1402925 - Don't set a compositor animation id in StackingContextHelper if the animation has ended

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement, P1)

Description

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

Ethan found a problem in my patch for bug 1402439 and wrote a patch for it. Details at https://bugzilla.mozilla.org/show_bug.cgi?id=1402439#c25. Basically, when the animation ends on the content side we need to reset the compositor animations id that we put in the StackingContextHelper back to zero, otherwise the compositor will ignore the transform/opacity in the StackingContextHelper and instead wait for the animation to provide a value. Since the animation is over, that value will never be provided, and so things might show up in the wrong place or with the wrong opacity. That's what was happening if the layout/reftests/css-animation/stacking-context-transform-none-with-fill-forwards.html file was loaded in the browser with layers-free enabled.

Comment 1

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

Attachment: Bug 1402925 - Reset the animation id passed to the StackingContextHelper if there is no animation.

Review commit: https://reviewboard.mozilla.org/r/183280/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/183280/

Comment 2

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

Comment on attachment 8911901 [details]
Bug 1402925 - Reset the animation id passed to the StackingContextHelper if there is no animation.

https://reviewboard.mozilla.org/r/183280/#review188442

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4c4b18031f80
Reset the animation id passed to the StackingContextHelper if there is no animation. r=kats

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/4c4b18031f80