Implement ScriptPromise and ScriptFunction

LayoutTests/fast/js/Promise-native-then.html

Index: LayoutTests/fast/js/Promise-native-then.html
diff --git a/LayoutTests/fast/js/Promise-then-without-callbacks.html b/LayoutTests/fast/js/Promise-native-then.html
similarity index 50%
copy from LayoutTests/fast/js/Promise-then-without-callbacks.html
copy to LayoutTests/fast/js/Promise-native-then.html
index ccf7854e287570fae4971ebb3bb035a15d6d9bf4..e556b0d71ab882fa8bfa1fa35ca5a53815786166 100644
--- a/LayoutTests/fast/js/Promise-then-without-callbacks.html
+++ b/LayoutTests/fast/js/Promise-native-then.html
@@ -11,12 +11,13 @@ description('Test Promise.');
 
 window.jsTestIsAsync = true;
 
-new Promise(function(r) { r.fulfill('hello'); })
-  .then()
-  .then(function(result) {
-    window.result = result;
-    shouldBeEqualToString('result', 'hello');
-    finishJSTest();
+  var promise = new Promise(function(r) { r.fulfill(10); });
+  var newPromise = window.internals.addOneToPromise(promise);
+  console.log("Got a new promise: " + newPromise);
+  newPromise.then(function(presult) {
+      result = presult;
+      shouldBe('result', '11');
+      finishJSTest();
   });
 
 </script>