Make IdentityAccessorImplTest a friend of IdentityTestEnvironment.

This allows us to use a private constructor of IdentityTestEnvironment
while doing a gradual conversion to IdentityManager.

Change-Id: Ifc6d57bfd39a76c4faef3726f8b49f38041509af
Bug: 933109
Reviewed-on: https://chromium-review.googlesource.com/c/1498475
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Lowell Manners <lowell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637281}
2 files changed