Cleanup usage of scoped_ptr<> in remoting for C++11

remoting/host/it2me/it2me_native_messaging_host_unittest.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 "remoting/host/it2me/it2me_native_messaging_host.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
@@ skipping 243 matching lines @@
   output_read_file_.Close();
 }
 
 scoped_ptr<base::DictionaryValue>
 It2MeNativeMessagingHostTest::ReadMessageFromOutputPipe() {
   uint32 length;
   int read_result = output_read_file_.ReadAtCurrentPos(
       reinterpret_cast<char*>(&length), sizeof(length));
   if (read_result != sizeof(length)) {
     // The output pipe has been closed, return an empty message.
-    return scoped_ptr<base::DictionaryValue>();
+    return nullptr;
   }
 
   std::string message_json(length, '\0');
   read_result = output_read_file_.ReadAtCurrentPos(
       string_as_array(&message_json), length);
   if (read_result != static_cast<int>(length)) {
     LOG(ERROR) << "Message size (" << read_result
                << ") doesn't match the header (" << length << ").";
-    return scoped_ptr<base::DictionaryValue>();
+    return nullptr;
   }
 
   scoped_ptr<base::Value> message(base::JSONReader::Read(message_json));
   if (!message || !message->IsType(base::Value::TYPE_DICTIONARY)) {
     LOG(ERROR) << "Malformed message:" << message_json;
-    return scoped_ptr<base::DictionaryValue>();
+    return nullptr;
   }
 
   return scoped_ptr<base::DictionaryValue>(
       static_cast<base::DictionaryValue*>(message.release()));
 }
 
 void It2MeNativeMessagingHostTest::WriteMessageToInputPipe(
     const base::Value& message) {
   std::string message_json;
   base::JSONWriter::Write(&message, &message_json);
@@ skipping 257 matching lines @@
 
 // Verify rejection if type is unrecognized.
 TEST_F(It2MeNativeMessagingHostTest, InvalidType) {
   base::DictionaryValue message;
   message.SetString("type", "xxx");
   TestBadRequest(message, true);
 }
 
 }  // namespace remoting