Change GaiaCookieManagerService to take gaia_id along with account_id

The multilogin code assumes that accountID is Gaia ID which is not true
for chromeOS. GaiaCookieManagerService does not have any way to get
gaia_id from account_id. It is created from AccountsCookieMutatorImpl.
So AccountsCookieMutatorImpl now takes a account_tracker_service pointer
and passes a vector of pairs (CoreAccountId, std::string gaia_id) to
the GaiaCookieManagerService.

This is the first part of the cl to fix the bug. The second part is to
fix OauthMultiLoginHelper class.

Bug: 956503
Change-Id: I6ff7ceafb6a1a3ca29e8f7630596ceb659d8ea73
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1624189
Reviewed-by: David Roger <droger@chromium.org>
Reviewed-by: John Wu <jzw@chromium.org>
Commit-Queue: Tanmoy Mollik <triploblastic@google.com>
Cr-Commit-Position: refs/heads/master@{#665891}