Remove AtomicStringImpl.

Source/core/css/SelectorChecker.h

Index: Source/core/css/SelectorChecker.h
diff --git a/Source/core/css/SelectorChecker.h b/Source/core/css/SelectorChecker.h
index c1f7fd148e9d59bb3e9fb4d6eaa404104c818a10..bab408e90e68f59aa68b5b30108fa2e9ecef2e0e 100644
--- a/Source/core/css/SelectorChecker.h
+++ b/Source/core/css/SelectorChecker.h
@@ -100,7 +100,7 @@ public:
     static bool tagMatches(const Element*, const QualifiedName&);
     static bool isCommonPseudoClassSelector(const CSSSelector*);
     static bool matchesFocusPseudoClass(const Element*);
-    static bool checkExactAttribute(const Element*, const QualifiedName& selectorAttributeName, const AtomicStringImpl* value);
+    static bool checkExactAttribute(const Element*, const QualifiedName& selectorAttributeName, const StringImpl* value);
 
     enum LinkMatchMask { MatchLink = 1, MatchVisited = 2, MatchAll = MatchLink | MatchVisited };
     static unsigned determineLinkMatchType(const CSSSelector*);
@@ -137,7 +137,7 @@ inline bool SelectorChecker::tagMatches(const Element* element, const QualifiedN
     return namespaceURI == starAtom || namespaceURI == element->namespaceURI();
 }
 
-inline bool SelectorChecker::checkExactAttribute(const Element* element, const QualifiedName& selectorAttributeName, const AtomicStringImpl* value)
+inline bool SelectorChecker::checkExactAttribute(const Element* element, const QualifiedName& selectorAttributeName, const StringImpl* value)
 {
     if (!element->hasAttributesWithoutUpdate())
         return false;