Multi-pass scrollbar resolution is only needed for traditional scrollbars. Overlay scrollbars don't affect layout.
Created attachment 221656 [details]
Attachment 221656 [details] did not pass style-queue:
ERROR: Source/WebCore/platform/ScrollView.cpp:560: Should have only a single space after a punctuation in a comment. [whitespace/comments] 
Total errors found: 1 in 2 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Comment on attachment 221656 [details]
I think this might be a no-op after r155660?
Re-opened since this is blocked by bug 127354
Rolled out in <http://trac.webkit.org/changeset/162447>, and confirmed that this fixed the test.
Looks like this is a good patch overall, but straightening its effects on accessibility seems tricky. It manifested in really weird behavior, see bug 127323.
> I think this might be a no-op after r155660?
Definitely still not a no-op, because rolling it out changed test behavior.
Yeah, I confirmed yesterday that it does eliminate calls to visibleContentsResized()
Relanded in https://trac.webkit.org/r162515
It tries to resolve accessibility test flakiness by forcing layout in the test. The real bug might be in the AccessibilityController.