| Index: src/bootstrapper.cc | 
| diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc | 
| index 39840310288d26d77d0b2cb56fe8458885977345..71e43d48efa8f5fcf480a037f355ef7d14306042 100644 | 
| --- a/src/bootstrapper.cc | 
| +++ b/src/bootstrapper.cc | 
| @@ -1003,12 +1003,19 @@ static void InstallError(Isolate* isolate, Handle<JSObject> global, | 
| JSObject::AddProperty(prototype, factory->constructor_string(), error_fun, | 
| DONT_ENUM); | 
|  | 
| -    Handle<JSFunction> to_string_fun = | 
| -        SimpleInstallFunction(prototype, factory->toString_string(), | 
| -                              Builtins::kErrorPrototypeToString, 0, true); | 
| -    to_string_fun->shared()->set_native(true); | 
| +    if (context_index == Context::ERROR_FUNCTION_INDEX) { | 
| +      Handle<JSFunction> to_string_fun = | 
| +          SimpleInstallFunction(prototype, factory->toString_string(), | 
| +                                Builtins::kErrorPrototypeToString, 0, true); | 
| +      to_string_fun->shared()->set_native(true); | 
| +      isolate->native_context()->set_error_to_string(*to_string_fun); | 
| +    } else { | 
| +      DCHECK(context_index != Context::ERROR_FUNCTION_INDEX); | 
| +      DCHECK(isolate->native_context()->error_to_string()->IsJSFunction()); | 
| + | 
| +      InstallFunction(prototype, isolate->error_to_string(), | 
| +                      factory->toString_string(), DONT_ENUM); | 
|  | 
| -    if (context_index != Context::ERROR_FUNCTION_INDEX) { | 
| Handle<JSFunction> global_error = isolate->error_function(); | 
| CHECK(JSReceiver::SetPrototype(error_fun, global_error, false, | 
| Object::THROW_ON_ERROR) | 
| @@ -2698,6 +2705,13 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate, | 
| Accessors::FunctionSetPrototype(callsite_fun, proto).Assert(); | 
| } | 
| } | 
| + | 
| +  {  // -- E r r o r | 
| +    Handle<JSFunction> make_err_fun = InstallFunction( | 
| +        container, "make_generic_error", JS_OBJECT_TYPE, JSObject::kHeaderSize, | 
| +        isolate->initial_object_prototype(), Builtins::kMakeGenericError); | 
| +    make_err_fun->shared()->DontAdaptArguments(); | 
| +  } | 
| } | 
|  | 
|  | 
|  |