Oilpan: move LiveNodeList collections to the heap.

Source/core/dom/ClassCollection.h

Index: Source/core/dom/ClassCollection.h
diff --git a/Source/core/dom/ClassCollection.h b/Source/core/dom/ClassCollection.h
index 257cbb3b837b2d151d8eedf559cdf9c269254401..0d340bedce1f31057c53ad13fbbe9df954e1fc27 100644
--- a/Source/core/dom/ClassCollection.h
+++ b/Source/core/dom/ClassCollection.h
@@ -40,10 +40,10 @@ class ClassCollection FINAL : public HTMLCollection {
 public:
     // classNames argument is an AtomicString because it is common for Elements to share the same class names.
     // It is also used to construct a SpaceSplitString (m_classNames) and its constructor requires an AtomicString.
-    static PassRefPtr<ClassCollection> create(ContainerNode& rootNode, CollectionType type, const AtomicString& classNames)
+    static PassRefPtrWillBeRawPtr<ClassCollection> create(ContainerNode& rootNode, CollectionType type, const AtomicString& classNames)
     {
         ASSERT_UNUSED(type, type == ClassCollectionType);
-        return adoptRef(new ClassCollection(rootNode, classNames));
+        return adoptRefWillBeNoop(new ClassCollection(rootNode, classNames));
     }
 
     virtual ~ClassCollection();