Refactor setImportsController() to clarify invariants

third_party/WebKit/Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 1136 matching lines @@
       ScriptState*,
       const AtomicString& name,
       const ElementRegistrationOptions&,
       ExceptionState&,
       V0CustomElement::NameSet validNames = V0CustomElement::StandardNames);
   V0CustomElementRegistrationContext* registrationContext() {
     return m_registrationContext.get();
   }
   V0CustomElementMicrotaskRunQueue* customElementMicrotaskRunQueue();
 
-  void setImportsController(HTMLImportsController*);
+  void clearImportsController();
+  void createImportsController();
   HTMLImportsController* importsController() const {
     return m_importsController;
   }
   HTMLImportLoader* importLoader() const;
 
   bool haveImportsLoaded() const;
   void didLoadAllImports();
 
   void adjustFloatQuadsForScrollAndAbsoluteZoom(Vector<FloatQuad>&,
                                                 LayoutObject&);
@@ skipping 549 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLiveDocumentInstances();
 #endif
 
 #endif  // Document_h