Have WorkerScriptController::workerGlobalScope return a reference

Source/bindings/v8/V8Utilities.cpp

 /*
  * Copyright (C) 2008, 2009 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 138 matching lines @@
                 removeHiddenDependency(object, oldListenerObject, cacheIndex, isolate);
         }
     }
     if (!newValue->IsNull() && !newValue->IsUndefined())
         createHiddenDependency(object, newValue, cacheIndex, isolate);
 }
 
 ExecutionContext* getExecutionContext()
 {
     if (WorkerScriptController* controller = WorkerScriptController::controllerForContext())
-        return controller->workerGlobalScope();
+        return &controller->workerGlobalScope();
 
     return currentDocument();
 }
 
 } // namespace WebCore