This is a meta bug that tracks all the issues that need to be fixed before we can enable APZ on Fennec for nightly builds.
Created attachment 8685605 [details] [diff] [review] Randall's patch Randall had a patch in his queue to enable C++ APZ by default. Posting it here since this bug is eventually going to be used to land the patch that does this. However we'll need to update the patch so that it only does this for nightly.
(Actually it would also be better to put the MOZ_ANDROID_APZ=1 into mobile/android/confvars.sh rather than configure.in)
Comment on attachment 8685605 [details] [diff] [review] Randall's patch Should we also add something to confvars with a NIGHTLY_BUILD check?
Created attachment 8686145 [details] [diff] [review] Patch Yeah this is actually all that should be needed to flip it on. Seems to do the job locally at least.
Created attachment 8691619 [details] [diff] [review] 0001-Bug-1206872-meta-Enable-APZ-on-fennec-on-nightly-builds-15112415-df71342.patch
Bug 1224015 landed. So you can push this when ready.
We still need to do something about bug 1225508 - if you don't have any layout side fixes off the top of your head then I'm fine with landing the workaround that I have. I can do that tomorrow.
Oh yeah. Probably a fix along the lines of your "My bad attempt at fixing it in layout" patch is the way to go. I'll work on getting that landable. The workaround is reasonable so you can land that if you want to go ahead before that's ready.
This part https://hg.mozilla.org/integration/mozilla-inbound/rev/0aa2e79b9252#l4.13 of bug 1224015 appears to have fixed bug 1225508 for me. This makes sense to me. (I tested with and without that hunk.) So I think you are good to land without the workaround.
(Moving discussion to bug 1225508)
Created attachment 8693007 [details] [diff] [review] Enable APZ on nightly builds I think we're ready to turn this on. Happy thanksgiving!
Comment on attachment 8693007 [details] [diff] [review] Enable APZ on nightly builds Great work getting to this point!