Recursively defining custom elements should not lead to redefinition

third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h

 // Copyright 2016 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 V8PrivateProperty_h
 #define V8PrivateProperty_h
 
 #include "bindings/core/v8/ScopedPersistent.h"
 #include "bindings/core/v8/ScriptPromiseProperties.h"
 #include "bindings/core/v8/V8BindingMacros.h"
 #include "bindings/core/v8/V8PerIsolateData.h"
 #include "core/CoreExport.h"
 #include "wtf/Allocator.h"
 #include "wtf/PtrUtil.h"
 #include <memory>
 #include <v8.h>
 
 namespace blink {
 
 class ScriptState;
 class ScriptWrappable;
 
 // Apply |X| for each pair of (InterfaceName, PrivateKeyName).
 #define V8_PRIVATE_PROPERTY_FOR_EACH(X) \
+    X(CustomElementsRegistry, ConstructorsBeingDefined) \
     X(MessageEvent, CachedData) \
     X(PrivateScriptRunner, IsInitialized) \
     X(IntersectionObserver, Callback) \
     X(MutationObserver, Callback) \
     X(PerformanceObserver, Callback)
 
 // The getter's name for a private property.
 #define V8_PRIVATE_PROPERTY_GETTER_NAME(InterfaceName, PrivateKeyName) \
     get##InterfaceName##PrivateKeyName
 
@@ skipping 100 matching lines @@
 
 #define V8_PRIVATE_PROPERTY_DECLARE_MEMBER(InterfaceName, KeyName) \
     ScopedPersistent<v8::Private> V8_PRIVATE_PROPERTY_MEMBER_NAME(InterfaceName, KeyName); // NOLINT(readability/naming/underscores)
     V8_PRIVATE_PROPERTY_FOR_EACH(V8_PRIVATE_PROPERTY_DECLARE_MEMBER)
 #undef V8_PRIVATE_PROPERTY_DECLARE_MEMBER
 };
 
 } // namespace blink
 
 #endif // V8PrivateProperty_h