Rollback transactions by observing them weakly from DatabaseSync.

Source/modules/webdatabase/DatabaseSync.h

Index: Source/modules/webdatabase/DatabaseSync.h
diff --git a/Source/modules/webdatabase/DatabaseSync.h b/Source/modules/webdatabase/DatabaseSync.h
index 07052c87ae1daa2a5dbb7253d9e1296b343fe0f2..5304d74c1384a4d6e7d050e341b596902be62bd9 100644
--- a/Source/modules/webdatabase/DatabaseSync.h
+++ b/Source/modules/webdatabase/DatabaseSync.h
@@ -76,12 +76,30 @@ private:
     static PassRefPtrWillBeRawPtr<DatabaseSync> create(ExecutionContext*, PassRefPtrWillBeRawPtr<DatabaseBackendBase>);
 
     void runTransaction(PassOwnPtr<SQLTransactionSyncCallback>, bool readOnly, ExceptionState&);
-    void rollbackTransaction(PassRefPtr<SQLTransactionSync>);
+    void rollbackTransaction(SQLTransactionSync&);
 
     String m_lastErrorMessage;
 
     friend class DatabaseManager;
     friend class DatabaseServer; // FIXME: remove this when the backend has been split out.
+
+#if ENABLE(OILPAN)
+public:
+    void registerTransaction(SQLTransactionSync*);
+
+private:
+    class TransactionObserver {
+    public:
+        TransactionObserver(SQLTransactionSync* sync) : m_sync(sync) { }
+        ~TransactionObserver();

[zerny-chromium, 2014/03/17 09:27:00]

private:

+        SQLTransactionSync* m_sync;
+    };
+
+    typedef PersistentHeapHashMap<WeakMember<SQLTransactionSync>, OwnPtr<TransactionObserver> > ObserverMap;
+    GC_PLUGIN_IGNORE("http://crbug.com/353083")
+    ObserverMap m_observers;
+#endif
+
 };
 
 } // namespace WebCore