Profile chooser on mac was passing wrong value to signin error controller.

components/signin/ios/browser/profile_oauth2_token_service_ios.mm

Index: components/signin/ios/browser/profile_oauth2_token_service_ios.mm
diff --git a/components/signin/ios/browser/profile_oauth2_token_service_ios.mm b/components/signin/ios/browser/profile_oauth2_token_service_ios.mm
index a305f081b37aa39fef4fd10c58f73b40954a6e85..2eb3cff42429ff2564df047782c82c5e57351f19 100644
--- a/components/signin/ios/browser/profile_oauth2_token_service_ios.mm
+++ b/components/signin/ios/browser/profile_oauth2_token_service_ios.mm
@@ -162,12 +162,6 @@ std::string ProfileOAuth2TokenServiceIOS::AccountInfo::GetAccountId() const {
   return account_id_;
 }
 
-std::string ProfileOAuth2TokenServiceIOS::AccountInfo::GetUsername() const {
-  // TODO(rogerta): when |account_id| becomes the obfuscated gaia id, this
-  // will need to be changed.
-  return account_id_;
-}
-
 GoogleServiceAuthError
 ProfileOAuth2TokenServiceIOS::AccountInfo::GetAuthStatus() const {
   return last_auth_error_;