HysteresisActivity cannot be used in the UIProcess because it uses a WebCore Timer internally.
<rdar://problem/33086442>
Created attachment 315847 [details] Patch
Comment on attachment 315847 [details] Patch Clearing flags on attachment: 315847 Committed r219641: <http://trac.webkit.org/changeset/219641>
All reviewed patches have been landed. Closing bug.