Add 'error' property to exceptions thrown via Worker::importScripts.

Source/bindings/v8/WorkerScriptController.h

 /*
  * Copyright (C) 2009, 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 40 matching lines @@
             , lineNumber(0)
             , columnNumber(0)
         {
         }
 
         bool hadException;
         String errorMessage;
         int lineNumber;
         int columnNumber;
         String sourceURL;
+        ScriptValue exception;
     };
 
     class WorkerScriptController {
     public:
         WorkerScriptController(WorkerGlobalScope*);
         ~WorkerScriptController();
 
         WorkerGlobalScope* workerGlobalScope() { return m_workerGlobalScope; }
 
         void evaluate(const ScriptSourceCode&, RefPtr<ErrorEvent>* = 0);
@@ skipping 41 matching lines @@
         OwnPtr<DOMDataStore> m_domDataStore;
         bool m_executionForbidden;
         bool m_executionScheduledToTerminate;
         mutable Mutex m_scheduledTerminationMutex;
         RefPtr<ErrorEvent> m_errorEventFromImportedScript;
     };
 
 } // namespace WebCore
 
 #endif // WorkerScriptController_h