Oilpan: dispose an HTMLImportsController on document detach/removal.

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 35 matching lines @@
 //
 // An import tree node subclas to encapsulate imported document
 // lifecycle. This class is owned by HTMLImportsController. The actual loading
 // is done by HTMLImportLoader, which can be shared among multiple
 // HTMLImportChild of same link URL.
 //
 class HTMLImportChild final : public HTMLImport {
 public:
     HTMLImportChild(const KURL&, HTMLImportLoader*, SyncMode);
     virtual ~HTMLImportChild();
+    void dispose();
 
     HTMLLinkElement* link() const;
     const KURL& url() const { return m_url; }
 
     void ownerInserted();
     void didShareLoader();
     void didStartLoading();
 #if !ENABLE(OILPAN)
-    void importDestroyed();
     WeakPtr<HTMLImportChild> weakPtr() { return m_weakFactory.createWeakPtr(); }
 #endif
 
     // HTMLImport
     virtual Document* document() const override;
     virtual bool isDone() const override;
     virtual HTMLImportLoader* loader() const override;
     virtual void stateWillChange() override;
     virtual void stateDidChange() override;
     DECLARE_VIRTUAL_TRACE();
@@ skipping 28 matching lines @@
 
 inline HTMLImportChild* toHTMLImportChild(HTMLImport* import)
 {
     ASSERT(!import || !import->isRoot());
     return static_cast<HTMLImportChild*>(import);
 }
 
 } // namespace blink
 
 #endif // HTMLImportChild_h