[promisehook] Implement PromiseHook

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 8979a7b479312fe0797c5bfefcc1015029f44750..8bb9fc3784985eba593e97a703bb448f8118966f 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -2151,7 +2151,7 @@ Isolate::Isolate(bool enable_serializer)
       serializer_enabled_(enable_serializer),
       has_fatal_error_(false),
       initialized_from_snapshot_(false),
-      is_promisehook_enabled_(false),
+      promise_hook_(NULL),
       is_tail_call_elimination_enabled_(true),
       is_isolate_in_background_(false),
       cpu_profiler_(NULL),
@@ -3168,9 +3168,15 @@ void Isolate::FireCallCompletedCallback() {
   }
 }
 
-void Isolate::EnablePromiseHook() { is_promisehook_enabled_ = true; }
+void Isolate::SetPromiseHook(PromiseHook hook) { promise_hook_ = hook; }
 
-void Isolate::DisablePromiseHook() { is_promisehook_enabled_ = false; }
+void Isolate::RunPromiseHook(PromiseHookType type, Handle<JSPromise> promise,
+                             Handle<Object> parent) {
+  if (promise_hook_ == NULL) return;

[adamk, 2016/12/15 15:43:58]

Please at least use nullptr here, even if you use NULL in the initializer list
for consistency.

[gsathya, 2016/12/15 16:32:06]

Done.

+  PromiseHook hook = promise_hook_;

[adamk, 2016/12/15 15:43:58]

No need for this local.

[gsathya, 2016/12/15 16:32:06]

Done.

+  HandleScope scope(this);
+  hook(type, v8::Utils::PromiseToLocal(promise), v8::Utils::ToLocal(parent));
+}
 
 void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
   promise_reject_callback_ = callback;