router.js

import Router from 'ember-router';
import on from 'ember-evented/on';
import { scheduleOnce } from 'ember-runloop';
const { newrelic } = window;
const { timing } = window.performance;

export default Router.extend({
  location: config.locationType,

  _start: on('didTransition', function() {
    scheduleOnce('afterRender', this, '_finish');
  }),
  
  _finish() {
    let seconds = (Date.now() - timing.domComplete) / 1000;
    newrelic.addPageAction(this.get('url'), seconds);
  }
});

I'm curious how you've found this in practice? After initial render, timing.domComplete never changes even if you navigate to another page so this seems like a skewed metric?