application.hbs

<nav>
  <ul>
    {{#if session.isAuthenticated}}
      <li>
        {{#link-to 'protected'}}Protected{{/link-to}}
      </li>
      <li>
        <button {{action 'logout'}}>
          Log out
        </button>
      </li>
    {{else}}
      <li>
        <button {{action 'login'}}>
          Log in with Google
        </button>
      </li>
    {{/if}}
  </ul>
</nav>

{{outlet}}

application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  session: Ember.inject.service('session'),

  actions: {
    login() {
      this.get('session').authenticate('authenticator:torii', 'google-oauth2-bearer');
    },
    logout() {
      this.get('session').invalidate();
    }
  }
});

protected.js

import Ember from 'ember';
import AuthenticatedRouteMixin from 'ember-simple-auth/mixins/authenticated-route-mixin';

export default Ember.Route.extend(AuthenticatedRouteMixin, {
  ajax: Ember.inject.service(),

  model: function() {
    return this.get('ajax').request('/protected');
  }
});