[ServiceWorker] Fix ResourceFetcher::isControlledByServiceWorker to support HTMLImports.

Source/core/fetch/ResourceFetcher.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 601 matching lines @@
         return false;
     }
     return true;
 }
 
 bool ResourceFetcher::isControlledByServiceWorker() const
 {
     LocalFrame* localFrame = frame();
     if (!localFrame)
         return false;
-    if (!m_documentLoader)
-        return false;
-    return localFrame->loader().client()->isControlledByServiceWorker(*m_documentLoader);
+    ASSERT(m_documentLoader || localFrame->loader().documentLoader());
+    if (m_documentLoader)
+        return localFrame->loader().client()->isControlledByServiceWorker(*m_documentLoader);
+    // m_documentLoader is null while loading resources from the imported HTML.
+    // In such cases whether the request is controlled by ServiceWorker or not
+    // is determined by the document loader of the frame.
+    return localFrame->loader().client()->isControlledByServiceWorker(*localFrame->loader().documentLoader());
 }
 
 bool ResourceFetcher::shouldLoadNewResource(Resource::Type type) const
 {
     if (!frame())
         return false;
     if (!m_documentLoader)
         return true;
     if (type == Resource::MainResource)
         return m_documentLoader == frame()->loader().provisionalDocumentLoader();
@@ skipping 909 matching lines @@
 
 void ResourceFetcher::trace(Visitor* visitor)
 {
     visitor->trace(m_document);
     visitor->trace(m_loaders);
     visitor->trace(m_multipartLoaders);
     ResourceLoaderHost::trace(visitor);
 }
 
 }