Remove --promise-extra flag

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

Index: test/mjsunit/es6/debug-promises/reject-caught-all.js
diff --git a/test/mjsunit/es6/debug-promises/reject-caught-all.js b/test/mjsunit/es6/debug-promises/reject-caught-all.js
index e1a653889d0238ec5ccd070828b9d754d1dd7087..8d348ce6b6896d41746c7b486479bfac7f61e610 100644
--- a/test/mjsunit/es6/debug-promises/reject-caught-all.js
+++ b/test/mjsunit/es6/debug-promises/reject-caught-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(value) {
     log.push("reject");
     return Promise.reject(new Error("reject"));