Right now if APZ is enabled in webrender (by commenting out [1]) and the reftests are run, they fail for reasons unrelated to correctness. Specifically, APIs like DOMWindowUtils.setAsyncScrollOffset are not implemented with webrender. We should make those work with webrender, so that the tests fail for correctness reasons. [1] http://searchfox.org/mozilla-central/rev/35b37316149108d53a02fb8498e250ea8a22ab5d/widget/nsBaseWidget.cpp#1262

^ many failures, but they're all correctness. So I think I can land the patches (but keep APZ disabled).

Comment on attachment 8871396 [details] Bug 1367837 - Expose a testing helper method to get an APZC instance from the layers id and scroll id. https://reviewboard.mozilla.org/r/142876/#review147004

Comment on attachment 8871397 [details] Bug 1367837 - Implement some APZ test util APIs for webrender. https://reviewboard.mozilla.org/r/142878/#review147016

Comment on attachment 8871395 [details] Bug 1367837 - Have the CompositorBridgeParent::FlushApzRepaints function take a layers id instead of a layer tree. https://reviewboard.mozilla.org/r/142874/#review147134

Comment on attachment 8871397 [details] Bug 1367837 - Implement some APZ test util APIs for webrender. https://reviewboard.mozilla.org/r/142878/#review147326

Pushed by kgupta@mozilla.com: https://hg.mozilla.org/projects/graphics/rev/b657891b5b02 Have the CompositorBridgeParent::FlushApzRepaints function take a layers id instead of a layer tree. r=dvander https://hg.mozilla.org/projects/graphics/rev/db86dd808a1a Expose a testing helper method to get an APZC instance from the layers id and scroll id. r=botond https://hg.mozilla.org/projects/graphics/rev/9c246299ad82 Implement some APZ test util APIs for webrender. r=botond,dvander

https://hg.mozilla.org/mozilla-central/rev/b657891b5b02 https://hg.mozilla.org/mozilla-central/rev/db86dd808a1a https://hg.mozilla.org/mozilla-central/rev/9c246299ad82