Make PromiseRejectCallback fire after end-of-turn.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index f70d0e0e3dc418fc97a886ee9f8a59001cee7de2..76a11607a6779679cb18d9e04d8eef778023034d 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -5985,16 +5985,6 @@ Local<Promise> Promise::Then(Handle<Function> handler) {
 }
 
 
-bool Promise::HasHandler() {
-  i::Handle<i::JSObject> promise = Utils::OpenHandle(this);
-  i::Isolate* isolate = promise->GetIsolate();
-  LOG_API(isolate, "Promise::HasRejectHandler");
-  ENTER_V8(isolate);
-  i::Handle<i::Symbol> key = isolate->factory()->promise_has_handler_symbol();
-  return i::JSObject::GetDataProperty(promise, key)->IsTrue();
-}
-
-
 bool v8::ArrayBuffer::IsExternal() const {
   return Utils::OpenHandle(this)->is_external();
 }