LibWeb: Implement ChildNode.remove

Userland/Libraries/LibWeb/DOM/ChildNode.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2021, Luke Wilde <lukew@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+namespace Web::DOM {
+
+// https://dom.spec.whatwg.org/#childnode
+template<typename NodeType>
+class ChildNode {
+public:
+    // https://dom.spec.whatwg.org/#dom-childnode-remove
+    void remove_binding()
+    {
+        auto* node = static_cast<NodeType*>(this);
+
+        // 1. If this’s parent is null, then return.
+        if (!node->parent())
+            return;
+
+        // 2. Remove this.
+        node->remove();
+    }
+
+protected:
+    ChildNode() = default;
+};
+
+}