If tlsdate is not able to sync the date/time (e.g.  bug 800598  or https://bugs.chromium.org/p/chromium/issues/detail?id=127019#c92 ), session_manager waits forever when retrieving server-backed state keys, which makes chrome hang on enrollment forever.

If we're not going to drop the dependency on tlsdate, introduce a sensible timeout either in session_manager or in chrome so the user gets an error message instead of a device which hangs.