All documents should have a RegistrationContext.

sky/engine/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.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 249 matching lines @@
     , m_renderView(0)
 #if !ENABLE(OILPAN)
     , m_weakFactory(this)
 #endif
     , m_contextDocument(initializer.contextDocument())
     , m_loadEventDelayCount(0)
     , m_loadEventDelayTimer(this, &Document::loadEventDelayTimerFired)
     , m_didSetReferrerPolicy(false)
     , m_referrerPolicy(ReferrerPolicyDefault)
     , m_directionSetOnDocumentElement(false)
-    , m_registrationContext(initializer.registrationContext(this))
+    , m_registrationContext(initializer.registrationContext())
     , m_elementDataCacheClearTimer(this, &Document::elementDataCacheClearTimerFired)
     , m_timeline(AnimationTimeline::create(this))
     , m_templateDocumentHost(nullptr)
     , m_hasViewportUnits(false)
     , m_styleRecalcElementCounter(0)
 {
     setClient(this);
 
+    if (!m_registrationContext)
+        m_registrationContext = CustomElementRegistrationContext::create();
+
     m_fetcher = ResourceFetcher::create(this);
 
     // We depend on the url getting immediately set in subframes, but we
     // also depend on the url NOT getting immediately set in opened windows.
     // See fast/dom/early-frame-url.html
     // and fast/dom/location-new-window-no-crash.html, respectively.
     // FIXME: Can/should we unify this behavior?
     if (initializer.shouldSetURL())
         setURL(initializer.url());
 
@@ skipping 154 matching lines @@
     return Element::create(QualifiedName(name), this);
 }
 
 ScriptValue Document::registerElement(ScriptState* scriptState, const AtomicString& name, ExceptionState& exceptionState)
 {
     return registerElement(scriptState, name, Dictionary(), exceptionState);
 }
 
 ScriptValue Document::registerElement(ScriptState* scriptState, const AtomicString& name, const Dictionary& options, ExceptionState& exceptionState)
 {
-    if (!registrationContext()) {
-        exceptionState.throwDOMException(NotSupportedError, "No element registration context is available.");
-        return ScriptValue();
-    }
-
     CustomElementConstructorBuilder constructorBuilder(scriptState, &options);
-    registrationContext()->registerElement(this, &constructorBuilder, name, exceptionState);
+    registrationContext().registerElement(this, &constructorBuilder, name, exceptionState);
     return constructorBuilder.bindingsReturnValue();
 }
 
 CustomElementMicrotaskRunQueue* Document::customElementMicrotaskRunQueue()
 {
     if (!m_customElementMicrotaskRunQueue)
         m_customElementMicrotaskRunQueue = CustomElementMicrotaskRunQueue::create();
     return m_customElementMicrotaskRunQueue.get();
 }
 
@@ skipping 2082 matching lines @@
 
 Document& Document::ensureTemplateDocument()
 {
     if (isTemplateDocument())
         return *this;
 
     if (m_templateDocument)
         return *m_templateDocument;
 
     if (isHTMLDocument()) {
-        DocumentInit init = DocumentInit::fromContext(contextDocument(), blankURL()).withNewRegistrationContext();
+        DocumentInit init = DocumentInit::fromContext(contextDocument(), blankURL());
         m_templateDocument = HTMLDocument::create(init);
     } else {
         m_templateDocument = Document::create(DocumentInit(blankURL()));
     }
 
     m_templateDocument->m_templateDocumentHost = this; // balanced in dtor.
 
     return *m_templateDocument.get();
 }
 
@@ skipping 67 matching lines @@
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (WeakDocumentSet::const_iterator it = set.begin(); it != set.end(); ++it) {
         fprintf(stderr, "- Document %p URL: %s\n", *it, (*it)->url().string().utf8().data());
     }
 }
 #endif