Get rid of TreeBoundaryCrossingRules.

Source/core/css/resolver/StyleResolver.h

Index: Source/core/css/resolver/StyleResolver.h
diff --git a/Source/core/css/resolver/StyleResolver.h b/Source/core/css/resolver/StyleResolver.h
index 64646bbad90d026979aac09cf3447419ae9faf96..cd1c5b936bde0b60ad35d4a0caf062c2c954a775 100644
--- a/Source/core/css/resolver/StyleResolver.h
+++ b/Source/core/css/resolver/StyleResolver.h
@@ -29,7 +29,6 @@
 #include "core/css/RuleSet.h"
 #include "core/css/SelectorChecker.h"
 #include "core/css/SelectorFilter.h"
-#include "core/css/TreeBoundaryCrossingRules.h"
 #include "core/css/resolver/CSSPropertyPriority.h"
 #include "core/css/resolver/MatchedPropertiesCache.h"
 #include "core/css/resolver/StyleBuilder.h"
@@ -189,8 +188,6 @@ public:
 
     DECLARE_TRACE();
 
-    void addTreeBoundaryCrossingScope(ContainerNode& scope);
-
 private:
     PassRefPtr<ComputedStyle> initialStyleForElement();
 
@@ -267,7 +264,6 @@ private:
     OwnPtrWillBeMember<RuleSet> m_siblingRuleSet;
     OwnPtrWillBeMember<RuleSet> m_uncommonAttributeRuleSet;
     OwnPtrWillBeMember<RuleSet> m_watchedSelectorsRules;
-    TreeBoundaryCrossingRules m_treeBoundaryCrossingRules;
 
     bool m_needCollectFeatures;
     bool m_printMediaType;