osr-discourse-src/app/assets/javascripts/discourse/routes/user-activity.js.es6

export default Discourse.Route.extend({
  model: function() {
    return this.modelFor('user');
  },

  setupController: function(controller, user) {
    this.controllerFor('user-activity').set('model', user);

    // Bring up a draft
    var composerController = this.controllerFor('composer');
    controller.set('model', user);
    if (Discourse.User.current()) {
      Discourse.Draft.get('new_private_message').then(function(data) {
        if (data.draft) {
          composerController.open({
            draft: data.draft,
            draftKey: 'new_private_message',
            ignoreIfChanged: true,
            draftSequence: data.draft_sequence
          });
        }
      });
    }
  }
});