Initial support for webfonts in MobileFrontend

Written in pair-programming with Ryan Kaldari.

This adds a version of webfonts initialization that is stripped
of any smart features. It only loads the basic jquery.webfonts
library and the fonts repository in a way that is usable
with the MobileFronted extension.

It is completely disabled by default.

It can be enabled by setting
$wgULSMobileWebfontsEnabled = true;
and even then it will only be enabled for users
who opted in for the mobile beta mode.

Change-Id: I488e411232a1192bbf46ae5675c701366bda9a3e

resources/js/ext.uls.webfonts.mobile.js

@@ -0,0 +1,49 @@
+/**
+ * MobileFrontend compatible ULS-Webfonts integration
+ *
+ * Copyright (C) 2013 Alolita Sharma, Amir Aharoni, Arun Ganesh, Brandon Harris,
+ * Niklas Laxström, Pau Giner, Ryan Kaldari, Santhosh Thottingal, Siebrand Mazeland
+ * and other contributors. See CREDITS for a list.
+ *
+ * UniversalLanguageSelector is dual licensed GPLv2 or later and MIT. You don't
+ * have to do anything special to choose one license or the other and you don't
+ * have to notify anyone which license you are using. You are free to use
+ * UniversalLanguageSelector in commercial projects as long as the copyright
+ * header is left intact. See files GPL-LICENSE and MIT-LICENSE for details.
+ *
+ * @file
+ * @ingroup Extensions
+ * @licence GNU General Public Licence 2.0 or later
+ * @licence MIT License
+ */
+( function ( $, mw ) {
+	'use strict';
+
+	var mediawikiFontRepository;
+
+	mw.webfonts = mw.webfonts || {};
+
+	mediawikiFontRepository = $.webfonts.repository;
+	mediawikiFontRepository.base = mw.config.get( 'wgExtensionAssetsPath' ) +
+		'/UniversalLanguageSelector/data/fontrepo/fonts/';
+
+	$( document ).ready( function () {
+		// MediaWiki specific overrides for jquery.webfonts
+		$.extend( $.fn.webfonts.defaults, {
+			repository: mediawikiFontRepository,
+			fontStack: $( 'body' ).css( 'font-family' ).split( /, /g ),
+			fontSelector: function ( repository, language ) {
+				var font = repository.defaultFont( language );
+
+				if ( font === 'system' ) {
+					// Avoid setting 'system' as a font in css
+					font = null;
+				}
+
+				return font;
+			}
+		} );
+
+		$( 'body' ).webfonts();
+	} );
+}( jQuery, mediaWiki ) );