[es6] Align Promise.resolve with the spec

* Promise.resolve is now works with subclasses
* Spec removed [[PromiseConstructor]] now can simply use constructor
* Promise.resolve ignores species

R=littledan@chromium.org,domenic@chromium.org
BUG=v8:4161,v8:4341
LOG=Y

Review URL: https://codereview.chromium.org/1362773002

Cr-Commit-Position: refs/heads/master@{#31116}

src/promise.js

@@ -285,8 +285,11 @@ function PromiseThen(onResolve, onReject) {
 // Combinators.
 
 function PromiseCast(x) {
-  // TODO(rossberg): cannot do better until we support @@create.
-  return IsPromise(x) ? x : new this(function(resolve) { resolve(x) });
+  if (IsPromise(x) && x.constructor === this) {
+    return x;
+  } else {
+    return new this(function(resolve) { resolve(x) });
+  }
 }
 
 function PromiseAll(iterable) {

test/mjsunit/es6/promises.js

@@ -1011,9 +1011,9 @@ function assertAsyncDone(iteration) {
   log = ""
   var p4 = MyPromise.resolve(4)
   var p5 = MyPromise.reject(5)
-  assertTrue(p4 instanceof Promise, "subclass/instance4")
+  assertTrue(p4 instanceof MyPromise, "subclass/instance4")
   assertTrue(p4 instanceof MyPromise, "subclass/instance-my4")
-  assertTrue(p5 instanceof Promise, "subclass/instance5")
+  assertTrue(p5 instanceof MyPromise, "subclass/instance5")
   assertTrue(p5 instanceof MyPromise, "subclass/instance-my5")
   d3.resolve(3)
   assertTrue(log === "nx4nr5x3", "subclass/resolve")
@@ -1028,12 +1028,35 @@ function assertAsyncDone(iteration) {
 
   log = ""
   Promise.all([11, Promise.accept(12), 13, MyPromise.accept(14), 15, 16])
-  assertTrue(log === "nx14n", "subclass/all/arg")
+
+  assertTrue(log === "nx14", "subclass/all/arg")
 
   log = ""
   MyPromise.all([21, Promise.accept(22), 23, MyPromise.accept(24), 25, 26])
-  assertTrue(log === "nx24nnx21nnx23nnnx25nnx26n", "subclass/all/self")
+  assertTrue(log === "nx24nnx21nnnnx23nnnx25nnx26n", "subclass/all/self")
 })();
 
+(function() {
+  'use strict';
+
+  class Pact extends Promise { }
+  class Vow  extends Pact    { }
+  class Oath extends Vow     { }
+
+  Oath.constructor = Vow;
+
+  assertTrue(Pact.resolve(Pact.resolve()).constructor === Pact,
+             "subclass/resolve/own");
+
+  assertTrue(Pact.resolve(Promise.resolve()).constructor === Pact,
+             "subclass/resolve/ancestor");
+
+  assertTrue(Pact.resolve(Vow.resolve()).constructor === Pact,
+             "subclass/resolve/descendant"); var vow = Vow.resolve();
+
+  vow.constructor = Oath;
+  assertTrue(Oath.resolve(vow) === vow,
+             "subclass/resolve/descendant with transplanted own constructor");
+}());
 
 assertAsyncDone()

test/test262/test262.status

@@ -288,9 +288,6 @@
   'built-ins/Promise/race/S25.4.4.3_A3.1_T2': [FAIL],
   'built-ins/Promise/reject/S25.4.4.4_A3.1_T1': [FAIL],
 
-  # https://code.google.com/p/v8/issues/detail?id=4341
-  'built-ins/Promise/resolve/arg-uniq-ctor': [FAIL],
-
   # https://code.google.com/p/v8/issues/detail?id=4119
   'built-ins/RegExp/15.10.4.1-1': [FAIL],
   'built-ins/RegExp/S15.10.3.1_A2_T1': [FAIL],