[webkit-reviews] review requested: [Bug 115570] Remove concept of younger and older shadow trees : [Attachment 200513] with test updates

[bugzilla-daemon at webkit.org]

Antti Koivisto <koivisto at iki.fi> has asked  for review:
Bug 115570: Remove concept of younger and older shadow trees
https://bugs.webkit.org/show_bug.cgi?id=115570

Attachment 200513: with test updates
https://bugs.webkit.org/attachment.cgi?id=200513&action=review