Oilpan: make DOMWindowProperty a GC mixin.

Source/core/loader/appcache/ApplicationCache.h

Index: Source/core/loader/appcache/ApplicationCache.h
diff --git a/Source/core/loader/appcache/ApplicationCache.h b/Source/core/loader/appcache/ApplicationCache.h
index 75f66106dafb2590fe06ae43b176997569acdc85..7a6809566e0fe770632af37deff5a7ddca6b11f3 100644
--- a/Source/core/loader/appcache/ApplicationCache.h
+++ b/Source/core/loader/appcache/ApplicationCache.h
@@ -49,7 +49,12 @@ public:
     {
         return adoptRefWillBeNoop(new ApplicationCache(frame));
     }
-    virtual ~ApplicationCache() { ASSERT(!m_frame); }
+    virtual ~ApplicationCache()
+    {
+#if !ENABLE(OILPAN)

[haraken, 2014/09/10 02:49:36]

I'm OK with this, but the ASSERT(!m_frame) is still valid until you move the
Frame to the heap in the next patch, right?

[sof, 2014/09/10 05:49:40]

It should be.

+        ASSERT(!m_frame);
+#endif
+    }
 
     virtual void willDestroyGlobalObjectInFrame() OVERRIDE;
 
@@ -74,6 +79,8 @@ public:
 
     static const AtomicString& toEventType(ApplicationCacheHost::EventID);
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 private:
     explicit ApplicationCache(LocalFrame*);