Markus suggested a simplification we can make to the AddingOwnLayer() call sites in ContainerState::ProcessDisplayItems(), as a follow-up to the change we made in bug 1367488. Filing this bug to track.

Comment on attachment 8874048 [details] Bug 1369910 - Simplify AddingOwnLayer() call sites in ProcessDisplayItems(). https://reviewboard.mozilla.org/r/145498/#review149446 ::: layout/painting/FrameLayerBuilder.cpp:4215 (Diff revision 1) > - *animatedGeometryRoot != mBuilder->RootReferenceFrame()) || > - (IsScrollThumbLayer(item) && mManager->IsWidgetLayerManager())) { > + // For scrolbar thumbs, the clip we care about is the overflow:hidden > + // clip on the scrollbar. We should fix this comment as well. "... is the clip added by the slider frame." Oh and you have a typo in the word scrollbar.

Pushed by bballo@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/5450b06e79e5 Simplify AddingOwnLayer() call sites in ProcessDisplayItems(). r=mstange

Backed out for various crashes like https://treeherder.mozilla.org/logviewer.html#?job_id=104601576&repo=autoland https://hg.mozilla.org/integration/autoland/rev/4eac7b44eb98

This had some reftest failures too. Be sure to double-check those on Try before relanding as well.

My Try push was clean, but only included tests on Linux. The failing tests are all on Mac and Windows. I'll run tests on all platforms before landing an updated patch.

I *think* I've gotten this to the point where the remaining Try failures [1] are known intermittents, so I'm going to post my updated patch for review. [1] https://treeherder.mozilla.org/#/jobs?repo=try&revision=52d51efc940ff8ce17b0f5d219115cfba343cc8a

Whoops, that dependency change was unintentional.

Comment on attachment 8874048 [details] Bug 1369910 - Simplify AddingOwnLayer() call sites in ProcessDisplayItems(). As this patch has changed significantly since it was originally reviewed, I would like a re-review.

Comment on attachment 8874048 [details] Bug 1369910 - Simplify AddingOwnLayer() call sites in ProcessDisplayItems(). Looks good to me!

Pushed by bballo@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/337ed61025fe Simplify AddingOwnLayer() call sites in ProcessDisplayItems(). r=mstange