948531 - Tab switch causes page to first be rebuilt without active layers

Status: VERIFIED FIXED

(Core :: Graphics: Layers, defect)

Description

[Benoit Girard (:BenWa)]

STR:
1) Open http://people.mozilla.org/~bgirard/browser_tests/gpu_bound/?1000
2) Switch to another tab for a few seconds
3) Switch back

You'll see the page first repaint without any active layers for what appears to be two frames then switch to active layers. Making the first 3 frames very jerky.

Comment 1

[Benoit Girard (:BenWa)]

The problem is also visible on page load (might need to have the image cached).

We don't need to wait at all to predict that this animation will continue.

Comment 2

[Benoit Girard (:BenWa)]

Problem is here:
http://mxr.mozilla.org/mozilla-central/source/layout/base/ActiveLayerTracker.cpp#207

We should be also be checking if there's an active animation.

Comment 3

[Benoit Girard (:BenWa)]

Attachment: patch

Comment 4

[Benoit Girard (:BenWa)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/d8fb025ca7d2

Comment 5

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Wow, did we really not do this in any way before? Thanks for fixing!

Comment 6

[Ryan VanderMeulen [:RyanVM]]

This has the misfortune of landing on top of debug mochitest bustage. Post-backout, OSX 10.6 debug mochitest-5 was orange. Going through what landed (and applicable Try pushes), this was the most likely candidate. Backing out for now. If this turns out to be OK, I will re-land it.
https://hg.mozilla.org/integration/mozilla-inbound/rev/9389007688e1

https://tbpl.mozilla.org/php/getParsedLog.php?id=31833565&tree=Mozilla-Inbound

Comment 7

[Ryan VanderMeulen [:RyanVM]]

As predicted by BenWa, this wasn't at fault. Relanded :)

https://hg.mozilla.org/integration/mozilla-inbound/rev/d551609a45a9

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/d551609a45a9

Comment 9

[Ada [:adalucinet]]

Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:29.0) Gecko/20100101 Firefox/29.0

Reproduced on Nightly from 2013-12-09 with STR from comment 0. 
Verified as fixed with Firefox 29 beta 4 (Build ID: 20140331125246) on Mac OS X 10.6: the page repaints with active layers after reloading or switching tabs.