1526725 - Should we make default of "wheel" (and "DOMMouseScroll", "MozPixelMouseScroll") event listeners on root "passive"?

Status: RESOLVED FIXED

(Core :: DOM: Events, enhancement, P3)

Description

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

According to the blog-post, Chrome 73 starts to treat "wheel" and "mousewheel" event listeners on root as passive event listeners by default like touchstart and touchmove. Shouldn't we follow this?

Comment 1

[Olli Pettay [:smaug][[e-mail]]]

Yeah, I think so.
IIRC also kats was in favor of making the change.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Sounds good to me

Comment 3

[Olli Pettay [:smaug][[e-mail]]]

FWIW, I couldn't immediately find any telemetry telling whether this change could improve performance.

Comment 4

[Olli Pettay [:smaug][[e-mail]]]

FWIW, Chrome has at least some regressions https://bugs.chromium.org/p/chromium/issues/detail?id=931466

Comment 5

[Olli Pettay [:smaug][[e-mail]]]

And regressions with React https://github.com/facebook/react/issues/14856

Comment 6

[Emilio Cobos Álvarez (:emilio)]

Attachment: Test-case

I just found a website (https://www.ashler.design/) which scrolls super-slow in Firefox because of this.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1526725 - Make dom.event.default_to_passive_touch_listeners a static pref. r=smaug

Comment 8

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1526725 - Make wheel events passive by default on Nightly. r=smaug

This turned out to not be the root cause for that broken site, but I wrote the
code so... I enabled it on Nightly only to see if there's fallout, I don't think
we need to ship this in the near term, your call.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2bbbaccb0d06
Make dom.event.default_to_passive_touch_listeners a static pref. r=smaug
https://hg.mozilla.org/integration/autoland/rev/98bafb894b5d
Make wheel events passive by default on Nightly. r=smaug

Comment 10

[Dorel Luca [:dluca]]

Backed out 2 changesets (bug 1526725) as per dev's request

Push that was backed out:
https://treeherder.mozilla.org/#/jobs?repo=autoland&group_state=expanded&revision=98bafb894b5d09731458584a95e955c9dbc4cace

Backout:
https://hg.mozilla.org/integration/autoland/rev/ecb7e12f7e05e1b22a69c04ada0885790f7eafa1

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f1654b5e2746
Make dom.event.default_to_passive_touch_listeners a static pref. r=smaug
https://hg.mozilla.org/integration/autoland/rev/dd177138d6d2
Make wheel events passive by default on Nightly. r=smaug

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/bd3462eeb191
followup: Fix a test that's intermittently failing more often.

Comment 13

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/f1654b5e2746
https://hg.mozilla.org/mozilla-central/rev/dd177138d6d2
https://hg.mozilla.org/mozilla-central/rev/bd3462eeb191

Comment 14

[Eric Shepherd [:sheppy]]

Looks like this change is only enabled on nightly, unless there's another bug already fixed to enable it for release builds (in which case it should be linked to this bug for us to find it). Please make sure the bug to enable it by default is marked DDN. Thanks!

Comment 15

[Eric Shepherd [:sheppy]]

Noted this change on https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Experimental_features#DOM.