CrossProcessCompositorParent::AllocPLayerTransactionParent fails. This was papered over before because we returned a dummy LayerTransactionParent without a layer manager. I presume this breaks things somewhere. Now we explicitly check for success and that causes test fails when we don't have a shadow manager to forward things to. I have temporarily hacked that method to feign success. Change success to false to see what is going on. We should fix this properly.

Hi Matt, would you be able to look into this?

I added that dummy LayerTransactionParent iirc :) We have the problem where we have tests running with BasicLayers (not to be confused with BasicCompositor), and are expecting to be able to setup remote content. This really doesn't work at all any more. We don't have any tests that expect the rendering of this to work, nor do we need it for any shipping configuration. I think we should be fine just ignoring this until we have OMTC everywhere and this can all go away.

Is this still an issue for Mac where OMTC is enabled by default?

Try push with removal of the bogus code: https://treeherder.mozilla.org/#/jobs?repo=try&revision=74275c8492725e2fba074944500fdcba8c6db76f

I think I removed too much. Probably all we should do is flip that "success" return value from true to false. And then to fix bug 1322633 we can just not call InitAPZState if the success value is false. https://treeherder.mozilla.org/#/jobs?repo=try&revision=a2d662e65982b2fa92bffd3ccbdfe0bc12b54b81

Comment on attachment 8831434 [details] Bug 900745 - Remove bogus fallback codepath. https://reviewboard.mozilla.org/r/108008/#review109154

Pushed by kgupta@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/2f446632bf08 Remove bogus fallback codepath. r=mattwoodrow

Comment on attachment 8831434 [details] Bug 900745 - Remove bogus fallback codepath. Approval Request Comment [Feature/Bug causing the regression]: unknown, a long time ago [User impact if declined]: this fix by itself has no real user impact. this fix is needed for the fix in bug 1322633 to work, though. [Is this code covered by automated tests?]: yes [Has the fix been verified in Nightly?]: yes, in that all the automated tests are still green [Needs manual test from QE? If yes, steps to reproduce]: no [List of other uplifts needed for the feature/fix]: bug 1322633 [Is the change risky?]: no [Why is the change risky/not risky?]: it's a small one-line change that we meant to do a long time ago but never really mattered much. [String changes made/needed]: none

Comment on attachment 8831434 [details] Bug 900745 - Remove bogus fallback codepath. This fix is needed for the fix in bug 1322633. Aurora53+.

Comment on attachment 8831434 [details] Bug 900745 - Remove bogus fallback codepath. let's take this in beta52 as prerequisite for bug 1322633

Setting qe-verify- per Comment 10.