Oilpan: fix build after r177450.

Source/bindings/core/v8/ScriptPromiseProperty.h

Index: Source/bindings/core/v8/ScriptPromiseProperty.h
diff --git a/Source/bindings/core/v8/ScriptPromiseProperty.h b/Source/bindings/core/v8/ScriptPromiseProperty.h
index ee1ac627c8ca490f4163388866cb384b830dc3a2..c5ca57f3838c1a26ed31ea795430fbfe97a1e383 100644
--- a/Source/bindings/core/v8/ScriptPromiseProperty.h
+++ b/Source/bindings/core/v8/ScriptPromiseProperty.h
@@ -62,6 +62,8 @@ public:
     template<typename PassRejectedType>
     void reject(PassRejectedType);
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 private:
     template<typename PassHolderType>
     ScriptPromiseProperty(ExecutionContext*, PassHolderType, Name);
@@ -79,7 +81,7 @@ template<typename HolderType, typename ResolvedType, typename RejectedType>
 template<typename PassHolderType>
 PassRefPtrWillBeRawPtr<ScriptPromiseProperty<HolderType, ResolvedType, RejectedType> > ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::create(ExecutionContext* executionContext, PassHolderType holder, Name name)
 {
-    return adoptRef(new ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>(executionContext, holder, name));
+    return adoptRefWillBeRefCountedGarbageCollected(new ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>(executionContext, holder, name));
 }
 
 template<typename HolderType, typename ResolvedType, typename RejectedType>
@@ -139,6 +141,13 @@ v8::Handle<v8::Value> ScriptPromiseProperty<HolderType, ResolvedType, RejectedTy
     return V8ValueTraits<RejectedType>::toV8Value(m_rejected, creationContext, isolate);
 }
 
+template<typename HolderType, typename ResolvedType, typename RejectedType>
+void ScriptPromiseProperty<HolderType, ResolvedType, RejectedType>::trace(Visitor* visitor)
+{
+    visitor->trace(m_holder);
+    ScriptPromisePropertyBase::trace(visitor);
+}
+
 } // namespace WebCore
 
 #endif // ScriptPromiseProperty_h