Remove references to IsNewAvatarMenu since the flag was removed.

chrome/browser/signin/signin_promo.cc

Index: chrome/browser/signin/signin_promo.cc
diff --git a/chrome/browser/signin/signin_promo.cc b/chrome/browser/signin/signin_promo.cc
index 0637886778a4c363e2bbe264b2b937f7082779e0..9db75c826cf8fbd6ad0365ea3f98560e8645899e 100644
--- a/chrome/browser/signin/signin_promo.cc
+++ b/chrome/browser/signin/signin_promo.cc
@@ -197,12 +197,9 @@ GURL GetReauthURL(Profile* profile, const std::string& account_id) {
 }
 
 GURL GetReauthURLWithEmail(const std::string& email) {
-  signin_metrics::Source source = switches::IsNewAvatarMenu() ?
-      signin_metrics::SOURCE_REAUTH : signin_metrics::SOURCE_SETTINGS;
-
   GURL url = signin::GetPromoURL(
-      source, true /* auto_close */,
-      switches::IsNewAvatarMenu() /* is_constrained */);
+      signin_metrics::SOURCE_REAUTH, true /* auto_close */,
+      true /* is_constrained */);
 
   url = net::AppendQueryParameter(url, "email", email);
   url = net::AppendQueryParameter(url, "validateEmail", "1");