Invoke WorkerScriptLoader's m_finishedCallback callback safely.

Source/web/WebSharedWorkerImpl.cpp

 /*
  * Copyright (C) 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 182 matching lines @@
     m_networkProvider = adoptPtr(m_client->createServiceWorkerNetworkProvider(frame->dataSource()));
     m_mainScriptLoader = adoptPtr(new WorkerScriptLoader());
     m_mainScriptLoader->setRequestContext(WebURLRequest::RequestContextSharedWorker);
     m_loadingDocument = toWebLocalFrameImpl(frame)->frame()->document();
     m_mainScriptLoader->loadAsynchronously(
         *m_loadingDocument.get(),
         m_url,
         DenyCrossOriginRequests,
         bind(&WebSharedWorkerImpl::didReceiveScriptLoaderResponse, this),
         bind(&WebSharedWorkerImpl::onScriptLoaderFinished, this));
+    // Do nothing here since onScriptLoaderFinished() might be already invoked

[haraken, 2015/07/02 06:18:06]

might be => might have been

[Takashi Toyoshima, 2015/07/02 07:33:56]

Done.

+    // and |this| might have been deleted at this point.
 }
 
 bool WebSharedWorkerImpl::isControlledByServiceWorker(WebDataSource& dataSource)
 {
     return m_networkProvider && m_networkProvider->isControlledByServiceWorker(dataSource);
 }
 
 int64_t WebSharedWorkerImpl::serviceWorkerID(WebDataSource& dataSource)
 {
     if (!m_networkProvider)
@@ skipping 198 matching lines @@
     if (devtoolsAgent)
         devtoolsAgent->dispatchOnInspectorBackend(message);
 }
 
 WebSharedWorker* WebSharedWorker::create(WebSharedWorkerClient* client)
 {
     return new WebSharedWorkerImpl(client);
 }
 
 } // namespace blink