Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibHTML/CSS/StyleResolver.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <AK/OwnPtr.h>
+#include <AK/NonnullRefPtrVector.h>
+
+class Document;
+class Element;
+class ParentNode;
+class StyleRule;
+class StyleSheet;
+class StyledNode;
+
+class StyleResolver {
+public:
+    explicit StyleResolver(Document&);
+    ~StyleResolver();
+
+    Document& document() { return m_document; }
+    const Document& document() const { return m_document; }
+
+    NonnullRefPtr<StyledNode> create_styled_node(const Element&);
+    NonnullRefPtr<StyledNode> create_styled_node(const Document&);
+
+    NonnullRefPtrVector<StyleRule> collect_matching_rules(const Element&) const;
+
+
+private:
+    Document& m_document;
+};