Clean up.

src/core/EventDispatcher.js

@@ -68,9 +68,9 @@ Object.assign( EventDispatcher.prototype, {
 
 			event.target = this;
 
-			var array = listenerArray.slice(0);
+			var array = listenerArray.slice( 0 );
 
-			for (var i = 0, length = array.length; i < length; i ++ ) {
+			for ( var i = 0, l = array.length; i < l; i ++ ) {
 
 				array[ i ].call( this, event );