Support Document constructor.

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

 /*
  * 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, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 473 matching lines @@
 
   void UnregisterAsObserver(ExecutionContext* context) {
     DCHECK(context);
     GetNetworkStateNotifier().RemoveOnLineObserver(
         this, TaskRunnerHelper::Get(TaskType::kNetworking, context));
   }
 
   DEFINE_INLINE_VIRTUAL_TRACE() { ContextLifecycleObserver::Trace(visitor); }
 };
 
+Document* Document::Create(const Document& document) {
+  Document* new_document = new Document(
+      DocumentInit::FromContext(const_cast<Document*>(&document), BlankURL()));
+  new_document->SetSecurityOrigin(document.GetSecurityOrigin());
+  new_document->SetContextFeatures(document.GetContextFeatures());
+  return new_document;
+}
+
 Document::Document(const DocumentInit& initializer,
                    DocumentClassFlags document_classes)
     : ContainerNode(0, kCreateDocument),
       TreeScope(*this),
       has_nodes_with_placeholder_style_(false),
       evaluate_media_queries_on_style_recalc_(false),
       pending_sheet_layout_(kNoLayoutWithPendingSheets),
       frame_(initializer.GetFrame()),
       // TODO(dcheng): Why does this need both a LocalFrame and LocalDOMWindow
       // pointer?
@@ skipping 6310 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (blink::Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->Url().GetString().Utf8().data());
 }
 #endif