Per https://phabricator.wikimedia.org/T104902#1494035:
Add to NavigationTiming extension and collect in Statsd-Graphite and Coal:
- unloadEventStart / unloadEventEnd.
- redirectStart / redirectEnd.
- domainLookupStart / domainLookupEnd.
- domLoading.
- domContentLoadedEventStart / domContentLoadedEventEnd.
Also add mediaWikiLoadStart (relative to navigationStart), and change mediaWikiLoadComplete to be relative to navigationStart instead of mediaWikiLoadStart.
Alternatively, we could give them different names (e.g. mwLoadStart and mwLoadEnd). Use of performance.mark was added by 7076ee791fe3e99 as "mediaWikiStartUp". (Can be retrieved with performance.getEntriesByName?)