Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibWeb/HTML/HTMLBaseElement.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/HTML/HTMLElement.h>
+
+namespace Web::HTML {
+
+class HTMLBaseElement final : public HTMLElement {
+    WEB_PLATFORM_OBJECT(HTMLBaseElement, HTMLElement);
+    JS_DECLARE_ALLOCATOR(HTMLBaseElement);
+
+public:
+    virtual ~HTMLBaseElement() override;
+
+    String href() const;
+    WebIDL::ExceptionOr<void> set_href(String const& href);
+
+    URL::URL const& frozen_base_url() const { return m_frozen_base_url; }
+
+    virtual void inserted() override;
+    virtual void removed_from(Node*) override;
+    virtual void attribute_changed(FlyString const& name, Optional<String> const& old_value, Optional<String> const& value) override;
+
+private:
+    HTMLBaseElement(DOM::Document&, DOM::QualifiedName);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual bool is_html_base_element() const override { return true; }
+
+    // https://html.spec.whatwg.org/multipage/semantics.html#frozen-base-url
+    // A base element that is the first base element with an href content attribute in a document tree has a frozen base URL.
+    URL::URL m_frozen_base_url;
+
+    void set_the_frozen_base_url();
+};
+
+}
+
+namespace Web::DOM {
+template<>
+inline bool Node::fast_is<HTML::HTMLBaseElement>() const { return is_html_base_element(); }
+}