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

Source/modules/webdatabase/SQLTransactionBackend.h

Index: Source/modules/webdatabase/SQLTransactionBackend.h
diff --git a/Source/modules/webdatabase/SQLTransactionBackend.h b/Source/modules/webdatabase/SQLTransactionBackend.h
index abdd1cf1e46cf2989bd9dfb247c5ee2447f20087..3ef564c5ca68ea85464114e1bd6db6ba899233d8 100644
--- a/Source/modules/webdatabase/SQLTransactionBackend.h
+++ b/Source/modules/webdatabase/SQLTransactionBackend.h
@@ -48,9 +48,10 @@ class SQLStatementBackend;
 class SQLTransactionBackend;
 class SQLValue;
 
-class SQLTransactionWrapper : public ThreadSafeRefCounted<SQLTransactionWrapper> {
+class SQLTransactionWrapper : public ThreadSafeRefCountedWillBeGarbageCollectedFinalized<SQLTransactionWrapper> {
 public:
     virtual ~SQLTransactionWrapper() { }
+    virtual void trace(Visitor*) = 0;
     virtual bool performPreflight(SQLTransactionBackend*) = 0;
     virtual bool performPostflight(SQLTransactionBackend*) = 0;
     virtual SQLErrorData* sqlError() const = 0;
@@ -60,7 +61,7 @@ public:
 class SQLTransactionBackend FINAL : public AbstractSQLTransactionBackend, public SQLTransactionStateMachine<SQLTransactionBackend> {
 public:
     static PassRefPtrWillBeRawPtr<SQLTransactionBackend> create(DatabaseBackend*,
-        PassRefPtrWillBeRawPtr<AbstractSQLTransaction>, PassRefPtr<SQLTransactionWrapper>, bool readOnly);
+        PassRefPtrWillBeRawPtr<AbstractSQLTransaction>, PassRefPtrWillBeRawPtr<SQLTransactionWrapper>, bool readOnly);
 
     virtual ~SQLTransactionBackend();
     virtual void trace(Visitor*) OVERRIDE;
@@ -74,7 +75,7 @@ public:
 
 private:
     SQLTransactionBackend(DatabaseBackend*, PassRefPtrWillBeRawPtr<AbstractSQLTransaction>,
-        PassRefPtr<SQLTransactionWrapper>, bool readOnly);
+        PassRefPtrWillBeRawPtr<SQLTransactionWrapper>, bool readOnly);
 
     // APIs called from the frontend published via AbstractSQLTransactionBackend:
     virtual void requestTransitToState(SQLTransactionState) OVERRIDE;
@@ -113,7 +114,7 @@ private:
     RefPtrWillBeMember<SQLStatementBackend> m_currentStatementBackend;
 
     RefPtrWillBeMember<DatabaseBackend> m_database;
-    RefPtr<SQLTransactionWrapper> m_wrapper;
+    RefPtrWillBeMember<SQLTransactionWrapper> m_wrapper;
     OwnPtr<SQLErrorData> m_transactionError;
 
     bool m_hasCallback;