Remove --promise-extra flag

test/mjsunit/es6/debug-promises/reject-caught-late.js

Index: test/mjsunit/es6/debug-promises/reject-caught-late.js
diff --git a/test/mjsunit/es6/debug-promises/reject-caught-late.js b/test/mjsunit/es6/debug-promises/reject-caught-late.js
index 922449261b7e864aa25c1b25a687801b954ed860..44eb76728fe7c65256c8819f2b483fa711e9b0a5 100644
--- a/test/mjsunit/es6/debug-promises/reject-caught-late.js
+++ b/test/mjsunit/es6/debug-promises/reject-caught-late.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 only listen to uncaught exceptions, the Promise
 // is rejected, and a catch handler is installed right before the rejection.
@@ -14,7 +14,7 @@ var p = new Promise(function(resolve, reject) {
   resolve();
 });
 
-var q = p.chain(
+var q = p.then(
   function() {
     q.catch(function(e) {
       assertEquals("caught", e.message);