* 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
std::string result_code;
    switch (val) {
      case JumpListResult::SUCCESS:
        result_code = "ok";
        break;
      case JumpListResult::ARGUMENT_ERROR:
        result_code = "argumentError";
        break;
      case JumpListResult::GENERIC_ERROR:
        result_code = "error";
        break;
      case JumpListResult::CUSTOM_CATEGORY_SEPARATOR_ERROR:
        result_code = "invalidSeparatorError";
        break;
      case JumpListResult::MISSING_FILE_TYPE_REGISTRATION_ERROR:
        result_code = "fileTypeRegistrationError";
        break;
      case JumpListResult::CUSTOM_CATEGORY_ACCESS_DENIED_ERROR:
        result_code = "customCategoryAccessDeniedError";
        break;
    }
    return ConvertToV8(isolate, result_code);
  }
};
#endif
template <>
struct Converter<Browser::LoginItemSettings> {
  static bool FromV8(v8::Isolate* isolate,