Implement new password separated sign in flow for chrome desktop.

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
index 34c61120f6cc61fb28641bd50aa29d52c23725ff..fdd83b3d0ccca8fde145650414cafdf755c5d1f9 100644
--- a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc
@@ -231,6 +231,7 @@ void GaiaScreenHandler::LoadGaiaWithVersion(
   params.SetBoolean("isShowUsers", context.show_users);
   params.SetBoolean("useOffline", context.use_offline);
   params.SetString("gaiaId", context.gaia_id);
+  params.SetBoolean("readOnlyEmail", true);
   params.SetString("email", context.email);
   params.SetBoolean("isEnrollingConsumerManagement",
                     is_enrolling_consumer_management);