Convert UserPolicySigninService to use OAuth2TokenService

chrome/browser/policy/cloud/user_policy_signin_service_base.cc

Index: chrome/browser/policy/cloud/user_policy_signin_service_base.cc
diff --git a/chrome/browser/policy/cloud/user_policy_signin_service_base.cc b/chrome/browser/policy/cloud/user_policy_signin_service_base.cc
index 2b78d89f5402e68c37ebad4aa59f9a477725fdda..7f832ca03c44f2de6b090f4c03961774fca5ef4d 100644
--- a/chrome/browser/policy/cloud/user_policy_signin_service_base.cc
+++ b/chrome/browser/policy/cloud/user_policy_signin_service_base.cc
@@ -129,6 +129,10 @@ void UserPolicySigninServiceBase::OnClientError(CloudPolicyClient* client) {
 }
 
 void UserPolicySigninServiceBase::Shutdown() {
+  PrepareForUserCloudPolicyManagerShutdown();
+}
+
+void UserPolicySigninServiceBase::PrepareForUserCloudPolicyManagerShutdown() {
   UserCloudPolicyManager* manager = GetManager();
   if (manager && manager->core()->client())
     manager->core()->client()->RemoveObserver(this);
@@ -230,7 +234,7 @@ void UserPolicySigninServiceBase::InitializeUserCloudPolicyManager(
 }
 
 void UserPolicySigninServiceBase::ShutdownUserCloudPolicyManager() {
-  Shutdown();
+  PrepareForUserCloudPolicyManagerShutdown();
   UserCloudPolicyManager* manager = GetManager();
   if (manager)
     manager->DisconnectAndRemovePolicy();