& operator=(const CSSSelectorList&);
 
     // End of a multipart selector is indicated by m_isLastInTagHistory bit in the last item.
     // End of the array is indicated by m_isLastInSelectorList bit in the last item.
     CSSSelector* m_selectorArray;
 };
 
 inline const CSSSelector* CSSSelectorList::next(const CSSSelector& current)
 {
     // Skip subparts of compound selectors.
     const CSSSelector* last = &current;
     while (!last->isLastInTagHistory())
         last++;
     return last->isLastInSelectorList() ? 0 : last + 1;
 }
 
 } // namespace blink
 
 #endif // CSSSelectorList_h