Added Aura notification that relaunch and powerwash is required in case of downgrade.

BUG=260649
TEST=manual tests on a falco device

Review URL: https://codereview.chromium.org/614363002

Cr-Commit-Position: refs/heads/master@{#298408}
diff --git a/chrome/browser/upgrade_detector.cc b/chrome/browser/upgrade_detector.cc
index eff168d..b840035 100644
--- a/chrome/browser/upgrade_detector.cc
+++ b/chrome/browser/upgrade_detector.cc
@@ -62,6 +62,7 @@
       best_effort_experiment_updates_available_(false),
       critical_experiment_updates_available_(false),
       critical_update_acknowledged_(false),
+      is_factory_reset_required_(false),
       upgrade_notification_stage_(UPGRADE_ANNOYANCE_NONE),
       notify_upgrade_(false) {
 }