Support Document constructor.

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 243 matching lines @@
                              public ExecutionContext,
                              public SynchronousMutationNotifier,
                              public Supplementable<Document> {
   DEFINE_WRAPPERTYPEINFO();
   USING_GARBAGE_COLLECTED_MIXIN(Document);
 
  public:
   static Document* Create(const DocumentInit& initializer = DocumentInit()) {
     return new Document(initializer);
   }
+  // Factory for web-exposed Document constructor. The argument document must be
+  // a document instance representing window.document, and it works as the
+  // source of ExecutionContext and security origin of the new document.
+  // https://dom.spec.whatwg.org/#dom-document-document
+  static Document* Create(const Document&);
   ~Document() override;
 
   MediaQueryMatcher& GetMediaQueryMatcher();
 
   void MediaQueryAffectingValueChanged();
 
   using SecurityContext::GetSecurityOrigin;
   using SecurityContext::GetContentSecurityPolicy;
   using TreeScope::getElementById;
 
@@ skipping 1471 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