Revert of Access SigninErrorProvider through ChromeBrowserProvider.

ios/public/provider/chrome/browser/chrome_browser_provider.mm

 // Copyright 2013 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 "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 
 #include <cstddef>
 
 #include "base/logging.h"
 #include "components/metrics/metrics_provider.h"
@@ skipping 28 matching lines @@
 ChromeBrowserProvider::GetUpdatableResourceProvider() {
   return nullptr;
 }
 
 InfoBarViewPlaceholder ChromeBrowserProvider::CreateInfoBarView(
     CGRect frame,
     InfoBarViewDelegate* delegate) {
   return nullptr;
 }
 
-SigninErrorProvider* ChromeBrowserProvider::GetSigninErrorProvider() {
-  return nullptr;
-}
-
 SigninResourcesProvider* ChromeBrowserProvider::GetSigninResourcesProvider() {
   return nullptr;
 }
 
 void ChromeBrowserProvider::SetChromeIdentityServiceForTesting(
     std::unique_ptr<ChromeIdentityService> service) {}
 
 ChromeIdentityService* ChromeBrowserProvider::GetChromeIdentityService() {
   return nullptr;
 }
@@ skipping 65 matching lines @@
 
 NSArray* ChromeBrowserProvider::GetAvailableVoiceSearchLanguages() const {
   return [NSArray array];
 }
 
 VoiceSearchProvider* ChromeBrowserProvider::GetVoiceSearchProvider() const {
   return nullptr;
 }
 
 }  // namespace ios