Convert JsonWriter::Write to taking a const ref for the in-param

chrome/browser/chromeos/proxy_config_service_impl_unittest.cc

 // 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.
 
 #include "chrome/browser/chromeos/proxy_config_service_impl.h"
 
 #include <vector>
 
 #include "base/format_macros.h"
 #include "base/json/json_writer.h"
@@ skipping 315 matching lines @@
         new_config.reset(ProxyConfigDictionary::CreateFixedServers(
             input.server, input.bypass_rules));
         break;
     }
     result->Swap(new_config.get());
   }
 
   void SetUserConfigInShill(base::DictionaryValue* pref_proxy_config_dict) {
     std::string proxy_config;
     if (pref_proxy_config_dict)
-      base::JSONWriter::Write(pref_proxy_config_dict, &proxy_config);
+      base::JSONWriter::Write(*pref_proxy_config_dict, &proxy_config);
 
     NetworkStateHandler* network_state_handler =
         NetworkHandler::Get()->network_state_handler();
     const NetworkState* network = network_state_handler->DefaultNetwork();
     ASSERT_TRUE(network);
     DBusThreadManager::Get()->GetShillServiceClient()->GetTestInterface()->
         SetServiceProperty(network->path(),
                            shill::kProxyConfigProperty,
                            base::StringValue(proxy_config));
   }
@@ skipping 167 matching lines @@
                                 network_configs.release());
 
   net::ProxyConfig actual_config;
   SyncGetLatestProxyConfig(&actual_config);
   net::ProxyConfig expected_config =
       net::ProxyConfig::CreateFromCustomPacURL(GURL("http://domain.com/x"));
   EXPECT_TRUE(expected_config.Equals(actual_config));
 }
 
 }  // namespace chromeos