Add presubmit check for scoped_ptr usage.

ui/app_list/search/dictionary_data_store.cc

Index: ui/app_list/search/dictionary_data_store.cc
diff --git a/ui/app_list/search/dictionary_data_store.cc b/ui/app_list/search/dictionary_data_store.cc
index 41ac884709acc80eca1cc41da0539263694dabd7..b867be4d743468fb2de5ccb81fc96dbcaf25e8c6 100644
--- a/ui/app_list/search/dictionary_data_store.cc
+++ b/ui/app_list/search/dictionary_data_store.cc
@@ -71,12 +71,12 @@ scoped_ptr<base::DictionaryValue> DictionaryDataStore::LoadOnBlockingPool() {
   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) {