[HTML Imports] Make HTMLLinkElement.import a Document.

Source/core/html/HTMLLinkElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 155 matching lines @@
     return static_cast<LinkStyle*>(m_link.get());
 }
 
 LinkImport* HTMLLinkElement::linkImport() const
 {
     if (!m_link || m_link->type() != LinkResource::Import)
         return 0;
     return static_cast<LinkImport*>(m_link.get());
 }
 
-DocumentFragment* HTMLLinkElement::import() const
+Document* HTMLLinkElement::import() const
 {
     if (LinkImport* link = linkImport())
-        return linkImport()->importedFragment();
+        return linkImport()->importedDocument();
     return 0;
 }
 
 void HTMLLinkElement::process()
 {
     if (LinkResource* link = linkResourceToProcess())
         link->process();
 }
 
 Node::InsertionNotificationRequest HTMLLinkElement::insertedInto(ContainerNode* insertionPoint)
@@ skipping 421 matching lines @@
 void LinkStyle::ownerRemoved()
 {
     if (m_sheet)
         clearSheet();
 
     if (styleSheetIsLoading())
         removePendingSheet(RemovePendingSheetNotifyLater);
 }
 
 } // namespace WebCore