Tried using CrossThreadPersistent for workerDebuggerAgents

Source/core/inspector/InspectorDebuggerAgent.h

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010-2011 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.
@@ skipping 53 matching lines @@
 class ScriptDebugServer;
 class ScriptRegexp;
 class ScriptSourceCode;
 class ScriptValue;
 class ThreadableLoaderClient;
 class XMLHttpRequest;
 
 typedef String ErrorString;
 
 class InspectorDebuggerAgent : public InspectorBaseAgent<InspectorDebuggerAgent>, public ScriptDebugListener, public InspectorBackendDispatcher::DebuggerCommandHandler {
-    WTF_MAKE_NONCOPYABLE(InspectorDebuggerAgent); WTF_MAKE_FAST_ALLOCATED;
+    WTF_MAKE_NONCOPYABLE(InspectorDebuggerAgent);
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     enum BreakpointSource {
         UserBreakpointSource,
         DebugCommandBreakpointSource,
         MonitorCommandBreakpointSource
     };
 
     static const char backtraceObjectGroup[];
 
     virtual ~InspectorDebuggerAgent();
@@ skipping 156 matching lines @@
     int m_skipStepInCount;
     bool m_skipAllPauses;
     OwnPtr<ScriptRegexp> m_cachedSkipStackRegExp;
     AsyncCallStackTracker m_asyncCallStackTracker;
 };
 
 } // namespace WebCore
 
 
 #endif // !defined(InspectorDebuggerAgent_h)