Revert "PromiseThen should ignore non-function parameters."

test/mjsunit/es6/promises.js

Index: test/mjsunit/es6/promises.js
diff --git a/test/mjsunit/es6/promises.js b/test/mjsunit/es6/promises.js
index 8575ba15ea885c4f7f1bb58c87409d772d6ccb98..ba5a306f84a23ecee98f11ddb1b1991afd394f1e 100644
--- a/test/mjsunit/es6/promises.js
+++ b/test/mjsunit/es6/promises.js
@@ -399,30 +399,6 @@ function assertAsyncDone(iteration) {
 (function() {
   var deferred = Promise.defer()
   var p1 = deferred.promise
-  var p2 = p1.then(1, 2)
-  p2.then(
-    function(x) { assertAsync(x === 5, "then/resolve-non-function") },
-    assertUnreachable
-  )
-  deferred.resolve(5)
-  assertAsyncRan()
-})();
-
-(function() {
-  var deferred = Promise.defer()
-  var p1 = deferred.promise
-  var p2 = p1.then(1, 2)
-  p2.then(
-    assertUnreachable,
-    function(x) { assertAsync(x === 5, "then/reject-non-function") }
-  )
-  deferred.reject(5)
-  assertAsyncRan()
-})();
-
-(function() {
-  var deferred = Promise.defer()
-  var p1 = deferred.promise
   var p2 = {then: function(onResolve, onReject) { onResolve(p1) }}
   var p3 = Promise.accept(p2)
   p3.chain(