Support both ways for Chrome to report on first paint time

[John Riviello]

The Chrome team is planning to migrate away from chrome.loadTimes() to navigation timing and expose first paint time through a standard API. Once that new standard API is available, Surf-N-Perf should favor that over chrome.loadTimes().

As of June 2016 this issue is blocked until that API is available. See chromium issue 621512 to track the status.

[John Riviello]

Update: the Paint Timing API has shipped in Chrome 60, so we should use that when possible.

A few article links that explain it further:

• https://blog.chromium.org/2017/06/chrome-60-beta-paint-timing-api-css.html
• https://developers.google.com/web/updates/2017/06/user-centric-performance-metrics
• https://css-tricks.com/paint-timing-api/

[John Riviello]

Chrome is starting to provide deprecation warnings in dev tools regarding the use of chrome.loadTimes() and pushing devs to https://www.chromestatus.com/features/5637885046816768