Change identity_accessor_impl to use CoreAccountId as account_id

Bug: 959157
Change-Id: Ic8d53f154c0065a14a9841fbe2eea44b87f1250f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1735381Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Tanmoy Mollik <triploblastic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684282}

services/identity/identity_accessor_impl.cc

@@ -100,7 +100,8 @@ void IdentityAccessorImpl::OnPrimaryAccountSet(
   OnAccountStateChange(primary_account_info.account_id);
 }
 
-void IdentityAccessorImpl::OnAccountStateChange(const std::string& account_id) {
+void IdentityAccessorImpl::OnAccountStateChange(
+    const CoreAccountId& account_id) {
   base::Optional<AccountInfo> account_info =
       identity_manager_
           ->FindExtendedAccountInfoForAccountWithRefreshTokenByAccountId(

services/identity/identity_accessor_impl.h

@@ -59,7 +59,7 @@ class IdentityAccessorImpl : public mojom::IdentityAccessor,
 
   // Notified when there is a change in the state of the account
   // corresponding to |account_id|.
-  void OnAccountStateChange(const std::string& account_id);
+  void OnAccountStateChange(const CoreAccountId& account_id);
 
   // Gets the current state of the account represented by |account_info|.
   AccountState GetStateOfAccount(const CoreAccountInfo& account_info);