GitLab

This CL reverts d8bd981f, in effect relanding the changes to have
RemoteSuggestionsFetcherImpl and its unittest use IdentityManager. In
the interim I have landed a fix to the bug that necessitated
reversion of those CLs, i.e. the raciness between IdentityManager
getting updated on signin/signout and other SigninManager::Observers
getting updated on those same events
(fix is here:
 https://chromium-review.googlesource.com/c/chromium/src/+/883347).

To test this change, do the following:
- Sign in to Chrome on Android (in a chrome_apk build if building locally)
- Observe that there are personalized suggestions on the NTP
- Sign out
- Observe that there are different, generic suggestions on the NTP

You can also more generally that the suggestions get updated on various
transitions between a signed-out state and a signed-in state.

TBR=gambard@chromium.org

Bug: 798413
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I37d182718ef0b53a85be1a083f203aa0acdb3d8d
Reviewed-on: https://chromium-review.googlesource.com/888617
Commit-Queue: Colin Blundell <blundell@chromium.org>
Reviewed-by: Jan Krcal <jkrcal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532888}