Remove Node Document friend relationship

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)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 1055 matching lines @@
 #if !ENABLE(OILPAN)
     virtual void dispose() override;
 #endif
 
     virtual PassRefPtrWillBeRawPtr<Document> cloneDocumentWithoutChildren();
 
     bool importContainerNodeChildren(ContainerNode* oldContainerNode, PassRefPtrWillBeRawPtr<ContainerNode> newContainerNode, ExceptionState&);
     void lockCompatibilityMode() { m_compatibilityModeLocked = true; }
 
 private:
-    friend class Node;
     friend class IgnoreDestructiveWriteCountIncrementer;
 
     bool isDocumentFragment() const = delete; // This will catch anyone doing an unnecessary check.
     bool isDocumentNode() const = delete; // This will catch anyone doing an unnecessary check.
     bool isElementNode() const = delete; // This will catch anyone doing an unnecessary check.
 
     ScriptedAnimationController& ensureScriptedAnimationController();
     virtual SecurityContext& securityContext() override final { return *this; }
     virtual EventQueue* eventQueue() const override final;
 
@@ skipping 338 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h