Proper management for policy-configured networks.

chrome/browser/policy/network_configuration_updater.cc

 // Copyright (c) 2011 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 "chrome/browser/policy/network_configuration_updater.h"
 
 #include "chrome/browser/chromeos/cros/network_library.h"
 #include "chrome/browser/policy/policy_map.h"
 #include "policy/policy_constants.h"
 
 namespace policy {
 
+const char NetworkConfigurationUpdater::kEmptyConfiguration[] =
+    "{NetworkConfigurations:[],Certificates:[]}";
+
 NetworkConfigurationUpdater::NetworkConfigurationUpdater(
     ConfigurationPolicyProvider* provider,
     chromeos::NetworkLibrary* network_library)
     : network_library_(network_library) {
   DCHECK(network_library_);
   provider_registrar_.Init(provider, this);
   Update();
 }
 
 NetworkConfigurationUpdater::~NetworkConfigurationUpdater() {}
@@ skipping 27 matching lines @@
     std::string* cached_value) {
   std::string new_network_config;
   const base::Value* value = policy_map.Get(policy_type);
   if (value != NULL) {
     // If the policy is not a string, we issue a warning, but still clear the
     // network configuration.
     if (!value->GetAsString(&new_network_config))
       LOG(WARNING) << "Invalid network configuration.";
   }
 
+  // We need to load an empty configuration to get rid of any configuration
+  // that has been installed previously. An empty string also works, but
+  // generates warnings and errors, which we'd like to avoid.
+  if (new_network_config.empty())
+    new_network_config = kEmptyConfiguration;
+
   if (*cached_value != new_network_config) {
     *cached_value = new_network_config;
     std::string error;
     if (!network_library_->LoadOncNetworks(new_network_config, "", onc_source,
                                            &error)) {
       LOG(WARNING) << "Network library failed to load ONC configuration:"
                    << error;
     }
   }
 }
 
 }  // namespace policy