In https://github.com/electron/electron/commit/7613afe6d70eadd7446db921918dca086cd324c0 I had to disable the check that validates that the constructor is called on the right thread, because the check fails when the tests run.

Let's make sure the check doesn't fail and re-enable it. Or refactor so that the thread affinity is not required and remove the check.
atom/browser/api/atom_api_app.cc
auto status = content::GetFeatureStatus();
  return mate::ConvertToV8(isolate,
                           status ? *status : base::DictionaryValue());
}
void App::EnableMixedSandbox(mate::Arguments* args) {
  if (Browser::Get()->is_ready()) {
    args->ThrowError("app.enableMixedSandbox() can only be called "
                     "before app is ready");
    return;
  }
  auto command_line = base::CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(::switches::kNoSandbox)) {
#if defined(OS_WIN)
    const base::CommandLine::CharType* noSandboxArg = L"--no-sandbox";
#else
    const base::CommandLine::CharType* noSandboxArg = "--no-sandbox";
#endif
    
    base::CommandLine::StringVector modified_command_line;
    for (auto& arg : command_line->argv()) {
      if (arg.compare(noSandboxArg) != 0) {
        modified_command_line.push_back(arg);
      }
    }
    command_line->InitFromArgv(modified_command_line);
  }
  command_line->AppendSwitch(switches::kEnableMixedSandbox);
}
#if defined(OS_MACOSX)
bool App::MoveToApplicationsFolder(mate::Arguments* args) {