1389215 - Stop layerizing in response to margin animations

Status: RESOLVED FIXED

(Core :: Web Painting, enhancement)

Description

[Markus Stange [:mstange]]

We currently create a layer for an element if JavaScript animates any of the margin properties on the element.

I'm not aware of any pages where this benefits us. I've only seen it cause unnecessary invalidations because of margin changes that were incorrectly detected as animations.
For example, on http://bazqux.com/ (an RSS reader, requires an account), as you scroll over posts, there's some JS that highlights the post that you're currently looking at, and sets margin-left to zero a few times. So in this case the margin doesn't even change, and it still gets detected as an animation.

Comment 1

[Markus Stange [:mstange]]

Attachment: Bug 1389215 - Don't layerize in response to margin changes.

Review commit: https://reviewboard.mozilla.org/r/167236/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/167236/

Comment 2

[Matt Woodrow (:mattwoodrow)]

Comment on attachment 8895963 [details]
Bug 1389215 - Don't layerize in response to margin changes.

https://reviewboard.mozilla.org/r/167236/#review172492

::: layout/painting/ActiveLayerTracker.cpp:444
(Diff revision 1)
>    }
>    return nsLayoutUtils::HasEffectiveAnimation(aFrame, aProperty);
>  }
>  
>  /* static */ bool
>  ActiveLayerTracker::IsOffsetOrMarginStyleAnimated(nsIFrame* aFrame)

Could rename this function now that margins aren't taken into account.

Comment 3

[Markus Stange [:mstange]]

Comment on attachment 8895963 [details]
Bug 1389215 - Don't layerize in response to margin changes.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/167236/diff/1-2/

Comment 4

[Markus Stange [:mstange]]

Comment on attachment 8895963 [details]
Bug 1389215 - Don't layerize in response to margin changes.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/167236/diff/2-3/

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ae6148ddda6b
Don't layerize in response to margin changes. r=mattwoodrow

Comment 6

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/ae6148ddda6b

Comment 7

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

I see an improvement in memory on AWSY:
== Change summary for alert #8755 (as of August 13 2017 01:16 UTC) ==

Improvements:

  5%  Resident Memory summary macosx64-stylo opt stylo     667,672,371.49 -> 637,141,298.34

For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=8755