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

remoting/host/native_messaging/native_messaging_pipe.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 "remoting/host/native_messaging/native_messaging_pipe.h"
 
 #include "base/callback_helpers.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/values.h"
 
 namespace remoting {
 
 NativeMessagingPipe::NativeMessagingPipe() {
 }
 
 NativeMessagingPipe::~NativeMessagingPipe() {
 }
 
 void NativeMessagingPipe::Start(
     scoped_ptr<extensions::NativeMessageHost> host,
     scoped_ptr<extensions::NativeMessagingChannel> channel) {
   host_ = host.Pass();
   channel_ = channel.Pass();
   channel_->Start(this);
 }
 
 void NativeMessagingPipe::OnMessage(scoped_ptr<base::Value> message) {
   std::string message_json;
-  base::JSONWriter::Write(message.get(), &message_json);
+  base::JSONWriter::Write(*message, &message_json);
   host_->OnMessage(message_json);
 }
 
 void NativeMessagingPipe::OnDisconnect() {
   host_.reset();
   channel_.reset();
 }
 
 void NativeMessagingPipe::PostMessageFromNativeHost(
     const std::string& message) {
   scoped_ptr<base::Value> json(base::JSONReader::Read(message));
   channel_->SendMessage(json.Pass());
 }
 
 void NativeMessagingPipe::CloseChannel(const std::string& error_message) {
   host_.reset();
   channel_.reset();
 }
 
 }  // namespace remoting