Removed unused callback |shared_url_loader_factory_getter_| from GCMS

This repeating callback got introduced along with crrev.com/c/1630162
but it's not used anywhere, so let's remove it.

Bug: 939372
Change-Id: I772d7c766da0669b4b11fa55a77e7adbb3c483cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1660445Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Lowell Manners <lowell@chromium.org>
Commit-Queue: Mario Sanchez Prada <mario@igalia.com>
Cr-Commit-Position: refs/heads/master@{#669595}

components/signin/core/browser/gaia_cookie_manager_service.h

@@ -371,8 +371,7 @@ class GaiaCookieManagerService : public GaiaAuthConsumer,
   GaiaAccountsInCookieUpdatedCallback gaia_accounts_updated_in_cookie_callback_;
   GaiaCookieDeletedByUserActionCallback
       gaia_cookie_deleted_by_user_action_callback_;
-  base::RepeatingCallback<scoped_refptr<network::SharedURLLoaderFactory>()>
-      shared_url_loader_factory_getter_;
+
   std::unique_ptr<GaiaAuthFetcher> gaia_auth_fetcher_;
   std::unique_ptr<signin::UbertokenFetcherImpl> uber_token_fetcher_;
   ExternalCcResultFetcher external_cc_result_fetcher_;