chakrashim: revive object during ClearWeak

Typically a WeakCallback may call ClearWeak to revive the object. e.g.
chakrashim's ClearWeak is followed by JsAddRef. Change the clearing
code to optionally revive the object via setting a dummy
ObjectBeforeCollect callback.

Reviewed-by: curtisman

deps/chakrashim/include/v8.h

@@ -255,7 +255,7 @@ EXPORT void SetObjectWeakReferenceCallback(
     std::shared_ptr<WeakReferenceCallbackWrapper>* weakWrapper);
 // A helper method for turning off the WeakReferenceCallback that was set using
 // the previous method
-EXPORT void ClearObjectWeakReferenceCallback(JsValueRef object);
+EXPORT void ClearObjectWeakReferenceCallback(JsValueRef object, bool revive);
 
 EXPORT JsValueRef MarshalJsValueRefToContext(
   JsValueRef value, JsContextRef context);
@@ -1563,7 +1563,7 @@ void Persistent<T>::Dispose() {
   if (_ref != JS_INVALID_REFERENCE && !V8::IsDead()) {
     if (IsWeak()) {
       if (_weakWrapper.unique()) {
-        chakrashim::ClearObjectWeakReferenceCallback(_ref);
+        chakrashim::ClearObjectWeakReferenceCallback(_ref, /*revive*/false);
       }
       _weakWrapper.reset();
     } else {
@@ -1611,7 +1611,7 @@ template <class T>
 void Persistent<T>::ClearWeak() {
   if (_ref != JS_INVALID_REFERENCE && IsWeak()) {
     if (_weakWrapper.unique()) {
-      chakrashim::ClearObjectWeakReferenceCallback(_ref);
+      chakrashim::ClearObjectWeakReferenceCallback(_ref, /*revive*/true);
     }
     _weakWrapper.reset();
 

deps/chakrashim/src/v8persistent.cc

@@ -39,8 +39,14 @@ static void CALLBACK WeakReferenceCallbackWrapperCallback(
   callbackWrapper->callback(callbackData);
 }
 
-void ClearObjectWeakReferenceCallback(JsValueRef object) {
-  JsSetObjectBeforeCollectCallback(object, nullptr, nullptr);
+static void CALLBACK DummyObjectBeforeCollectCallback(
+  _In_ JsRef ref, _In_opt_ void *data) {
+  // Do nothing, only used to revive an object temporarily
+}
+
+void ClearObjectWeakReferenceCallback(JsValueRef object, bool revive) {
+  JsSetObjectBeforeCollectCallback(
+    object, nullptr, revive ? DummyObjectBeforeCollectCallback : nullptr);
 }
 
 void SetObjectWeakReferenceCallback(