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

components/signin/core/browser/fake_auth_status_provider.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/signin/core/browser/fake_auth_status_provider.h"
 
 FakeAuthStatusProvider::FakeAuthStatusProvider(SigninErrorController* error)
   : error_provider_(error),
     auth_error_(GoogleServiceAuthError::AuthErrorNone()) {
   error_provider_->AddProvider(this);
 }
 
 FakeAuthStatusProvider::~FakeAuthStatusProvider() {
   error_provider_->RemoveProvider(this);
 }
 
 std::string FakeAuthStatusProvider::GetAccountId() const {
   return account_id_;
 }
 
-std::string FakeAuthStatusProvider::GetUsername() const {
-  return username_;
-}
-
 GoogleServiceAuthError FakeAuthStatusProvider::GetAuthStatus() const {
   return auth_error_;
 }
 
 void FakeAuthStatusProvider::SetAuthError(const std::string& account_id,
-                                          const std::string& username,
                                           const GoogleServiceAuthError& error) {
   account_id_ = account_id;
-  username_ = username;
   auth_error_ = error;
   error_provider_->AuthStatusChanged();
 }