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

cloud_print/gcp20/prototype/printer.cc

 // 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.
 
 #include "cloud_print/gcp20/prototype/printer.h"
 
 #include <limits.h>
 #include <stdio.h>
 #include <algorithm>
 #include <string>
@@ skipping 175 matching lines @@
     return;
   dns_server_.Shutdown();
   http_server_.Shutdown();
   requester_.reset();
   print_job_handler_.reset();
   xmpp_listener_.reset();
 }
 
 std::string Printer::GetRawCdd() {
   std::string json_str;
-  base::JSONWriter::WriteWithOptions(&GetCapabilities(),
+  base::JSONWriter::WriteWithOptions(GetCapabilities(),
                                      base::JSONWriter::OPTIONS_PRETTY_PRINT,
                                      &json_str);
   return json_str;
 }
 
 void Printer::OnAuthError() {
   LOG(ERROR) << "Auth error occurred";
   state_.access_token_update = base::Time();
   FallOffline(true);
 }
@@ skipping 749 matching lines @@
 
   dns_server_.UpdateMetadata(CreateTxt());
 
   if (connection_state_ == OFFLINE) {
     requester_.reset();
     xmpp_listener_.reset();
   }
 
   return true;
 }