ext.uls.eventlogger: Use mw.track() and remove EventLogging dep

Given the code no longer uses any EventLogging methods directly,
but rather mw.track(), this means it also doesn't need to declare
any dependencies, including for older MediaWiki versions this
will work as-is.

Change-Id: I8cdcef54321d0887c509fc3683acf132c113e628

resources/js/ext.uls.eventlogger.js

@@ -25,22 +25,22 @@
 ( function () {
 	'use strict';
 
-	var eventDefault = {
-		version: 1,
-		token: mw.user.id(),
-		contentLanguage: mw.config.get( 'wgContentLanguage' ),
-		interfaceLanguage: mw.config.get( 'wgUserLanguage' )
-	};
-
 	/**
-	 * Local wrapper for 'mw.eventLog.logEvent'
+	 * Try to emit an EventLogging event with schema 'UniversalLanguageSelector'.
+	 *
+	 * If EventLogging is not installed, this simply does nothing.
 	 *
 	 * @param {Object} event Event action and optional fields
-	 * @return {jQuery.Promise} Promise object for the logging call
 	 */
 	function log( event ) {
-		event = $.extend( {}, eventDefault, event );
-		return mw.eventLog.logEvent( 'UniversalLanguageSelector', event );
+		event = $.extend( {
+			version: 1,
+			token: mw.user.id(),
+			contentLanguage: mw.config.get( 'wgContentLanguage' ),
+			interfaceLanguage: mw.config.get( 'wgUserLanguage' )
+		}, event );
+
+		mw.track( 'event.UniversalLanguageSelector', event );
 	}
 
 	/**