Preparation to convert GetPrimaryAccount to return CoreAccountInfo

Change client code to work as if IdentityManager::GetPrimaryAccount
where returning a CoreAccountInfo instead of an AccountInfo. Method
will be updated in a followup CL.

Bug: 926204
Change-Id: I0941676744c9e0f277862e5f58999dc3635bd71e
Reviewed-on: https://chromium-review.googlesource.com/c/1482465
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Nathan Parker <nparker@chromium.org>
Reviewed-by: Nathan Parker <nparker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634794}

chrome/browser/safe_browsing/advanced_protection_status_manager.cc

@@ -56,11 +56,11 @@ void AdvancedProtectionStatusManager::Initialize() {
 
 void AdvancedProtectionStatusManager::MaybeRefreshOnStartUp() {
   // Retrieves advanced protection service status from primary account's info.
-  AccountInfo info = identity_manager_->GetPrimaryAccountInfo();
-  if (info.account_id.empty())
+  CoreAccountInfo core_info = identity_manager_->GetPrimaryAccountInfo();
+  if (core_info.account_id.empty())
     return;
 
-  is_under_advanced_protection_ = info.is_under_advanced_protection;
+  is_under_advanced_protection_ = core_info.is_under_advanced_protection;
 
   if (profile_->GetPrefs()->HasPrefPath(
           prefs::kAdvancedProtectionLastRefreshInUs)) {