Add the CustomElementsRegistry interface behind the flag

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DOMWindow_h
 #define DOMWindow_h
 
 #include "core/CoreExport.h"
 #include "core/events/EventTarget.h"
 #include "core/frame/DOMWindowBase64.h"
 #include "core/frame/Location.h"
 #include "platform/heap/Handle.h"
 #include "platform/scroll/ScrollableArea.h"
 
 #include "wtf/Forward.h"
 
 namespace blink {
 
 class ApplicationCache;
 class BarProp;
 class CSSRuleList;
 class CSSStyleDeclaration;
 class Console;
+class CustomElementsRegistry;
 class DOMSelection;
 class DOMWindowCSS;
 class Document;
 class Element;
 class Frame;
 class FrameRequestCallback;
 class History;
 class IdleRequestCallback;
 class IdleRequestOptions;
 class LocalDOMWindow;
@@ skipping 133 matching lines @@
 
     // WebKit animation extensions
     virtual int requestAnimationFrame(FrameRequestCallback*) = 0;
     virtual int webkitRequestAnimationFrame(FrameRequestCallback*) = 0;
     virtual void cancelAnimationFrame(int id) = 0;
 
     // Idle callback extensions
     virtual int requestIdleCallback(IdleRequestCallback*, const IdleRequestOptions&) = 0;
     virtual void cancelIdleCallback(int id) = 0;
 
+    // Custom elements
+    virtual CustomElementsRegistry* customElements() const = 0;
+
     void captureEvents() { }
     void releaseEvents() { }
 
     // FIXME: This handles both window[index] and window.frames[index]. However,
     // the spec exposes window.frames[index] across origins but not
     // window[index]...
     DOMWindow* anonymousIndexedGetter(uint32_t) const;
 
     void postMessage(PassRefPtr<SerializedScriptValue> message, const MessagePortArray*, const String& targetOrigin, LocalDOMWindow* source, ExceptionState&);
 
@@ skipping 36 matching lines @@
     // implementation details to scripts.
     bool m_windowIsClosing;
 
 private:
     mutable Member<Location> m_location;
 };
 
 } // namespace blink
 
 #endif // DOMWindow_h