When comparing emails in the one click signin helper, use the existing utility

chrome/browser/ui/sync/one_click_signin_helper.cc

Index: chrome/browser/ui/sync/one_click_signin_helper.cc
diff --git a/chrome/browser/ui/sync/one_click_signin_helper.cc b/chrome/browser/ui/sync/one_click_signin_helper.cc
index 59fc87c678ae878306ee373281f2b81215e00769..8240c194c8c035ae8ff900f174d9ed407d7f253f 100644
--- a/chrome/browser/ui/sync/one_click_signin_helper.cc
+++ b/chrome/browser/ui/sync/one_click_signin_helper.cc
@@ -1184,7 +1184,7 @@ void OneClickSigninHelper::DidStopLoading(
       std::string last_email =
           profile->GetPrefs()->GetString(prefs::kGoogleServicesLastUsername);
 
-      if (!last_email.empty() && last_email != email_) {
+      if (!last_email.empty() && !gaia::AreEmailsSame(last_email, email_)) {
         // If the new email address is different from the email address that
         // just signed in, show a confirmation dialog.