Oilpan: move DOM string collection objects to the Oilpan heap.

Source/core/html/ClassList.cpp

Index: Source/core/html/ClassList.cpp
diff --git a/Source/core/html/ClassList.cpp b/Source/core/html/ClassList.cpp
index ba44f7b0b0d1d5d2f8e53ad7d6e5c95150466ffa..431af7b703807afcb859e8300dd4e29911229a4a 100644
--- a/Source/core/html/ClassList.cpp
+++ b/Source/core/html/ClassList.cpp
@@ -32,6 +32,7 @@ using namespace HTMLNames;
 
 ClassList::ClassList(Element* element) : m_element(element) { }
 
+#if !ENABLE(OILPAN)
 void ClassList::ref()
 {
     m_element->ref();
@@ -41,6 +42,7 @@ void ClassList::deref()
 {
     m_element->deref();
 }
+#endif
 
 unsigned ClassList::length() const
 {
@@ -70,4 +72,10 @@ const SpaceSplitString& ClassList::classNames() const
     return m_element->elementData()->classNames();
 }
 
+void ClassList::trace(Visitor* visitor)
+{
+    visitor->trace(m_element);
+    DOMTokenList::trace(visitor);
+}
+
 } // namespace WebCore