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

chrome/browser/extensions/api/messaging/native_message_host_chromeos.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 "extensions/browser/api/messaging/native_message_host.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 52 matching lines @@
       ProcessEcho(*request);
     }
   };
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner() const override {
     return base::ThreadTaskRunnerHandle::Get();
   };
 
  private:
   void ProcessEcho(const base::DictionaryValue& request) {
-    scoped_ptr<base::DictionaryValue> response(new base::DictionaryValue());
-    response->SetInteger("id", ++message_number_);
-    response->Set("echo", request.DeepCopy());
-    response->SetString("caller_url", kEchoHostOrigins[0]);
+    base::DictionaryValue response;
+    response.SetInteger("id", ++message_number_);
+    response.Set("echo", request.CreateDeepCopy());
+    response.SetString("caller_url", kEchoHostOrigins[0]);
     std::string response_string;
-    base::JSONWriter::Write(response.get(), &response_string);
+    base::JSONWriter::Write(response, &response_string);
     client_->PostMessageFromNativeHost(response_string);
   }
 
   int message_number_;
   Client* client_;
 
   DISALLOW_COPY_AND_ASSIGN(EchoHost);
 };
 
 struct BuiltInHost {
@@ skipping 76 matching lines @@
       }
       *error = kForbiddenError;
       return nullptr;
     }
   }
   *error = kNotFoundError;
   return nullptr;
 }
 
 }  // namespace extensions