Simplify ServiceWorkerContainer's access to its window.

Source/modules/serviceworkers/ServiceWorkerContainer.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 46 matching lines @@
 
 namespace WebCore {
 
 PassRefPtr<ServiceWorkerContainer> ServiceWorkerContainer::create(ExecutionContext* executionContext)
 {
     return adoptRef(new ServiceWorkerContainer(executionContext));
 }
 
 ServiceWorkerContainer::~ServiceWorkerContainer()
 {
+    ASSERT(!m_provider);
 }
 
 void ServiceWorkerContainer::detachClient()
 {
     if (m_provider) {
         m_provider->setClient(0);
         m_provider = 0;
     }
 }
 
@@ skipping 105 matching lines @@
 {
     if (!executionContext()) {
         deleteIfNoExistingOwner(serviceWorker);
         return;
     }
     m_controller = ServiceWorker::from(executionContext(), serviceWorker);
 }
 
 void ServiceWorkerContainer::dispatchMessageEvent(const blink::WebString& message, const blink::WebMessagePortChannelArray& webChannels)
 {
-    if (!executionContext() || !window())
+    if (!executionContext() || !executionContext()->executingWindow())
         return;
 
     OwnPtr<MessagePortArray> ports = MessagePort::toMessagePortArray(executionContext(), webChannels);
     RefPtr<SerializedScriptValue> value = SerializedScriptValue::createFromWire(message);
-    window()->dispatchEvent(MessageEvent::create(ports.release(), value));
+    executionContext()->executingWindow()->dispatchEvent(MessageEvent::create(ports.release(), value));
 }
 
 ServiceWorkerContainer::ServiceWorkerContainer(ExecutionContext* executionContext)
     : ContextLifecycleObserver(executionContext)
-    , DOMWindowLifecycleObserver(executionContext->isDocument() ? toDocument(executionContext)->domWindow() : 0)
     , m_provider(0)
 {
     ScriptWrappable::init(this);
 
     if (!executionContext)
         return;
 
     if (ServiceWorkerContainerClient* client = ServiceWorkerContainerClient::from(executionContext)) {
         m_provider = client->provider();
         if (m_provider)
             m_provider->setClient(this);
     }
 }
 
 } // namespace WebCore