Add a scoped context object for synchronous CE creation

third_party/WebKit/Source/core/frame/LocalDOMWindow.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 193 matching lines @@
     void documentWasClosed();
     void statePopped(PassRefPtr<SerializedScriptValue>);
 
     // FIXME: This shouldn't be public once LocalDOMWindow becomes ExecutionContext.
     void clearEventQueue();
 
     void acceptLanguagesChanged();
 
     FloatSize getViewportSize(IncludeScrollbarsInRect) const;
 
+    void setCustomElementCreationContext(Document*);
+    Document* customElementCreationContext() const;
+
 protected:
     // EventTarget overrides.
     void addedEventListener(const AtomicString& eventType, RegisteredEventListener&) override;
     void removedEventListener(const AtomicString& eventType, const RegisteredEventListener&) override;
 
     // Protected DOMWindow overrides.
     void schedulePostMessage(MessageEvent*, PassRefPtr<SecurityOrigin> target, Document* source) override;
 
 private:
     class WindowFrameObserver;
@@ skipping 36 matching lines @@
     String m_status;
     String m_defaultStatus;
 
     mutable Member<ApplicationCache> m_applicationCache;
 
     Member<DOMWindowEventQueue> m_eventQueue;
     RefPtr<SerializedScriptValue> m_pendingStateObject;
 
     HeapHashSet<Member<PostMessageTimer>> m_postMessageTimers;
     HeapHashSet<WeakMember<EventListenerObserver>> m_eventListenerObservers;
+
+    Member<Document> m_customElementCreationContext = nullptr;
 };
 
 DEFINE_TYPE_CASTS(LocalDOMWindow, DOMWindow, x, x->isLocalDOMWindow(), x.isLocalDOMWindow());
 
 inline String LocalDOMWindow::status() const
 {
     return m_status;
 }
 
 inline String LocalDOMWindow::defaultStatus() const
 {
     return m_defaultStatus;
 }
 
 } // namespace blink
 
 #endif // LocalDOMWindow_h