GitLab

Changes Identity so that none of its fields are optional. All Identity
objects are now either empty and invalid, or fully populated and refer
to a specific, concrete service instance that did, does, or may exist at
some point.

Bug: 902590,904240
Change-Id: I5b35909afb39b2588f0841d5b1713a6f7c06c800
Reviewed-on: https://chromium-review.googlesource.com/c/1333126Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Oksana Zhuravlova <oksamyt@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Ken Rockot <rockot@google.com>
Cr-Commit-Position: refs/heads/master@{#608634}