Currently APZ does not cause scrollbar initiated scrolling to be async. I've been working in fixing this and I'd like some help testing it out before enabling it on Nightly. If you're interested please flip 'apz.drag.enabled' to true and restart. If you find any issue please make it block https://bugzilla.mozilla.org/show_bug.cgi?id=1211610.
I've got a test page here to confirm that it's turned on properly: http://people.mozilla.org/~bgirard/scroll_no_paint.html Scrolling on this page is slow in FF because it hits a performance bugs in layer construction code. However with APZ the scrolling is smooth and a bit checkerboard-y instead. If you have 'layers.acceleration.draw-fps' set you should notice the left most FPS counter at 60 FPS while the middle counter will be much lower. This is APZ handling the scroll. Happy Testing, Benoit _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
