Add a stack of queues of elements with reaction queues.

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

Index: third_party/WebKit/Source/core/dom/custom/CustomElementTestHelpers.h
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElementTestHelpers.h b/third_party/WebKit/Source/core/dom/custom/CustomElementTestHelpers.h
new file mode 100644
index 0000000000000000000000000000000000000000..5d4f1dc11113fd71f3d36f6e993427adb1c198ab
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+++ b/third_party/WebKit/Source/core/dom/custom/CustomElementTestHelpers.h
@@ -0,0 +1,78 @@
+// 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 CustomElementTestHelpers_h
+#define CustomElementTestHelpers_h
+
+#include "bindings/core/v8/ExceptionState.h"
+#include "core/dom/Document.h"
+#include "core/dom/Element.h"
+#include "core/dom/QualifiedName.h"
+#include "core/html/HTMLDocument.h"
+#include "platform/heap/Handle.h"
+#include "wtf/text/AtomicString.h"
+
+#include <utility>
+#include <vector>
+
+namespace blink {
+
+class CreateElement {
+    STACK_ALLOCATED()
+public:
+    CreateElement(const AtomicString& localName)
+        : m_namespaceURI(HTMLNames::xhtmlNamespaceURI)
+        , m_localName(localName)
+    {
+    }
+
+    CreateElement& inDocument(Document* document)
+    {
+        m_document = document;
+        return *this;
+    }
+
+    CreateElement& inNamespace(const AtomicString& uri)
+    {
+        m_namespaceURI = uri;
+        return *this;
+    }
+
+    CreateElement& withId(const AtomicString& id)
+    {
+        m_attributes.push_back(std::make_pair(HTMLNames::idAttr, id));
+        return *this;
+    }
+
+    CreateElement& withIsAttribute(const AtomicString& value)
+    {
+        m_attributes.push_back(std::make_pair(HTMLNames::isAttr, value));
+        return *this;
+    }
+
+    operator Element*() const
+    {
+        Document* document = m_document.get();
+        if (!document)
+            document = HTMLDocument::create();
+        NonThrowableExceptionState noExceptions;
+        Element* element = document->createElementNS(
+            m_namespaceURI,
+            m_localName,
+            noExceptions);
+        for (const auto& attribute : m_attributes)
+            element->setAttribute(attribute.first, attribute.second);
+        return element;
+    }
+
+private:
+    Member<Document> m_document;
+    AtomicString m_namespaceURI;
+    AtomicString m_localName;
+    std::vector<std::pair<QualifiedName, AtomicString>> m_attributes;
+};
+
+} // namespace blink
+
+#endif // CustomElementTestHelpers_h