Remove virtualized isRoot/isChild from HTMLImport.

Source/core/html/imports/HTMLImportChild.h

 /*
  * 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 47 matching lines @@
     HTMLLinkElement* link() const;
     Document* importedDocument() const;
     const KURL& url() const { return m_url; }
 
     void didShareLoader();
     void didStartLoading();
     void importDestroyed();
     WeakPtr<HTMLImportChild> weakPtr() { return m_weakFactory.createWeakPtr(); }
 
     // HTMLImport
-    virtual bool isChild() const OVERRIDE { return true; }
     virtual Document* document() const OVERRIDE;
     virtual bool isDone() const OVERRIDE;
     virtual HTMLImportLoader* loader() const OVERRIDE { return m_loader; }
     virtual void stateWillChange() OVERRIDE;
     virtual void stateDidChange() OVERRIDE;
 
 #if !defined(NDEBUG)
     virtual void showThis() OVERRIDE;
 #endif
 
@@ skipping 14 matching lines @@
 
     KURL m_url;
     WeakPtrFactory<HTMLImportChild> m_weakFactory;
     WeakPtr<CustomElementMicrotaskImportStep> m_customElementMicrotaskStep;
     HTMLImportLoader* m_loader;
     HTMLImportChildClient* m_client;
 };
 
 inline HTMLImportChild* toHTMLImportChild(HTMLImport* import)
 {
-    ASSERT(!import || import->isChild());
+    ASSERT(!import || !import->isRoot());
     return static_cast<HTMLImportChild*>(import);
 }
 
 } // namespace WebCore
 
 #endif // HTMLImportChild_h