[webkit-reviews] review requested: [Bug 120535] Require layout when -webkit-overflow-scrolling changes : [Attachment 210129] Patch and layout test

[bugzilla-daemon at webkit.org]

Daniel Bates <dbates at webkit.org> has asked  for review:
Bug 120535: Require layout when -webkit-overflow-scrolling changes
https://bugs.webkit.org/show_bug.cgi?id=120535

Attachment 210129: Patch and layout test
https://bugs.webkit.org/attachment.cgi?id=210129&action=review

------- Additional Comments from Daniel Bates <dbates at webkit.org>
I'm unhappy with the layout test included with the patch, which tests that a
change to -webkit-overflow-scrolling causes a repaint. I tried to write a test
to show that -webkit-overflow-scrolling creates a stacking context by detecting
a difference in an element's z-index after changing the value of it's property
-webkit-overflow-scrolling from auto to touch. I was unclear how to write such
a test given the constraints that we only set z-index to 0 on an element with
auto z-index, -webkit-overflow-scrolling: touch, and overflow:
auto/hidden/scroll.  Does anyone have any insight/suggestions on how to write
such a test or knows of a better way to test that we perform a layout when the
value of -webkit-overflow-scrolling changes?