LibWeb: Add the History object and stub pushState and replaceState

The spec allows us to optionally return from these for any reason.
Our reason is that we don't have all the infrastructure in place yet to
implement them.

Userland/Libraries/LibWeb/HTML/History.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2021, Luke Wilde <lukew@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/RefCounted.h>
+#include <AK/Weakable.h>
+#include <LibJS/Heap/Handle.h>
+#include <LibWeb/Bindings/Wrappable.h>
+#include <LibWeb/DOM/ExceptionOr.h>
+#include <LibWeb/Forward.h>
+
+namespace Web::HTML {
+
+class History final
+    : public RefCounted<History>
+    , public Weakable<History>
+    , public Bindings::Wrappable {
+public:
+    using WrapperType = Bindings::HistoryWrapper;
+
+    static NonnullRefPtr<History> create(DOM::Document& document)
+    {
+        return adopt_ref(*new History(document));
+    }
+
+    virtual ~History() override;
+
+    DOM::ExceptionOr<void> push_state(JS::Value data, String const& unused, String const& url);
+    DOM::ExceptionOr<void> replace_state(JS::Value data, String const& unused, String const& url);
+
+private:
+    explicit History(DOM::Document&);
+
+    enum class IsPush {
+        No,
+        Yes,
+    };
+    DOM::ExceptionOr<void> shared_history_push_replace_state(JS::Value data, String const& url, IsPush is_push);
+
+    DOM::Document& m_associated_document;
+};
+
+}