Override SigninManager::SignOut if force-signin is enabled.

components/signin/core/browser/signin_manager.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/signin_manager.h"
 
 #include <string>
 #include <vector>
 
 #include "base/metrics/histogram_macros.h"
@@ skipping 107 matching lines @@
   }
 }
 
 void SigninManager::CopyCredentialsFrom(const SigninManager& source) {
   DCHECK_NE(this, &source);
   possibly_invalid_account_id_ = source.possibly_invalid_account_id_;
   possibly_invalid_gaia_id_ = source.possibly_invalid_gaia_id_;
   possibly_invalid_email_ = source.possibly_invalid_email_;
   temp_refresh_token_ = source.temp_refresh_token_;
   password_ = source.password_;
+  source.client_->AfterCredentialsCopied();
 }
 
 void SigninManager::ClearTransientSigninData() {
   DCHECK(IsInitialized());
 
   possibly_invalid_account_id_.clear();
   possibly_invalid_gaia_id_.clear();
   possibly_invalid_email_.clear();
   password_.clear();
   type_ = SIGNIN_TYPE_NONE;
   temp_refresh_token_.clear();
 }
 
 void SigninManager::HandleAuthError(const GoogleServiceAuthError& error) {
   ClearTransientSigninData();
 
   for (auto& observer : observer_list_)
     observer.GoogleSigninFailed(error);
 }
 
 void SigninManager::SignOut(
     signin_metrics::ProfileSignout signout_source_metric,
     signin_metrics::SignoutDelete signout_delete_metric) {
+  client_->PreSignOut(base::Bind(&SigninManager::DoSignOut,
+                                 base::Unretained(this), signout_source_metric,
+                                 signout_delete_metric));
+}
+
+void SigninManager::DoSignOut(
+    signin_metrics::ProfileSignout signout_source_metric,
+    signin_metrics::SignoutDelete signout_delete_metric) {
   DCHECK(IsInitialized());
 
   signin_metrics::LogSignout(signout_source_metric, signout_delete_metric);
   if (!IsAuthenticated()) {
     if (AuthInProgress()) {
       // If the user is in the process of signing in, then treat a call to
       // SignOut as a cancellation request.
       GoogleServiceAuthError error(GoogleServiceAuthError::REQUEST_CANCELED);
       HandleAuthError(error);
     } else {
@@ skipping 254 matching lines @@
     account_tracker_service()->SetMigrationDone();
     token_service_->RemoveObserver(this);
   }
 }
 
 void SigninManager::ProhibitSignout(bool prohibit_signout) {
   prohibit_signout_ = prohibit_signout;
 }
 
 bool SigninManager::IsSignoutProhibited() const { return prohibit_signout_; }