1210906 - Implement performance.timing.firstPaint

Status: RESOLVED DUPLICATE of bug 1377251

(Core :: DOM: Core & HTML, defect)

Description

[(not reading bugmail) Nick Desaulniers [:\n]]

Looks like IE9+ and Chrome have this:
https://github.com/furoshiki/FirstPaintSetter.js/blob/master/FirstPaintSetter.js
https://github.com/addyosmani/timing.js/blob/master/timing.js#L44-L64

I can't seem to find a spec on this, but maybe it has a different name?
http://w3c.github.io/navigation-timing/#processing-model

Comment 1

[Boris Zbarsky [:bzbarsky]]

Please talk to the Web Performance working group about what's going on here?  This used to be in some early drafts 5 years ago, iirc, but got removed at some point as the spec was being finalized, so I'm surprised to hear that IE and Chrome are shipping implementations.  :(

Comment 2

[:Harald Kirschner :digitarald]

The spec is moving forward: https://github.com/wicg/paint-timing , not as performance.timing.firstPaint but as PerformanceEntry

Markus, now that we have bug 1307242 it fits the spec:

> "first-paint" entries contain a DOMHighResTimeStamp reporting the time when the browser first rendered after navigation. This excludes the default background paint, but includes non-default background paint. This is the first key moment developers care about in page load – when the browser has started to render the page.

I would propose to expose this behind a pref to allow developers to start benchmarking against it, compare to what Chrome provides and give us feedback.

Comment 3

[Joel Maher ( :jmaher ) (UTC -8)]

:mstange, this feature is needed for measuring pageload under the new quantum tests we are standing up.  Right now (bug 1370320), we are getting the tooling in place and using 'onload', is this a bug you are planning to implement soon?

Comment 4

[Joel Maher ( :jmaher ) (UTC -8)]

oops, not bug 1370320, but bug 1370293 instead.

Comment 5

[Robert Wood [:rwood]]

Hi :mstange,

We were talking on IRC about how to have talos tests measure first-non-blank-paint (Bug 1369417).

From https://bugzilla.mozilla.org/show_bug.cgi?id=1369417#c10

<mconley> we might need Platform to expose this value somehow: http://searchfox.org/mozilla-central/source/layout/base/nsPresContext.h#1417

Is this possible? Is this what you were planning for in this bug? Thanks!

Comment 6

[Chris Peterson [:cpeterson]]

Chrome exposes first paint time in window.chrome.loadTimes().firstPaintTime.

Comment 7

[:Harald Kirschner :digitarald]

Closing as performance.timing.firstPaint is Chrome only and new specs solve this. Re-open if the other bug doesn't address this.