Remove --promise-extra flag

test/mjsunit/es6/debug-promises/reject-uncaught-all.js

Index: test/mjsunit/es6/debug-promises/reject-uncaught-all.js
diff --git a/test/mjsunit/es6/debug-promises/reject-uncaught-all.js b/test/mjsunit/es6/debug-promises/reject-uncaught-all.js
index 63e3b8678d82e4ff893593e9aa589b8a75c597d8..0c5ecc5f3a3ead618e3500e3d9539a260b06e725 100644
--- a/test/mjsunit/es6/debug-promises/reject-uncaught-all.js
+++ b/test/mjsunit/es6/debug-promises/reject-uncaught-all.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug --allow-natives-syntax --promise-extra
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when we listen to all exceptions and
 // there is a catch handler for the to-be-rejected Promise.
@@ -18,7 +18,7 @@ var p = new Promise(function(resolve, reject) {
   resolve();
 });
 
-var q = p.chain(
+var q = p.then(
   function() {
     log.push("reject");
     return Promise.reject(new Error("uncaught reject"));