Add presubmit check for scoped_ptr usage.

ui/app_list/search/dictionary_data_store.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 "ui/app_list/search/dictionary_data_store.h"
 
 #include "base/callback.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/logging.h"
@@ skipping 53 matching lines @@
 scoped_ptr<base::DictionaryValue> DictionaryDataStore::LoadOnBlockingPool() {
   DCHECK(worker_pool_->RunsTasksOnCurrentThread());
 
   int error_code = JSONFileValueSerializer::JSON_NO_ERROR;
   std::string error_message;
   JSONFileValueSerializer serializer(data_file_);
   base::Value* value = serializer.Deserialize(&error_code, &error_message);
   base::DictionaryValue* dict_value = NULL;
   if (error_code != JSONFileValueSerializer::JSON_NO_ERROR || !value ||
       !value->GetAsDictionary(&dict_value) || !dict_value) {
-    return scoped_ptr<base::DictionaryValue>();
+    return nullptr;
   }
 
   base::DictionaryValue* return_dict = dict_value->DeepCopy();
   cached_dict_.reset(dict_value);
-  return make_scoped_ptr(return_dict).Pass();
+  return make_scoped_ptr(return_dict);
 }
 
 bool DictionaryDataStore::SerializeData(std::string* data) {
   JSONStringValueSerializer serializer(data);
   serializer.set_pretty_print(true);
   return serializer.Serialize(*cached_dict_.get());
 }
 
 }  // namespace app_list