Add [CEReactions] IDL attributes for Custom Elements V1

third_party/WebKit/Source/core/dom/custom/CustomElement.h

Index: third_party/WebKit/Source/core/dom/custom/CustomElement.h
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElement.h b/third_party/WebKit/Source/core/dom/custom/CustomElement.h
index 92e8304a085cdc87b4e9156e272a8d4aeca1443c..d86f22d3e64861bbb31a5407aafe19722652e4e2 100644
--- a/third_party/WebKit/Source/core/dom/custom/CustomElement.h
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElement.h
@@ -14,8 +14,10 @@
 namespace blink {
 
 class Document;
+class Element;
 class HTMLElement;
 class QualifiedName;
+class CustomElementDefinition;
 class CustomElementRegistry;
 
 class CORE_EXPORT CustomElement {
@@ -53,6 +55,8 @@ public:
 
     static HTMLElement* createCustomElement(Document&, const AtomicString& localName, CreateElementFlags);
     static HTMLElement* createCustomElement(Document&, const QualifiedName&, CreateElementFlags);
+
+    static void enqueueUpgradeReaction(Element*, CustomElementDefinition*);
 };
 
 } // namespace blink