Merge pull request #11479 from 06wj/patch-event

Optimize EventDispatcher.dispatchEvent

src/core/EventDispatcher.js

@@ -68,16 +68,9 @@ Object.assign( EventDispatcher.prototype, {
 
 			event.target = this;
 
-			var array = [], i = 0;
-			var length = listenerArray.length;
+			var array = listenerArray.slice(0);
 
-			for ( i = 0; i < length; i ++ ) {
-
-				array[ i ] = listenerArray[ i ];
-
-			}
-
-			for ( i = 0; i < length; i ++ ) {
+			for (var i = 0, length = array.length; i < length; i ++ ) {
 
 				array[ i ].call( this, event );