Remove --promise-extra flag

test/mjsunit/es6/debug-promises/reject-with-throw-in-reject.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // 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 a Promise is rejected, which is caught by a
 // custom promise, which throws a new exception in its reject handler.
 // We expect two Exception debug events:
 //  1) when promise q is rejected.
 //  2) when the custom reject closure in MyPromise throws an exception.
 
 Debug = debug.Debug;
 
 var expected_events = 1;
@@ skipping 10 matching lines @@
     throw new Error("reject");  // event
   };
   var resolve = function() { };
   log.push("construct");
   resolver(resolve, reject);
 };
 
 MyPromise.prototype = new Promise(function() {});
 p.constructor = MyPromise;
 
-var q = p.chain(
+var q = p.then(
   function() {
     log.push("reject caught");
     return Promise.reject(new Error("caught"));
   });
 
 function listener(event, exec_state, event_data, data) {
   try {
     if (event == Debug.DebugEvent.Exception) {
       expected_events--;
       assertTrue(expected_events >= 0);
@@ skipping 28 matching lines @@
       }
     } catch (e) {
       %AbortJS(e + "\n" + e.stack);
     }
   }
 
   %EnqueueMicrotask(checkResult);
 }
 
 testDone(0);