* Output of `node_modules/.bin/electron --version`: v4.0.0
* Operating System (Platform and Version): macOS 10.14.2

* Output of `node_modules/.bin/electron --version` on last known working Electron version (if applicable): 2.0.7

### Expected behavior

I should be able to call `app.setAccessibilitySupportEnabled(true)` during initialization, and the application should start and stay open.

### Actual behavior

The application starts and exits immediately if `app.setAccessibilitySupportEnabled(true)` is called during initialization. Same for passing in `false`.

### How to reproduce

Here is a simple project that shows this error. The application behaves as expected (does not exit immediately) when this line is commented out:
https://github.com/marisademeglio/electron4-setA11yTreeEnabled/blob/master/src/main/main.js#L27

  $ git clone https://github.com/marisademeglio/electron4-setA11yTreeEnabled.git
  $ yarn install
  $ yarn start

atom/browser/api/atom_api_app.cc
if (HasSingleInstanceLock())
    return true;
  base::FilePath user_dir;
  base::PathService::Get(DIR_USER_DATA, &user_dir);
  auto cb = base::Bind(&App::OnSecondInstance, base::Unretained(this));
  process_singleton_.reset(new ProcessSingleton(
      user_dir, base::Bind(NotificationCallbackWrapper, cb)));
  switch (process_singleton_->NotifyOtherProcessOrCreate()) {
    case ProcessSingleton::NotifyResult::LOCK_ERROR:
    case ProcessSingleton::NotifyResult::PROFILE_IN_USE:
    case ProcessSingleton::NotifyResult::PROCESS_NOTIFIED: {
      process_singleton_.reset();
      return false;
    }
    case ProcessSingleton::NotifyResult::PROCESS_NONE:
    default:  
      return true;
  }
}
void App::ReleaseSingleInstanceLock() {
  if (process_singleton_) {
    process_singleton_->Cleanup();
    process_singleton_.reset();
  }
}
bool App::Relaunch(mate::Arguments* js_args) {