[runtime] Let native setters have a return value.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 9e8b06c6fc467e8ca7668d039df96b29a9f9c4eb..d299dc86065cb91a945a2d92e1d5e5b5215f8036 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -1417,12 +1417,20 @@ Maybe<bool> Object::SetPropertyWithAccessor(LookupIterator* it,
       return Nothing<bool>();
     }
 
-    v8::AccessorNameSetterCallback call_fun =
-        v8::ToCData<v8::AccessorNameSetterCallback>(info->setter());
-    // TODO(verwaest): We should not get here anymore once all AccessorInfos are
-    // marked as special_data_property. They cannot both be writable and not
-    // have a setter.
-    if (call_fun == nullptr) return Just(true);
+    // The actual type of call_fun is either v8::AccessorNameSetterCallback or
+    // i::Accesors::AccessorNameBooleanSetterCallback, depending on whether the
+    // AccessorInfo was created by the API or internally (see accessors.cc).
+    // Here we handle both cases using GenericNamedPropertySetterCallback and
+    // its Call method.
+    GenericNamedPropertySetterCallback call_fun =
+        v8::ToCData<GenericNamedPropertySetterCallback>(info->setter());
+
+    if (call_fun == nullptr) {
+      // TODO(verwaest): We should not get here anymore once all AccessorInfos
+      // are marked as special_data_property. They cannot both be writable and
+      // not have a setter.
+      return Just(true);
+    }
 
     if (info->is_sloppy() && !receiver->IsJSReceiver()) {
       ASSIGN_RETURN_ON_EXCEPTION_VALUE(
@@ -1432,9 +1440,15 @@ Maybe<bool> Object::SetPropertyWithAccessor(LookupIterator* it,
 
     PropertyCallbackArguments args(isolate, info->data(), *receiver, *holder,
                                    should_throw);
-    args.Call(call_fun, name, value);
+    Handle<Object> result = args.Call(call_fun, name, value);
+    // In the case of AccessorNameSetterCallback, we know that the result value
+    // cannot have been set, so the result of Call will be null.  In the case of
+    // AccessorNameBooleanSetterCallback, the result will either be null
+    // (signalling an exception) or a boolean Oddball.
     RETURN_VALUE_IF_SCHEDULED_EXCEPTION(isolate, Nothing<bool>());
-    return Just(true);
+    if (result.is_null()) return Just(true);
+    DCHECK(result->BooleanValue() || should_throw == DONT_THROW);
+    return Just(result->BooleanValue());
   }
 
   // Regular accessor.
@@ -5781,17 +5795,10 @@ Maybe<bool> JSObject::DefineOwnPropertyIgnoreAttributes(
             it->TransitionToAccessorPair(accessors, attributes);
           }
 
-          Maybe<bool> result =
-              JSObject::SetPropertyWithAccessor(it, value, should_throw);
-
-          if (current_attributes == attributes || result.IsNothing()) {
-            return result;
-          }
-
-        } else {
-          it->ReconfigureDataProperty(value, attributes);
+          return JSObject::SetPropertyWithAccessor(it, value, should_throw);
         }
 
+        it->ReconfigureDataProperty(value, attributes);
         return Just(true);
       }
       case LookupIterator::INTEGER_INDEXED_EXOTIC: