Bumping this to P1 because doing this work is necessary to properly track the inclusions of PO2TS from AccountFetcherService and friends.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8442b70f28ef7a2039b0e6c19078cdd821aaced1

commit 8442b70f28ef7a2039b0e6c19078cdd821aaced1
Author: Colin Blundell <blundell@chromium.org>
Date: Mon Jan 14 16:24:45 2019

Move AccountFetcherService and dependencies into signin_internals

As we resolved on
https://bugs.chromium.org/p/chromium/issues/detail?id=911675,
AccountFetcherService and AccountTrackerService are conceptually a
single entity. Since AccountTrackerService is targeted for being
inside IdentityManager, AccountFetcherService should be as well.

This CL moves AccountFetcherService into the signin_internals GN target,
and additionally moves necessary dependencies to make "GN check" happy.
Note that we move avatar_icon_util.* into the shared target, as this
file holds a utility function that just manipulates an avatar icon URL.
That functionality is (at least at this time) fine to be shared
between clients and IdentityManager internals.

A followup CL will do a similar move for FakeAccountInfoFetcher.

Bug:  915149 
Change-Id: I8bfe4c7eebb1c320164521fd9580f481b5bd14fe
Reviewed-on: https://chromium-review.googlesource.com/c/1408910
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622471}
[modify] https://crrev.com/8442b70f28ef7a2039b0e6c19078cdd821aaced1/components/signin/core/browser/BUILD.gn

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/db4c61ad541d239d238588d65402ba066577ffb3

commit db4c61ad541d239d238588d65402ba066577ffb3
Author: Colin Blundell <blundell@chromium.org>
Date: Tue Jan 15 09:13:57 2019

Move FakeAccountFetcherService into signin_internals

Follows the corresponding change for the production class that was
made in
https://chromium-review.googlesource.com/c/chromium/src/+/1408910.

This CL also eliminates the
//components/signin/core/browser:test_support GN target, as it no
longer had any files. All dependents of that target now depend directly
on //components/signin/core/browser:internals_test_support, in the
course of being transitioned to use
//services/identity/public/cpp:test_support instead.

TBR=msarda@chromium.org

Bug:  915149 
Change-Id: Ia9a51fe8738ff2608bd1926902a2aefa1f17881d
Reviewed-on: https://chromium-review.googlesource.com/c/1408948
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622792}
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/chrome/browser/web_applications/bookmark_apps/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/chrome/test/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/components/browser_sync/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/components/invalidation/impl/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/components/search_provider_logos/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/components/signin/core/browser/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/components/signin/ios/browser/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/components/sync/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/ios/chrome/browser/signin/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/ios/web_view/BUILD.gn
[modify] https://crrev.com/db4c61ad541d239d238588d65402ba066577ffb3/services/identity/BUILD.gn