Add a SigninAllowed policy.

chrome/browser/policy/configuration_policy_handler.cc

Index: chrome/browser/policy/configuration_policy_handler.cc
diff --git a/chrome/browser/policy/configuration_policy_handler.cc b/chrome/browser/policy/configuration_policy_handler.cc
index 5587cae14c2c6582bdbdd08633edf7282a5e7b15..ea01c560c001c090bffbf60c52fe1b7bc26b52c4 100644
--- a/chrome/browser/policy/configuration_policy_handler.cc
+++ b/chrome/browser/policy/configuration_policy_handler.cc
@@ -553,6 +553,23 @@ void SyncPolicyHandler::ApplyPolicySettings(const PolicyMap& policies,
     prefs->SetValue(prefs::kSyncManaged, value->DeepCopy());
 }
 
+// SigninPolicyHandler implementation ------------------------------------------
+
+SigninPolicyHandler::SigninPolicyHandler()
+    : TypeCheckingPolicyHandler(key::kSigninAllowed,
+                                Value::TYPE_BOOLEAN) {
+}
+
+SigninPolicyHandler::~SigninPolicyHandler() {
+}
+
+void SigninPolicyHandler::ApplyPolicySettings(const PolicyMap& policies,
+                                              PrefValueMap* prefs) {
+  const Value* value = policies.GetValue(policy_name());
+  bool signin_allowed;
+  if (value && value->GetAsBoolean(&signin_allowed))

[Andrew T Wilson (Slow), 2013/02/07 10:08:11]

This is fine with me, but I wonder if this boilerplate is really necessary. You
might ask one of the policy folks like Joao if there's a way to do this with
less boilerplate.

[Adrian Kuegel, 2013/02/07 11:09:21]

Yes, I will do that. I did this part just in the same way as I have seen for the
syncManaged policy, so I didn't look into it if there is a better way.

+    prefs->SetValue(prefs::kSigninAllowed, value->DeepCopy());
+}
 
 // AutofillPolicyHandler implementation ----------------------------------------