Introduce HTMLDataListOptionsCollection subclass for HTMLCollection

Source/core/html/HTMLDataListOptionsCollection.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 HTMLDataListOptionsCollection_h
+#define HTMLDataListOptionsCollection_h
+
+#include "core/html/HTMLCollection.h"
+#include "core/html/HTMLOptionElement.h"
+
+namespace blink {
+
+class HTMLDataListOptionsCollection : public HTMLCollection {
+public:
+    static PassRefPtrWillBeRawPtr<HTMLDataListOptionsCollection> create(ContainerNode& ownerNode, CollectionType type)
+    {
+        ASSERT_UNUSED(type, type == DataListOptions);
+        return adoptRefWillBeNoop(new HTMLDataListOptionsCollection(ownerNode));
+    }
+
+    HTMLOptionElement* item(unsigned offset) const { return toHTMLOptionElement(HTMLCollection::item(offset)); }
+
+    bool elementMatches(const HTMLElement&) const;
+private:
+    explicit HTMLDataListOptionsCollection(ContainerNode& ownerNode)
+        : HTMLCollection(ownerNode, DataListOptions, DoesNotOverrideItemAfter)
+    { }
+};
+
+DEFINE_TYPE_CASTS(HTMLDataListOptionsCollection, LiveNodeListBase, collection, collection->type() == DataListOptions, collection.type() == DataListOptions);
+
+inline bool HTMLDataListOptionsCollection::elementMatches(const HTMLElement& element) const
+{
+    if (isHTMLOptionElement(element)) {
+        const HTMLOptionElement& option = toHTMLOptionElement(element);
+        if (!option.isDisabledFormControl() && !option.value().isEmpty())
+            return true;
+    }
+    return false;
+}
+
+} // namespace blink
+
+#endif // HTMLDataListOptionsCollection_h