Oilpan: Prepare to move SQLTransactionWrapper and CangeVersionWrapper to Oilpan heap.

Source/modules/webdatabase/ChangeVersionWrapper.h

Index: Source/modules/webdatabase/ChangeVersionWrapper.h
diff --git a/Source/modules/webdatabase/ChangeVersionWrapper.h b/Source/modules/webdatabase/ChangeVersionWrapper.h
index a0b2c300c95405aab8b02b723f25532040dd1959..660d3b608cf69fce42b57a87a95f175e99259e96 100644
--- a/Source/modules/webdatabase/ChangeVersionWrapper.h
+++ b/Source/modules/webdatabase/ChangeVersionWrapper.h
@@ -38,8 +38,9 @@ class SQLErrorData;
 
 class ChangeVersionWrapper FINAL : public SQLTransactionWrapper {
 public:
-    static PassRefPtr<ChangeVersionWrapper> create(const String& oldVersion, const String& newVersion) { return adoptRef(new ChangeVersionWrapper(oldVersion, newVersion)); }
+    static PassRefPtrWillBeRawPtr<ChangeVersionWrapper> create(const String& oldVersion, const String& newVersion) { return adoptRefWillBeNoop(new ChangeVersionWrapper(oldVersion, newVersion)); }
 
+    virtual void trace(Visitor*) OVERRIDE { }
     virtual bool performPreflight(SQLTransactionBackend*) OVERRIDE;
     virtual bool performPostflight(SQLTransactionBackend*) OVERRIDE;
     virtual SQLErrorData* sqlError() const OVERRIDE { return m_sqlError.get(); }