Add a check for server and CA certificates in device policies to the ONC validator.

chromeos/network/onc/onc_validator.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROMEOS_NETWORK_ONC_ONC_VALIDATOR_H_
 #define CHROMEOS_NETWORK_ONC_ONC_VALIDATOR_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 192 matching lines @@
 
   bool FieldExistsAndHasNoValidValue(const base::DictionaryValue& object,
                                      const std::string &field_name,
                                      const char** valid_values);
 
   bool FieldExistsAndIsNotInRange(const base::DictionaryValue& object,
                                   const std::string &field_name,
                                   int lower_bound,
                                   int upper_bound);
 
+  bool FieldExistsAndIsEmpty(const base::DictionaryValue& object,
+                             const std::string& field_name);
+
   bool RequireField(const base::DictionaryValue& dict, const std::string& key);
 
   bool CertPatternInDevicePolicy(const std::string& cert_type);
 
   std::string WarningHeader();
   std::string ErrorHeader();
   std::string MessageHeader(bool is_error);
 
   const bool error_on_unknown_field_;
   const bool error_on_wrong_recommended_;
@@ skipping 10 matching lines @@
   // function ValidateAndRepairObject.
   bool error_or_warning_found_;
 
   DISALLOW_COPY_AND_ASSIGN(Validator);
 };
 
 }  // namespace onc
 }  // namespace chromeos
 
 #endif  // CHROMEOS_NETWORK_ONC_ONC_VALIDATOR_H_