The test tiled-drawing/scrolling/scroll-snap/scroll-snap-mandatory-mainframe-vertical.html is a flaky failure still.
A proposed fix was given in r209070 https://trac.webkit.org/changeset/209070/webkit
The test was still flaky on El Capitan and Sierra.
@@ -1,6 +1,7 @@
PASS div scrolled to next window.
-PASS div honored snap points.
+FAIL div did not snap back to proper location. (610 vs. 600)
PASS successfullyParsed is true
+Some tests failed.
I have been unable to reproduce the failure on both debug and release for Sierra.
Marked as flaky failure on Mac WK2:
*** This bug has been marked as a duplicate of bug 165196 ***