Tried using CrossThreadPersistent for workerDebuggerAgents

Source/core/inspector/InspectorDOMDebuggerAgent.h

Index: Source/core/inspector/InspectorDOMDebuggerAgent.h
diff --git a/Source/core/inspector/InspectorDOMDebuggerAgent.h b/Source/core/inspector/InspectorDOMDebuggerAgent.h
index fe2ee7cbc05223667b4217cdc023898c605247b5..66a039839d839943cc20d1fe81650c80dc37ddf5 100644
--- a/Source/core/inspector/InspectorDOMDebuggerAgent.h
+++ b/Source/core/inspector/InspectorDOMDebuggerAgent.h
@@ -61,9 +61,10 @@ class InspectorDOMDebuggerAgent FINAL :
     public InspectorBackendDispatcher::DOMDebuggerCommandHandler {
     WTF_MAKE_NONCOPYABLE(InspectorDOMDebuggerAgent);
 public:
-    static PassOwnPtr<InspectorDOMDebuggerAgent> create(InspectorDOMAgent*, InspectorDebuggerAgent*);
+    static PassOwnPtrWillBeRawPtr<InspectorDOMDebuggerAgent> create(InspectorDOMAgent*, InspectorDebuggerAgent*);
 
     virtual ~InspectorDOMDebuggerAgent();
+    virtual void trace(Visitor*) OVERRIDE;
 
     // DOMDebugger API for InspectorFrontend
     virtual void setXHRBreakpoint(ErrorString*, const String& url) OVERRIDE;
@@ -125,8 +126,8 @@ private:
 
     void clear();
 
-    InspectorDOMAgent* m_domAgent;
-    InspectorDebuggerAgent* m_debuggerAgent;
+    RawPtrWillBeMember<InspectorDOMAgent> m_domAgent;
+    RawPtrWillBeMember<InspectorDebuggerAgent> m_debuggerAgent;
     HashMap<Node*, uint32_t> m_domBreakpoints;
     bool m_pauseInNextEventListener;
 };