Cleanup: Pass std::string as const reference if possible

chromeos/network/shill_property_util.h

 // Copyright 2013 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_SHILL_PROPERTY_UTIL_H_
 #define CHROMEOS_NETWORK_SHILL_PROPERTY_UTIL_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "chromeos/chromeos_export.h"
 
 namespace base {
 class DictionaryValue;
 class Value;
 }
 
 namespace chromeos {
 
 class NetworkUIData;
 
 namespace shill_property_util {
 
 // Sets the |ssid| in |properties|.
-CHROMEOS_EXPORT void SetSSID(const std::string ssid,
+CHROMEOS_EXPORT void SetSSID(const std::string& ssid,
                              base::DictionaryValue* properties);
 
 // Returns the SSID from |properties| in UTF-8 encoding. If |verbose_logging| is
 // true, detailed DEBUG log events will be added to the device event log. If
 // |unknown_encoding| != nullptr, it is set to whether the SSID is of unknown
 // encoding.
 CHROMEOS_EXPORT std::string GetSSIDFromProperties(
     const base::DictionaryValue& properties,
     bool verbose_logging,
     bool* unknown_encoding);
@@ skipping 57 matching lines @@
 // Parses |value| (which should be a Dictionary). Returns true and sets
 // |home_provider_id| if |value| was succesfully parsed.
 bool GetHomeProviderFromProperty(const base::Value& value,
                                  std::string* home_provider_id);
 
 }  // namespace shill_property_util
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_NETWORK_SHILL_PROPERTY_UTIL_H_