Oilpan: Prepare to move SQLTransactionBackendSync and SQLTransactionSync to Oilpan heap.

Source/modules/webdatabase/DatabaseSync.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 44 matching lines @@
 class DatabaseSync FINAL : public DatabaseBackendSync, public DatabaseBase, public ScriptWrappable {
 public:
     virtual ~DatabaseSync();
     virtual void trace(Visitor*) OVERRIDE;
 
     void changeVersion(const String& oldVersion, const String& newVersion, PassOwnPtr<SQLTransactionSyncCallback>, ExceptionState&);
     void transaction(PassOwnPtr<SQLTransactionSyncCallback>, ExceptionState&);
     void readTransaction(PassOwnPtr<SQLTransactionSyncCallback>, ExceptionState&);
 
     virtual void closeImmediately() OVERRIDE;
+    void observeTransaction(SQLTransactionSync&);
 
     const String& lastErrorMessage() const { return m_lastErrorMessage; }
     void setLastErrorMessage(const String& message) { m_lastErrorMessage = message; }
     void setLastErrorMessage(const char* message, int sqliteCode, const char* sqliteMessage)
     {
         setLastErrorMessage(String::format("%s (%d, %s)", message, sqliteCode, sqliteMessage));
     }
 
 private:
     DatabaseSync(PassRefPtr<DatabaseContext>, const String& name,
         const String& expectedVersion, const String& displayName, unsigned long estimatedSize);
     static PassRefPtrWillBeRawPtr<DatabaseSync> create(ExecutionContext*, PassRefPtrWillBeRawPtr<DatabaseBackendBase>);
 
     void runTransaction(PassOwnPtr<SQLTransactionSyncCallback>, bool readOnly, ExceptionState&);
-    void rollbackTransaction(PassRefPtr<SQLTransactionSync>);
+    void rollbackTransaction(SQLTransactionSync&);
+#if ENABLE(OILPAN)
+    class TransactionObserver {
+    public:
+        explicit TransactionObserver(SQLTransactionSync& transaction) : m_transaction(transaction) { }
+        ~TransactionObserver();
+
+    private:
+        SQLTransactionSync& m_transaction;
+    };
+
+    GC_PLUGIN_IGNORE("http://crbug.com/353083")
+    PersistentHeapHashMap<WeakMember<SQLTransactionSync>, OwnPtr<TransactionObserver> > m_observers;

[haraken, 2014/03/18 09:59:09]

I'd like to have a comment about why this needs to be persistent.

[zerny-chromium, 2014/03/18 10:09:09]

I think the bug report provides sufficient documentation here.

[haraken, 2014/03/18 11:31:33]

I want to have a comment about the threading issue of this specific case. I
couldn't get it until mads explained it in the issue tracker :)

[tkent, 2014/03/19 04:58:39]

I'll add a comment.

+#endif
 
     String m_lastErrorMessage;
 
     friend class DatabaseManager;
     friend class DatabaseServer; // FIXME: remove this when the backend has been split out.
 };
 
 } // namespace WebCore
 
 #endif