Remove --promise-extra flag

src/api.cc

 // Copyright 2012 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.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 6689 matching lines @@
   return Just(true);
 }
 
 
 void Promise::Resolver::Reject(Local<Value> value) {
   auto context = ContextFromHeapObject(Utils::OpenHandle(this));
   USE(Reject(context, value));
 }
 
 
-namespace {
-
-MaybeLocal<Promise> DoChain(Value* value, Local<Context> context,
-                            Local<Function> handler) {
-  PREPARE_FOR_EXECUTION(context, Promise, Chain, Promise);
-  auto self = Utils::OpenHandle(value);
-  i::Handle<i::Object> argv[] = {Utils::OpenHandle(*handler)};
-  i::Handle<i::Object> result;
-  has_pending_exception = !i::Execution::Call(isolate, isolate->promise_chain(),
-                                              self, arraysize(argv), argv)
-                               .ToHandle(&result);
-  RETURN_ON_FAILED_EXECUTION(Promise);
-  RETURN_ESCAPED(Local<Promise>::Cast(Utils::ToLocal(result)));
-}
-
-}  // namespace
-
-
-MaybeLocal<Promise> Promise::Chain(Local<Context> context,
-                                   Local<Function> handler) {
-  return DoChain(this, context, handler);
-}
-
-
-Local<Promise> Promise::Chain(Local<Function> handler) {
-  auto context = ContextFromHeapObject(Utils::OpenHandle(this));
-  RETURN_TO_LOCAL_UNCHECKED(DoChain(this, context, handler), Promise);
-}
-
-
 MaybeLocal<Promise> Promise::Catch(Local<Context> context,
                                    Local<Function> handler) {
   PREPARE_FOR_EXECUTION(context, Promise, Catch, Promise);
   auto self = Utils::OpenHandle(this);
   i::Handle<i::Object> argv[] = { Utils::OpenHandle(*handler) };
   i::Handle<i::Object> result;
   has_pending_exception = !i::Execution::Call(isolate, isolate->promise_catch(),
                                               self, arraysize(argv), argv)
                                .ToHandle(&result);
   RETURN_ON_FAILED_EXECUTION(Promise);
@@ skipping 2268 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8