Make ThreadableLoader class to use references

Source/web/WebEmbeddedWorkerImpl.cpp

 /*
  * Copyright (C) 2013 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 56 matching lines @@
         return adoptPtr(new Loader());
     }
 
     virtual ~Loader()
     {
         m_scriptLoader->setClient(0);
     }
 
     void load(ExecutionContext* loadingContext, const KURL& scriptURL, const Closure& callback)
     {
+        ASSERT(loadingContext);
         m_callback = callback;
         m_scriptLoader->setTargetType(ResourceRequest::TargetIsServiceWorker);
         m_scriptLoader->loadAsynchronously(
-            loadingContext, scriptURL, DenyCrossOriginRequests, this);
+            *loadingContext, scriptURL, DenyCrossOriginRequests, this);
     }
 
     virtual void notifyFinished() OVERRIDE
     {
         m_callback();
     }
 
     void cancel()
     {
         m_scriptLoader->cancel();
@@ skipping 173 matching lines @@
     m_mainScriptLoader.clear();
 
     m_workerGlobalScopeProxy = ServiceWorkerGlobalScopeProxy::create(*this, *toWebFrameImpl(m_mainFrame)->frame()->document(), *contextClient);
     m_loaderProxy = LoaderProxy::create(*this);
 
     m_workerThread = ServiceWorkerThread::create(*m_loaderProxy, *m_workerGlobalScopeProxy, startupData.release());
     m_workerThread->start();
 }
 
 } // namespace blink