bindings/oilpan: Stops using ScriptWrappable pointers already collected by GC.

Source/bindings/core/v8/WrapperTypeInfo.h

Index: Source/bindings/core/v8/WrapperTypeInfo.h
diff --git a/Source/bindings/core/v8/WrapperTypeInfo.h b/Source/bindings/core/v8/WrapperTypeInfo.h
index 95a1f9f58c44f40e35467986a4f1577a5100104b..41099ee67b6d8bfb216d870a7bc036217a84a834 100644
--- a/Source/bindings/core/v8/WrapperTypeInfo.h
+++ b/Source/bindings/core/v8/WrapperTypeInfo.h
@@ -126,30 +126,33 @@ struct WrapperTypeInfo {
         return domTemplateFunction(isolate);
     }
 
-    void refObject(ScriptWrappable* scriptWrappable) const
+    bool isGarbageCollected() const
     {
-        if (gcType == GarbageCollectedObject) {
-            ThreadState::current()->persistentAllocated();
-        } else if (gcType == WillBeGarbageCollectedObject) {
+        return (gcType == GarbageCollectedObject
 #if ENABLE(OILPAN)
-            ThreadState::current()->persistentAllocated();
+                || gcType == WillBeGarbageCollectedObject
 #endif
+                );
+    }
+
+    void refObject(ScriptWrappable* scriptWrappable) const
+    {
+        if (isGarbageCollected()) {
+            ThreadState::current()->persistentAllocated();
+        } else {
+            ASSERT(refObjectFunction);
+            refObjectFunction(scriptWrappable);
         }
-        ASSERT(refObjectFunction);
-        refObjectFunction(scriptWrappable);
     }
 
     void derefObject(ScriptWrappable* scriptWrappable) const
     {
-        if (gcType == GarbageCollectedObject) {
+        if (isGarbageCollected()) {
             ThreadState::current()->persistentFreed();
-        } else if (gcType == WillBeGarbageCollectedObject) {
-#if ENABLE(OILPAN)
-            ThreadState::current()->persistentFreed();
-#endif
+        } else {
+            ASSERT(derefObjectFunction);
+            derefObjectFunction(scriptWrappable);
         }
-        ASSERT(derefObjectFunction);
-        derefObjectFunction(scriptWrappable);
     }
 
     void trace(Visitor* visitor, ScriptWrappable* scriptWrappable) const