In Bug 183862 I updated the sandbox to allow reading of ViewBridge preferences from the user's local preferences. I should also have granted permission to read the global preferences.
Created attachment 340231 [details]
Comment on attachment 340231 [details]
Clearing flags on attachment: 340231
Committed r231728: <https://trac.webkit.org/changeset/231728>
All reviewed patches have been landed. Closing bug.