GitLab

Update IdentityTestWithSignin to manifest v2 and remove the allowance
for manifest v1 extensions.

Bug: 816679

Change-Id: I0312986394cf10c58f31884284f7830df947feea
Reviewed-on: https://chromium-review.googlesource.com/1014600Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551804}