Tried using CrossThreadPersistent for workerDebuggerAgents

Source/core/inspector/InspectorApplicationCacheAgent.cpp

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  * 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 182 matching lines @@
     if (resourceInfo.m_isExplicit)
         builder.append("Explicit ");
 
     RefPtr<TypeBuilder::ApplicationCache::ApplicationCacheResource> value = TypeBuilder::ApplicationCache::ApplicationCacheResource::create()
         .setUrl(resourceInfo.m_resource.string())
         .setSize(static_cast<int>(resourceInfo.m_size))
         .setType(builder.toString());
     return value;
 }
 
+void InspectorApplicationCacheAgent::trace(Visitor* visitor)
+{
+    visitor->trace(m_pageAgent);
+    InspectorBaseAgent::trace(visitor);
+}
+
 } // namespace WebCore