[s13n] Eliminate browser_state_keyed_service_factories.mm's references to signin internals factories

This CL adds EnsureFactoryAndDependeeFactoriesBuilt to
IdentityManagerFactory for iOS in order to eliminate the
references to signin internals factories from
browser_state_keyed_service_factories.mm.

The API ensures that AccountTrackerServiceFactory,
GaiaCookieManagerServiceFactory, IdentityManagerFactory,
and ProfileOAuth2TokenServiceFactory are built.

Bug: 931254
Change-Id: I9a5e812a71755a205e755b9f63bbaf3d4b3c977a
Reviewed-on: https://chromium-review.googlesource.com/c/1469802
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Commit-Queue: Miyoung Shin <myid.shin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631674}
3 files changed