It's possible we were triggering a null pointer dereference in some
cases of lost device recovery. I was unable to reproduce this in a test
so this fix is speculative.

Bug: chromium:871178
Change-Id: I55b7790eabb81c25489bdfd105b5f2cbeedcc8db
Reviewed-on: https://chromium-review.googlesource.com/1169955Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>