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

chrome/browser/supervised_user/child_accounts/permission_request_creator_apiary.cc

 // Copyright 2014 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/supervised_user/child_accounts/permission_request_creator_apiary.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
@@ skipping 172 matching lines @@
   (*it)->url_fetcher->SetAutomaticallyRetryOnNetworkChanges(kNumRetries);
   (*it)->url_fetcher->AddExtraRequestHeader(
       base::StringPrintf(kAuthorizationHeaderFormat, access_token.c_str()));
 
   base::DictionaryValue dict;
   dict.SetStringWithoutPathExpansion(kEventTypeKey, (*it)->request_type);
   dict.SetStringWithoutPathExpansion(kObjectRefKey, (*it)->object_ref);
   dict.SetStringWithoutPathExpansion(kStateKey, kState);
 
   std::string body;
-  base::JSONWriter::Write(&dict, &body);
+  base::JSONWriter::Write(dict, &body);
   (*it)->url_fetcher->SetUploadData("application/json", body);
 
   (*it)->url_fetcher->Start();
 }
 
 void PermissionRequestCreatorApiary::OnGetTokenFailure(
     const OAuth2TokenService::Request* request,
     const GoogleServiceAuthError& error) {
   VLOG(1) << "Couldn't get token";
   RequestIterator it = requests_.begin();
@@ skipping 70 matching lines @@
       it, GoogleServiceAuthError::FromConnectionError(error_code));
 }
 
 void PermissionRequestCreatorApiary::DispatchGoogleServiceAuthError(
     RequestIterator it,
     const GoogleServiceAuthError& error) {
   VLOG(1) << "GoogleServiceAuthError: " << error.ToString();
   (*it)->callback.Run(false);
   requests_.erase(it);
 }