Handle native callbacks without getters.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1049 matching lines @@
 
 static i::Handle<i::AccessorInfo> MakeAccessorInfo(
       v8::Handle<String> name,
       AccessorGetter getter,
       AccessorSetter setter,
       v8::Handle<Value> data,
       v8::AccessControl settings,
       v8::PropertyAttribute attributes,
       v8::Handle<AccessorSignature> signature) {
   i::Handle<i::AccessorInfo> obj = FACTORY->NewAccessorInfo();
-  ASSERT(getter != NULL);
   SET_FIELD_WRAPPED(obj, set_getter, getter);
   SET_FIELD_WRAPPED(obj, set_setter, setter);
   if (data.IsEmpty()) data = v8::Undefined();
   obj->set_data(*Utils::OpenHandle(*data));
   obj->set_name(*Utils::OpenHandle(*name));
   if (settings & ALL_CAN_READ) obj->set_all_can_read(true);
   if (settings & ALL_CAN_WRITE) obj->set_all_can_write(true);
   if (settings & PROHIBITS_OVERWRITING) obj->set_prohibits_overwriting(true);
   obj->set_property_attributes(static_cast<PropertyAttributes>(attributes));
   if (!signature.IsEmpty()) {
@@ skipping 5445 matching lines @@
 
   v->VisitPointers(blocks_.first(), first_block_limit_);
 
   for (int i = 1; i < blocks_.length(); i++) {
     v->VisitPointers(blocks_[i], &blocks_[i][kHandleBlockSize]);
   }
 }
 
 
 } }  // namespace v8::internal