Tried using CrossThreadPersistent for workerDebuggerAgents

Source/modules/webdatabase/InspectorDatabaseAgent.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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 31 matching lines @@
 class DocumentLoader;
 class LocalFrame;
 class InspectorDatabaseResource;
 class InspectorFrontend;
 class InstrumentingAgents;
 
 typedef String ErrorString;
 
 class InspectorDatabaseAgent FINAL : public InspectorBaseAgent<InspectorDatabaseAgent>, public InspectorBackendDispatcher::DatabaseCommandHandler {
 public:
-    static PassOwnPtr<InspectorDatabaseAgent> create()
+    static PassOwnPtrWillBeRawPtr<InspectorDatabaseAgent> create()
     {
-        return adoptPtr(new InspectorDatabaseAgent());
+        return adoptPtrWillBeNoop(new InspectorDatabaseAgent());
     }
     virtual ~InspectorDatabaseAgent();
+    virtual void trace(Visitor*) OVERRIDE;
 
     virtual void setFrontend(InspectorFrontend*) OVERRIDE;
     virtual void clearFrontend() OVERRIDE;
     virtual void restore() OVERRIDE;
 
     virtual void didCommitLoadForMainFrame() OVERRIDE;
 
     // Called from the front-end.
     virtual void enable(ErrorString*) OVERRIDE;
     virtual void disable(ErrorString*) OVERRIDE;
     virtual void getDatabaseTableNames(ErrorString*, const String& databaseId, RefPtr<TypeBuilder::Array<String> >& names) OVERRIDE;
     virtual void executeSQL(ErrorString*, const String& databaseId, const String& query, PassRefPtr<ExecuteSQLCallback>) OVERRIDE;
 
     void didOpenDatabase(PassRefPtrWillBeRawPtr<Database>, const String& domain, const String& name, const String& version);
 private:
     explicit InspectorDatabaseAgent();
 
     Database* databaseForId(const String& databaseId);
     InspectorDatabaseResource* findByFileName(const String& fileName);
 
     InspectorFrontend::Database* m_frontend;
-    typedef WillBePersistentHeapHashMap<String, RefPtrWillBeMember<InspectorDatabaseResource> > DatabaseResourcesHeapMap;
+    typedef WillBeHeapHashMap<String, RefPtrWillBeMember<InspectorDatabaseResource> > DatabaseResourcesHeapMap;
     DatabaseResourcesHeapMap m_resources;
     bool m_enabled;
 };
 
 } // namespace WebCore
 
 #endif // !defined(InspectorDatabaseAgent_h)