Add IdentityTestEnvironment wrapper of identity_test_utils method

This small CL simply adds an IdentityTestEnv wrapper of an underlying
identity_test_utils method for convenience. The wrapper will be used
in an upcoming CL.

Bug: 917837
Change-Id: Ib62f1b4a6eea9a91bfc4ec0074bb5c1090907e1e
Reviewed-on: https://chromium-review.googlesource.com/c/1393326
Commit-Queue: Colin Blundell <blundell@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620279}
2 files changed