Oilpan: turn DOMWindow into a heap supplementable.

Source/modules/indexeddb/DOMWindowIndexedDatabase.h

Index: Source/modules/indexeddb/DOMWindowIndexedDatabase.h
diff --git a/Source/modules/indexeddb/DOMWindowIndexedDatabase.h b/Source/modules/indexeddb/DOMWindowIndexedDatabase.h
index ebec8a4e78b17274b496c007db1b154afa158fcc..58bc14b21d5a9c2677c34332057339d6e1e31e29 100644
--- a/Source/modules/indexeddb/DOMWindowIndexedDatabase.h
+++ b/Source/modules/indexeddb/DOMWindowIndexedDatabase.h
@@ -35,7 +35,8 @@ namespace WebCore {
 class IDBFactory;
 class DOMWindow;
 
-class DOMWindowIndexedDatabase FINAL : public DOMWindowProperty, public Supplement<DOMWindow> {
+class DOMWindowIndexedDatabase FINAL : public NoBaseWillBeGarbageCollectedFinalized<DOMWindowIndexedDatabase>, public WillBeHeapSupplement<DOMWindow>, public DOMWindowProperty {
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(DOMWindowIndexedDatabase);
 public:
     virtual ~DOMWindowIndexedDatabase();
     static DOMWindowIndexedDatabase& from(DOMWindow&);
@@ -45,6 +46,8 @@ public:
     virtual void willDestroyGlobalObjectInFrame() OVERRIDE;
     virtual void willDetachGlobalObjectFromFrame() OVERRIDE;
 
+    void trace(Visitor*) { }
+
 private:
     explicit DOMWindowIndexedDatabase(DOMWindow&);