Don't be so CRASH happy in the bindings layer.

WebCore/bindings/js/WorkerScriptController.h

Index: WebCore/bindings/js/WorkerScriptController.h
===================================================================
--- WebCore/bindings/js/WorkerScriptController.h	(revision 109601)
+++ WebCore/bindings/js/WorkerScriptController.h	(working copy)
@@ -67,6 +67,7 @@
         // forbidExecution()/isExecutionForbidden() to guard against reentry into JS.
         // Can be called from any thread.
         void scheduleExecutionTermination();
+        bool isExecutionTerminating() const;
 
         // Called on Worker thread when JS exits with termination exception caused by forbidExecution() request,
         // or by Worker thread termination code to prevent future entry into JS.
@@ -89,6 +90,7 @@
         WorkerContext* m_workerContext;
         JSC::Strong<JSWorkerContext> m_workerContextWrapper;
         bool m_executionForbidden;
+        mutable Mutex m_scheduledTerminationMutex;
     };
 
 } // namespace WebCore