There is a few places where ComposedShadowTreeWalker is used directly. They should be push behind NodeRenderingTraversal to make CSTW usage optional.
Created attachment 182060 [details] Patch
Comment on attachment 182060 [details] Patch Attachment 182060 [details] did not pass mac-ews (mac): Output: http://queues.webkit.org/results/15762805
Created attachment 182067 [details] Patch
Created attachment 182071 [details] Patch
Comment on attachment 182071 [details] Patch Clearing flags on attachment: 182071 Committed r139325: <http://trac.webkit.org/changeset/139325>
All reviewed patches have been landed. Closing bug.