Upgrade in-document custom elements when an element is defined.

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

Index: third_party/WebKit/Source/core/dom/custom/CustomElementUpgradeReaction.h
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElementUpgradeReaction.h b/third_party/WebKit/Source/core/dom/custom/CustomElementUpgradeReaction.h
new file mode 100644
index 0000000000000000000000000000000000000000..407cb66879b6e4974ee141bb7c0786fa50556fbd
--- /dev/null
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElementUpgradeReaction.h
@@ -0,0 +1,33 @@
+// 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 CustomElementUpgradeReaction_h
+#define CustomElementUpgradeReaction_h
+
+#include "core/CoreExport.h"
+#include "core/dom/custom/CustomElementReaction.h"
+#include "platform/heap/Handle.h"
+#include "wtf/Noncopyable.h"
+
+namespace blink {
+
+class CustomElementDefinition;
+class Element;
+
+class CORE_EXPORT CustomElementUpgradeReaction final
+    : public CustomElementReaction {
+    WTF_MAKE_NONCOPYABLE(CustomElementUpgradeReaction);
+public:
+    CustomElementUpgradeReaction(CustomElementDefinition*);
+    ~CustomElementUpgradeReaction() override;
+    DECLARE_VIRTUAL_TRACE();
+private:
+    void invoke(Element*) override;
+
+    Member<CustomElementDefinition> m_definition;
+};
+
+} // namespace blink
+
+#endif // CustomElementUpgradeReaction_h