[Layout API] Create api/LayoutLIItem and use it in html/HTMLLIElement

third_party/WebKit/Source/core/layout/api/LayoutLIItem.h

Index: third_party/WebKit/Source/core/layout/api/LayoutLIItem.h
diff --git a/third_party/WebKit/Source/core/layout/api/LayoutLIItem.h b/third_party/WebKit/Source/core/layout/api/LayoutLIItem.h
new file mode 100644
index 0000000000000000000000000000000000000000..3bbce4ea38e0ec01a8b16bb888274d882604d49b
--- /dev/null
+++ b/third_party/WebKit/Source/core/layout/api/LayoutLIItem.h
@@ -0,0 +1,49 @@
+// 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 LayoutLIItem_h
+#define LayoutLIItem_h
+
+#include "core/layout/LayoutListItem.h"
+#include "core/layout/api/LayoutBoxItem.h"
+
+namespace blink {
+
+class LayoutLIItem : public LayoutBoxItem {
+public:
+    explicit LayoutLIItem(LayoutListItem* layoutListItem)
+        : LayoutBoxItem(layoutListItem)
+    {
+    }
+
+    explicit LayoutLIItem(const LayoutItem& item)
+        : LayoutBoxItem(item)
+    {
+        ASSERT(!item || item.isListItem());
+    }
+
+    explicit LayoutLIItem(std::nullptr_t) : LayoutBoxItem(nullptr) { }
+
+    LayoutLIItem() { }
+
+    void setNotInList(bool notInList)
+    {
+        return toListItem()->setNotInList(notInList);
+    }
+
+private:
+    LayoutListItem* toListItem()
+    {
+        return toLayoutListItem(layoutObject());
+    }
+
+    const LayoutListItem* toListItem() const
+    {
+        return toLayoutListItem(layoutObject());
+    }
+};
+
+} // namespace blink
+
+#endif // LayoutLIItem_h