Fix SharedWorker leak when script load has failed.

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 160 matching lines @@
 
     m_webView->close();
     m_mainFrame->close();
 }
 
 void WebSharedWorkerImpl::stopWorkerThread()
 {
     if (m_askedToTerminate)
         return;
     m_askedToTerminate = true;
+
+    bool noPendingActivity = true;

[tkent, 2014/07/28 06:47:44]

Negative variable is not good for code readability.  hasPendingActivity?

     if (m_mainScriptLoader) {
         m_mainScriptLoader->cancel();
         m_mainScriptLoader.clear();
+        noPendingActivity = false;
     }
-    if (m_workerThread)
+    if (m_workerThread) {
         m_workerThread->stop();
+        noPendingActivity = false;
+    }
+
+    if (noPendingActivity) {
+        // If there are no active WorkerThread, |workerGlobalScopeClosed()|
+        // call back to delete this is never called, so we should clean up here.
+        delete this;
+    }
 }
 
 void WebSharedWorkerImpl::initializeLoader(const WebURL& url)
 {
     // Create 'shadow page'. This page is never displayed, it is used to proxy the
     // loading requests from the worker context to the rest of WebKit and Chromium
     // infrastructure.
     ASSERT(!m_webView);
     m_webView = WebView::create(0);
     m_webView->settings()->setOfflineWebApplicationCacheEnabled(RuntimeEnabledFeatures::applicationCacheEnabled());
@@ skipping 251 matching lines @@
     workerThread()->postDebuggerTask(createCrossThreadTask(dispatchOnInspectorBackendTask, String(message)));
     workerThread()->interruptAndDispatchInspectorCommands();
 }
 
 WebSharedWorker* WebSharedWorker::create(WebSharedWorkerClient* client)
 {
     return new WebSharedWorkerImpl(client);
 }
 
 } // namespace blink