Disable sync consent for non-Gaia users

Now it is displayed for Active Directory users even though sync does not
work for them.

BUG=chromium:814777
TEST=manual

Change-Id: I34ca96cc84f6a630947d9224b954522fface1af1
Reviewed-on: https://chromium-review.googlesource.com/970912
Commit-Queue: Alexander Alekseev <alemate@chromium.org>
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544891}

chrome/browser/chromeos/login/wizard_controller.cc

@@ -590,8 +590,9 @@ void WizardController::ShowSyncConsentScreen() {
 #if defined(GOOGLE_CHROME_BUILD)
   const user_manager::UserManager* user_manager =
       user_manager::UserManager::Get();
-  // Skip for non-regular users.
-  if (user_manager->IsLoggedInAsPublicAccount() ||
+  // Skip for non-regular users and for users without Gaia account.
+  if (!user_manager->IsLoggedInAsUserWithGaiaAccount() ||
+      user_manager->IsLoggedInAsPublicAccount() ||
       (user_manager->IsCurrentUserNonCryptohomeDataEphemeral() &&
        user_manager->GetActiveUser()->GetType() !=
            user_manager::USER_TYPE_REGULAR)) {