MDL-55224 core: Import PHP-CSS-Parser into core

Part of MDL-55071

lib/php-css-parser/Settings.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace Sabberworm\CSS;
+
+use Sabberworm\CSS\Rule\Rule;
+
+/**
+ * Parser settings class.
+ *
+ * Configure parser behaviour here.
+ */
+class Settings {
+	/**
+	* Multi-byte string support. If true (mbstring extension must be enabled), will use (slower) mb_strlen, mb_convert_case, mb_substr and mb_strpos functions. Otherwise, the normal (ASCII-Only) functions will be used.
+	*/
+	public $bMultibyteSupport;
+
+	/**
+	* The default charset for the CSS if no `@charset` rule is found. Defaults to utf-8.
+	*/
+	public $sDefaultCharset = 'utf-8';
+
+	/**
+	* Lenient parsing. When used (which is true by default), the parser will not choke on unexpected tokens but simply ignore them.
+	*/
+	public $bLenientParsing = true;
+
+	private function __construct() {
+		$this->bMultibyteSupport = extension_loaded('mbstring');
+	}
+
+	public static function create() {
+		return new Settings();
+	}
+	
+	public function withMultibyteSupport($bMultibyteSupport = true) {
+		$this->bMultibyteSupport = $bMultibyteSupport;
+		return $this;
+	}
+	
+	public function withDefaultCharset($sDefaultCharset) {
+		$this->sDefaultCharset = $sDefaultCharset;
+		return $this;
+	}
+	
+	public function withLenientParsing($bLenientParsing = true) {
+		$this->bLenientParsing = $bLenientParsing;
+		return $this;
+	}
+	
+	public function beStrict() {
+		return $this->withLenientParsing(false);
+	}
+}