Oilpan: Move SelectorFilter to oilpan's heap

Source/core/css/SelectorFilter.cpp

Index: Source/core/css/SelectorFilter.cpp
diff --git a/Source/core/css/SelectorFilter.cpp b/Source/core/css/SelectorFilter.cpp
index 66abefc2b78fc9877100d6d20f074b7cab1d4b36..defae874bb55808dba822aa6a014ed9a80de4ee3 100644
--- a/Source/core/css/SelectorFilter.cpp
+++ b/Source/core/css/SelectorFilter.cpp
@@ -170,4 +170,14 @@ void SelectorFilter::collectIdentifierHashes(const CSSSelector& selector, unsign
     *hash = 0;
 }
 
+void SelectorFilter::ParentStackFrame::trace(Visitor* visitor)
+{
+    visitor->trace(element);
+}
+
+void SelectorFilter::trace(Visitor* visitor)
+{
+    visitor->trace(m_parentStack);
+}
+
 }