Remove support for pseudo classes in <content select>.

Source/core/dom/SelectorQuery.cpp

Index: Source/core/dom/SelectorQuery.cpp
diff --git a/Source/core/dom/SelectorQuery.cpp b/Source/core/dom/SelectorQuery.cpp
index 6a5d428934d4258c09430f6dfa83f20f63bad1f4..af3bc282f14323a4425cf408e34e1404176059e0 100644
--- a/Source/core/dom/SelectorQuery.cpp
+++ b/Source/core/dom/SelectorQuery.cpp
@@ -29,7 +29,6 @@
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/css/SelectorChecker.h"
-#include "core/css/SiblingTraversalStrategies.h"
 #include "core/css/parser/CSSParser.h"
 #include "core/dom/Document.h"
 #include "core/dom/ElementTraversal.h"
@@ -123,7 +122,7 @@ inline bool SelectorDataList::selectorMatches(const CSSSelector& selector, Eleme
     selectorCheckingContext.scope = !rootNode.isDocumentNode() ? &rootNode : 0;
     if (selectorCheckingContext.scope)
         selectorCheckingContext.scopeContainsLastMatchedElement = true;
-    return selectorChecker.match(selectorCheckingContext, DOMSiblingTraversalStrategy()) == SelectorChecker::SelectorMatches;
+    return selectorChecker.match(selectorCheckingContext) == SelectorChecker::SelectorMatches;
 }
 
 bool SelectorDataList::matches(Element& targetElement) const